# Interior Construction Details Mastery Reference

> Comprehensive reference for cabinetry, millwork, bathrooms, stairs, ceilings, floor transitions, and fire-rated assemblies. Dimensions, code references, product types, and drawing standards for professional CD sets.

---

## 1. CABINETRY & MILLWORK DETAILS

### 1.1 AWI Quality Grades (Architectural Woodwork Institute)

The AWI Standards (AWI 100-800 series) define three quality grades for all architectural woodwork:

| Grade | Use | Description |
|-------|-----|-------------|
| **Economy** | Utility, back-of-house, mechanical rooms | Minimum quality for materials, workmanship, and installation. Not intended for public view. |
| **Custom** | General commercial, residential | Mid-range quality. **Default grade if none specified.** Good balance of cost and appearance. |
| **Premium** | Executive areas, lobbies, boardrooms | Highest quality. Tightest tolerances, best material selection, finest craftsmanship. |

**Key AWI Standard Sections:**
- AWI 100: Submittal (shop drawing standards, material data, construction methods)
- AWI 200: Care and Storage
- AWI 300: Materials (lumber, panel cores, panel surfaces, veneers)
- AWI 400: Architectural Wood Casework
- AWI 500: Architectural Wood Paneling & Wainscot
- AWI 600: Architectural Wood Doors
- AWI 700: Standing & Running Trim
- AWI 800: Closet and Utility Shelving

**Tolerance Summary by Grade:**

| Measurement | Economy | Custom | Premium |
|-------------|---------|--------|---------|
| Face frame flush | 1/32" | 1/64" | 1/64" |
| Door/drawer gap | 3/32" | 1/16" | 1/16" |
| Warp (door) | 3/16" | 1/8" | 1/16" |
| Joint gaps | 1/32" | 1/64" | Hairline |

### 1.2 Standard Cabinet Dimensions

#### Base Cabinets
```
                    Countertop (1-1/2" thick)
                    ________________________
                   |                        |
    36" total  --> |   Cabinet Box          | <-- 24" deep (21" face to back of box)
    height         |   34-1/2" to top       |
                   |   of cabinet           |
                   |________________________|
                   |   Toe Kick             | <-- 4-1/2" high x 3" deep recess
                   |________________________|
                        FLOOR

    Standard widths: 9", 12", 15", 18", 21", 24", 27", 30", 33", 36", 42", 48"
    Shelf spacing: 10-12" typical
    Drawer heights: 4", 6", 8", 10" (front height)
```

**Key Dimensions:**
- Height: 34-1/2" (cabinet box) + 1-1/2" (countertop) = 36" total
- Depth: 24" (including face frame); box depth typically 21"
- Toe kick: 4-1/2" high x 3" deep (min 3" high per ADA)
- Face frame: 1-1/2" wide stiles, 1-1/2" to 2" rails
- Frameless (European): 3/4" box sides, no face frame, 32mm system boring

#### Upper (Wall) Cabinets
```
    ________________________
   |                        |
   |   Cabinet Box          | <-- 12" or 15" deep
   |   30", 36", or 42"    |     (12" standard, 15" over refrigerator)
   |   tall                 |
   |________________________|

    18" above countertop (min clearance)
    54" to top of 30" cabinet
    66" to top of 42" cabinet
    Standard widths: 9", 12", 15", 18", 21", 24", 27", 30", 33", 36"
```

**Key Dimensions:**
- Height: 30" (standard), 36", 42" (to ceiling)
- Depth: 12" (standard), 15" (microwave/refrigerator cabinets)
- Bottom of upper to countertop: 18" (standard), 15" (min), 24" (above range)
- Mounting height: 54" AFF to bottom of 30" cabinet

#### Tall (Pantry/Utility) Cabinets
```
    ________________________
   |                        |
   |   Cabinet Box          | <-- 12", 18", or 24" deep
   |   84", 90", or 96"    |
   |   tall                 |
   |________________________|

    Standard widths: 18", 24", 36"
    May include pull-out shelves, lazy susans, or built-in ovens
```

**Key Dimensions:**
- Height: 84" (standard), 90" (to 8' ceiling soffit), 96" (to 8' ceiling)
- Depth: 12" (shallow pantry), 24" (full depth, oven cabinet)
- Widths: 18", 24", 36"

#### Vanity Cabinets
```
    ________________________
   |                        |
   |   Vanity Box           | <-- 21" deep (standard)
   |   30"-33" tall         |     18" for powder rooms
   |   (or 34-1/2"         |
   |    comfort height)     |
   |________________________|
   |   Toe Kick             |
   |________________________|

    Standard widths: 24", 30", 36", 48", 60" (double), 72"
```

**Key Dimensions:**
- Height: 30"-33" (traditional), 34-1/2" (comfort/ADA height)
- Depth: 21" (standard), 18" (powder room), 24" (master bath)
- Single sink: 24"-48" wide
- Double sink: 60"-72" wide (min 60" for two basins)

### 1.3 Cabinet Construction Types

#### Framed (Face-Frame) Construction
```
    SECTION:
    ___________________________
   | FF |                 | FF |   FF = Face Frame (3/4" x 1-1/2" typical)
   |    |  3/4" Plywood   |    |   Side panel set back behind face frame
   |    |  or Particle Bd  |    |
   |    |  Side Panel      |    |   Hinges mount to face frame
   |____|_________________|____|
```
- Face frame: 3/4" x 1-1/2" hardwood (maple, oak, poplar)
- Box: 1/2" to 3/4" plywood or particleboard
- Back panel: 1/4" plywood or hardboard
- Bottom: 1/2" to 3/4" plywood or particleboard
- Shelves: 3/4" plywood or particleboard with edge banding

#### Frameless (European/32mm System) Construction
```
    SECTION:
    ___________________________
   |                           |   No face frame
   |  3/4" Plywood or MDF     |   Box sides are finished/edgebanded
   |  Side Panel               |   Hinges mount to side panels
   |  (edgebanded front)       |   32mm boring pattern for shelf pins
   |___________________________|
```
- Box sides: 3/4" (18mm) particleboard or plywood
- Back panel: 1/4" to 1/2"
- All visible edges edgebanded (PVC, ABS, or wood veneer)
- 32mm system: Vertical rows of 5mm holes at 32mm spacing for adjustable shelves/hardware
- Full overlay doors with 0-3mm reveal

#### Drawer Construction
```
    PLAN VIEW:
    ________________________________
   |  Drawer Front (3/4")           |
   |  ____________________________  |
   | | Drawer Side    | Drawer     | |
   | | (1/2"-5/8")    | Bottom     | |
   | |                | (1/4"-1/2")| |
   | |________________|____________| |
   |________________________________|

    JOINERY TYPES:
    - Dovetail (Premium): Interlocking pins and tails
    - Dowel (Custom): Dowel pins through butt joints
    - Dado (Economy): Side grooved into front/back
    - Stapled/Glued (Economy): Metal staples + adhesive
```

### 1.4 Countertop Edge Profiles

```
    EASED (Standard):         BULLNOSE (Half):        BULLNOSE (Full):
    ___________               ___________              ___________
   |           |             /           |             /           \
   |           |            |            |            |             |
   |___________|            |____________|            |_____________|

    OGEE:                    BEVELED:                  WATERFALL:
    ___  _____               ____________              ___________
       \/     |              \           |             |           |
       /\     |               \__________|             |           |
      /  \____|                                        |           |
                                                       |           |
                                                       |___________|

    DUPONT:                  MITERED:                  LAMINATED:
    ___ ______               ___________               ___________
       |      |             |          /               |           |
       |      |             |         /                |___________|
    ___|______|             |________/                 |           |
                            |_______/                  |___________|
```

**Edge Profile Selection by Material:**

| Material | Common Edges | Notes |
|----------|-------------|-------|
| Granite | Eased, bullnose, ogee, dupont, mitered | Can handle complex profiles |
| Quartz | Eased, beveled, bullnose, ogee, mitered | Most versatile for profiles |
| Marble | Eased, beveled, ogee | Softer stone, simpler profiles |
| Laminate | Eased, beveled, post-formed bullnose | Limited by veneer nature |
| Solid Surface | Any profile | Thermoformable, seamless joints |
| Butcher Block | Eased, beveled, bullnose | Wood grain limits complex profiles |
| Concrete | Eased, bullnose, custom | Cast to any shape |

**Countertop Thickness:**
- Granite/Quartz: 3/4" (2cm) or 1-1/4" (3cm); 3cm is standard for kitchens
- Laminate: 1-1/2" total (3/4" particleboard + build-up + laminate)
- Solid Surface: 1/2" or 3/4" (may use build-up strips for thicker edge)
- Butcher Block: 1-1/2" to 3"
- Concrete: 1-1/2" to 3" (min 1-1/2" for reinforcement)

**Overhang Dimensions:**
- Standard front overhang: 1" to 1-1/2" beyond face of cabinet
- Bar/eating overhang: 12"-15" (requires support brackets at 24" o.c. max if > 10")
- Island overhang support: Corbels, brackets, or steel angle at 24"-36" o.c.
- Max unsupported overhang (stone): 10" for 3cm, 6" for 2cm

### 1.5 Cabinet Anchorage Details

#### Wall-Mounted Upper Cabinets
```
    SECTION AT WALL MOUNT:
    ___________________________
   |                           |
   |  Cabinet Box              |
   |                           |    #10 x 3" screws through
   |  [Hanging Rail]=====[===>|    1/2" plywood back rail
   |                           |    into studs at 16" o.c.
   |___________________________|

    - Min 2 screws per stud hit (top & bottom rail)
    - Hanging rail: 3/4" x 4" plywood cleat at top of cabinet
    - French cleat alternative: 45-degree bevel, one piece on wall, one on cabinet
    - Toggle bolts for non-stud locations (supplemental only, not primary support)
    - Ledger board method: Temporary 1x4 at 54" AFF during installation
```

#### Base Cabinet Anchorage
```
    SECTION AT BASE:
    ___________________________
   | Countertop (shimmed level)|
   |___________________________|
   |                           |
   |  Cabinet Box              |    Screwed through back rail
   |  (shimmed plumb & level)  |    to studs with #10 x 2-1/2" screws
   |                           |
   |___________________________|
   |  Toe Kick                 |
   |__ ________________________|    Shims at floor as needed
       SUBFLOOR                     Adjacent cabinets bolted together
                                    through stiles with 1/4" bolts
```

#### French Cleat System
```
    SECTION:
              Wall Cleat (beveled)
              _______________
             /               |  Screwed to studs
    ________/                |  with lag screws
                             |
    Cabinet Cleat (beveled)
    _______________
   |               \
   |                \________   Attached to cabinet back
   |
   Cabinet hangs on interlocking bevels

   Bevel angle: 45 degrees
   Cleat material: 3/4" plywood or hardwood
   Width: 3-4" minimum
```

### 1.6 ADA-Compliant Cabinet Details

**Key ADA/ANSI A117.1 Requirements:**

```
    KITCHEN ELEVATION (ADA):

    Max reach: 48" AFF ------>  ________________________
                               |   Upper Cabinet       |
    Wall cabinet bottom        |   (within reach range) |
    48" max AFF ---------->    |________________________|

    18" clearance
                               ________________________
    Countertop 34" max -----> |________________________| <-- No deeper than 25"
                                                              for forward approach
    Knee clearance:            |                        |
    27" min high ---------->   |     OPEN (no base      |
    30" min wide               |     cabinet below      |
    19" min deep               |     accessible sink)   |
                               |                        |
    Toe clearance:             |________________________|
    9" min high                |  Toe space 6" deep min |
    6" min deep                |________________________|
                                    FLOOR
```

**ADA Dimensional Requirements:**
- Counter height: 34" max AFF (adjustable preferred: 28"-36")
- Knee clearance: 27" high x 30" wide x 19" deep minimum
- Toe clearance: 9" high x 6" deep minimum
- Forward reach (unobstructed): 15"-48" AFF
- Forward reach (over 20"-25" obstruction): 44"-48" max
- Side reach (unobstructed): 15"-48" AFF
- Clear floor space: 30" x 48" at each appliance/work surface
- Sink bowl depth: 6-1/2" max for knee clearance
- Hardware: Lever handles or pulls (no knobs requiring grasp/twist)
- Operating force: 5 lbs max for all operable parts
- Pull-out shelves recommended for base cabinets
- Lazy susans or pull-out organizers for corner cabinets

### 1.7 Hardware & Hinge Details

**Hinge Types:**
| Type | Application | Notes |
|------|-------------|-------|
| Concealed (Euro) | Frameless cabinets | 35mm cup, adjustable 3 ways |
| Semi-concealed | Face-frame cabinets | Visible barrel when closed |
| Butt hinge | Traditional/inset doors | Mortised into frame and door |
| Pivot hinge | Heavy doors | Top and bottom mounted |
| Piano hinge | Lid-style openings | Continuous full-length |
| Soft-close | All modern installations | Integrated or add-on damper |

**Concealed Hinge Boring:**
- Cup diameter: 35mm (standard)
- Cup depth: 11-13mm
- Distance from door edge: 3-5mm (overlay dependent)
- Mounting plate: 0mm, 3mm, or 6mm from cabinet edge

**Drawer Slide Types:**
| Type | Load Rating | Extension | Application |
|------|-------------|-----------|-------------|
| Side-mount roller | 50-75 lbs | 3/4 extension | Economy |
| Side-mount ball bearing | 75-100 lbs | Full extension | Custom |
| Undermount | 75-100 lbs | Full extension | Premium |
| Heavy-duty | 150-500 lbs | Full extension | Trash, file drawers |
| Soft-close | 75-100 lbs | Full extension + soft close | Standard modern |

---

## 2. BATHROOM & WET AREA DETAILS

### 2.1 Shower Pan Waterproofing Systems

#### Traditional Mortar Bed (TCNA Method B414)
```
    SECTION THROUGH SHOWER FLOOR:

    Tile (3/8" typical)
    Thinset mortar (1/8")
    ________________________________
    Mortar bed (1"-1-1/2" thick)     <-- Reinforced with wire mesh
    ________________________________     Sloped 1/4" per foot to drain
    Waterproof membrane               <-- CPE or PVC liner (Oatey, etc.)
    ________________________________     Lapped up walls 3" above curb
    Pre-slope mortar bed (3/4"-1")   <-- 1/4" per foot slope to drain
    ________________________________
    Subfloor (3/4" plywood min)

    DRAIN DETAIL:
    - Two-piece clamping drain (Oatey)
    - Lower drain body set in pre-slope
    - Membrane clamped between flanges with bolts
    - Weep holes in upper drain body allow water
      trapped above membrane to reach drain
    - 2" P-trap below (IPC requirement)
```

#### Thin-Set Waterproofing (Schluter KERDI System)
```
    SECTION THROUGH SHOWER FLOOR:

    Tile (3/8" typical)
    Thinset mortar (unmodified) (1/8")
    ________________________________
    KERDI membrane (8 mil polyethylene) <-- Fleece-backed, bonded in thinset
    ________________________________       Waterproof + vapor retarder
    KERDI-SHOWER-T tray               <-- Pre-sloped EPS foam tray
    (or mortar bed sloped 1/4"/ft)         with integrated KERDI membrane
    ________________________________
    Thinset mortar bed
    ________________________________
    Subfloor (3/4" plywood min)

    SEAM/JOINT DETAILS:
    - KERDI-BAND: 5" wide strip for all seams, corners, and floor-wall transitions
    - Overlaps: 2" minimum at sheet seams
    - All set in unmodified thinset (Schluter SET, ALL-SET, or FAST-SET)
    - Penetrations: KERDI-SEAL-PS pipe seals, KERDI-SEAL-MV mixing valve seals
```

#### Liquid-Applied Membrane (RedGard, HydroBan, AquaDefense)
```
    SECTION THROUGH SHOWER FLOOR:

    Tile
    Thinset mortar
    ________________________________
    Liquid membrane (2 coats)        <-- Roller or spray applied
    ________________________________     Cures to monolithic membrane
    Cement backer board or mortar bed    Reinforced at corners with fabric mesh
    ________________________________
    Subfloor

    APPLICATION REQUIREMENTS:
    - Min 2 coats, perpendicular directions
    - Wet film thickness: 25-30 mils per coat
    - Dry film thickness: 15-20 mils total (measure with mil gauge)
    - Cure time: 12-24 hours between coats (until color changes)
    - Fabric mesh at all corners, changes of plane, and joints
    - Extend waterproofing 3" above showerhead height on walls
```

### 2.2 Shower Curb Details

#### Standard Shower Curb
```
    SECTION THROUGH CURB:

                    Tile
                   /    \
                  /      \
    _____________/        \____________
   |   SHOWER   |  CURB   |  BATHROOM |
   |   FLOOR    | 2x4 or  |  FLOOR    |
   |            | 2x6     |           |
   |  Sloped    | blocking|           |
   |  1/4"/ft   |         |           |
   |            | Membrane|           |
   |____________| wraps   |___________|
                | over    |
                | top &   |
                | down    |
                | both    |
                | sides   |
    ____________|_________|____________
         SUBFLOOR

    CURB DIMENSIONS:
    - Width: 3-1/2" (2x4) or 5-1/2" (2x6) + tile/mortar
    - Height: 2" min above drain (finished), typically 4"-6" total
    - Slope: Top pitched 1/4" toward shower
    - Membrane: Must wrap completely over top and down both sides
    - Curb must be waterproofed before any tile installation
```

#### Schluter KERDI-CURB (Prefabricated)
```
    SECTION:

    Tile on all exposed faces
    Thinset (unmodified)
    ________________________________
    KERDI membrane (factory-applied)
    ________________________________
    EPS foam curb body
    (4-1/2" wide x 6" tall)
    ________________________________
    Thinset mortar bed
    ________________________________
    Subfloor

    - Factory-waterproofed: KERDI membrane pre-bonded
    - KERDI-BAND at curb-to-tray and curb-to-wall joints
    - Lightweight: easy to cut and shape
    - Available lengths: 38", 48", 60" (trimmable)
```

### 2.3 Curbless (Zero-Entry) Shower Details

```
    SECTION THROUGH CURBLESS TRANSITION:

    BATHROOM FLOOR                          SHOWER FLOOR
    _____________                           _____________
   |             |      LINEAR DRAIN       |             |
   |  Tile       |      ___________        |  Tile       |
   |  Thinset    |     |  |drain|  |       |  Thinset    |
   |  Substrate  |     |  |body |  |       |  KERDI      |
   |  Subfloor   |     |__|_____|__|       |  SHOWER-ST  |
   |_____________|_____|___________|_______|_____________|
                        Recessed subfloor
                        (depressed framing)

    CONSTRUCTION REQUIREMENTS (TCNA B421C/B422C):
    - MUST use sealed shower system (Schluter, Wedi, Laticrete Hydro Ban)
    - Subfloor must be recessed/depressed at shower area
    - Depression depth: 1-1/2" to 2" typical (accommodate slope + drain)
    - Slope: 1/4" per foot to drain (IPC requirement)
    - Linear drain: wall-to-wall installation preferred
    - Waterproofing extends min 36" beyond shower area onto bathroom floor
    - Transition strip at perimeter (Schluter RENO-T or DILEX)

    LINEAR DRAIN SPECIFICATIONS:
    - Drain body thickness: 3/4" to 1-1/4" (bonding flange type)
    - Grate width: 2" to 6"
    - Flow rate: 11-18 GPM (varies by length)
    - Min drain length for curbless: Full wall-to-wall
    - Brands: Schluter KERDI-LINE, Infinity Drain, QuARTz by ACO
```

### 2.4 Floor-to-Wall Transition in Wet Areas

```
    SECTION AT SHOWER WALL BASE:

    Wall tile
    |
    |  Thinset
    |  ________________________________
    |  KERDI membrane (wall)           |
    |  ________________________________|
    |  Cement board or KERDI-BOARD     |
    |  ________________________________|
    |  Stud wall                       |
    |__________________________________|
    |
    |  KERDI-BAND (5" wide)  <-------- Bridges wall-to-floor joint
    |  covers change of plane          Lapped 2" onto wall membrane
    |_________________________________  Lapped 2" onto floor membrane
    |  KERDI membrane (floor)          |
    |  ________________________________|
    |  Mortar bed / shower tray        |
    |__________________________________|

    CRITICAL REQUIREMENTS:
    - Never rely on caulk alone at floor-wall joint
    - Membrane must be continuous across the change of plane
    - KERDI-BAND or equivalent reinforcing strip at ALL corners
    - Inside corners: pre-formed KERDI-KERECK corner pieces
    - Sealant (KERDI-FIX) at final tile grout joints only
```

### 2.5 Grab Bar Blocking Requirements

```
    WALL SECTION WITH BLOCKING:

    Finished wall (tile, FRP, etc.)
    |
    |  Cement board / moisture barrier
    |  ________________________________
    |  2x6 or 2x8 blocking            | <-- Blocking MUST be installed
    |  (continuous, horizontal)        |     BEFORE wall finish
    |  between studs                   |
    |  ________________________________|     Blocking height zones:
    |  Studs at 16" o.c.              |     33"-36" AFF (grab bars)
    |__________________________________|     17"-19" AFF (tub bars)

    BLOCKING SPECIFICATIONS:
    - Material: 2x6 or 2x8 solid lumber (not OSB or plywood)
    - Orientation: Horizontal, flat between studs
    - Fastening: 3" screws or 16d nails, toenailed to studs
    - Width: 36" continuous minimum (full shower wall preferred)
    - Height zones:
      * Water closet (toilet): 33"-36" AFF
      * Shower/tub: 33"-36" AFF (horizontal bar)
      * Shower seat: 17"-19" AFF
      * Vertical bars: Full height from 33" to 6" above top of bar
    - BETTER PRACTICE: Install 3/4" plywood on full wall behind
      cement board for universal mounting flexibility
```

**ADA Grab Bar Placement Requirements (ADA 604.5, 608.3):**

```
    PLAN VIEW - WATER CLOSET:

                   SIDE WALL
    ______________|________________
   |              |                |
   |   42" bar    |                |
   |   (side wall)|                |
   |              |                |   REAR WALL
   |      WC      |       36" bar  |_______________
   |   (toilet)   |     (rear wall)|
   |              |                |
   |______________|________________|

   SIDE WALL BAR: 42" long, 12" max from rear wall, 54" from rear wall
   REAR WALL BAR: 36" long, centered on toilet (24" one side, 12" other)
   HEIGHT: 33"-36" AFF to top of gripping surface

    SECTION - SHOWER (TRANSFER TYPE):

    |  18" bar     |
    |  (vertical)  |
    |              |    Horizontal bars on
    |  ____________|    three walls
    | |            |    48" long on control wall
    | | 48" bar    |    (back wall and side wall
    | | (horiz)    |    per specific layout)
    | |____________|
    |              |
    |   SEAT       |
    |______________|

    BAR STRUCTURAL REQUIREMENTS:
    - Must resist 250 lbs at any point (vertical or horizontal force)
    - Diameter: 1-1/4" to 2" (circular cross-section)
    - Wall clearance: 1-1/2" between bar and wall
    - Clearance below/beside: 1-1/2" min to projecting objects
    - Clearance above: 12" min to projecting objects
    - Peened (slip-resistant) finish recommended for wet areas
```

### 2.6 Shower Glass Enclosure Mounting

```
    SECTION AT GLASS PANEL BASE (FIXED):

    Glass panel (3/8" or 1/2" tempered)
    |
    |   U-channel (aluminum or stainless)
    |   ________________________________
    |  |  Setting blocks (neoprene)     |
    |  |  at 1/4 points                 |
    |  |________________________________|
    |  Silicone sealant (both sides)
    |  ________________________________
    |  Curb cap tile
    |  ________________________________
    |  Shower curb (waterproofed)

    SECTION AT GLASS PANEL WALL (FIXED):

    |  Glass panel
    |  |
    |  |  U-channel (wall-mounted)
    |  |  ___________________________
    |  | |  Silicone sealant         |
    |  | |___________________________|
    |  |  Anchors into studs/blocking
    |__|
       Wall tile

    SPECIFICATIONS:
    - Glass: 3/8" (10mm) or 1/2" (12mm) tempered safety glass
    - U-channel: 1/2" or 5/8" deep (match glass thickness + setting clearance)
    - Setting blocks: 1/4" neoprene at bottom, 1/4 points from ends
    - Silicone: 100% silicone (GE Silicone II or Dow 795), mildew-resistant
    - Blocking: 2x6 or 2x8 at all mounting points in wall
    - Hardware mounting: Through-glass clamps need 1/2" glass minimum
    - Door hardware: Continuous hinge or pivot hinge (top/bottom)
```

### 2.7 Tub Surround Details

```
    SECTION AT TUB FLANGE:

    Wall tile
    |
    |  Thinset mortar
    |  ________________________________
    |  Cement board (1/2")             |
    |  ________________________________|
    |  Moisture barrier (felt paper    |
    |  or membrane)                    |
    |  ________________________________|
    |  Studs at 16" o.c.              |
    |__________________________________|
    |
    |  Cement board laps OVER tub flange
    |  (NOT behind it)
    |  ________________________________
    |  |  Tub flange (nailing flange) |
    |  |  Fastened to studs           |
    |__|______________________________|
       |                              |
       |  TUB BODY                    |
       |______________________________|

    CRITICAL RULES:
    - Cement board overlaps tub flange by 1/4"-1/2"
    - 1/8" gap between bottom of cement board and tub lip
    - Fill gap with silicone sealant (NOT grout)
    - Waterproof membrane behind cement board, extending
      into tub (lapping over flange)
    - Alternatively: KERDI membrane over cement board face
    - NEVER paper-face drywall behind tile in wet areas
```

### 2.8 Floor Drain Details

```
    SECTION THROUGH FLOOR DRAIN:

    Tile (flush with drain grate)
    Thinset
    ________________________________
    Mortar bed (sloped 1/4"/ft)
    ________________________________
    Waterproof membrane
    ________________________________    Drain body (cast iron or PVC)
    Pre-slope mortar             |     |
    _________________________   |_____|
    Subfloor                   |       |
    ___________________________| P-Trap|
    Floor joist                |_______|
                               |       |
                               | Waste |
                               | line  |

    DRAIN TYPES:
    - Center drain: Round, 2" or 3" outlet
    - Linear drain: Channel-type, wall-to-wall
    - Point drain: Square, often with tileable grate
    - Trench drain: Commercial, stainless steel

    CODE REQUIREMENTS:
    - 2" min waste line for shower (IPC 709.1)
    - 3" min waste line for floor drain (IPC 709.1)
    - P-trap required (IPC 1002.1)
    - Trap primer or trap seal required for infrequently used drains
    - Slope: 1/4" per foot minimum to drain (IPC 417.5.2)
```

---

## 3. STAIR & RAILING DETAILS

### 3.1 Stair Geometry Requirements

**IBC (Commercial) vs IRC (Residential) Comparison:**

| Dimension | IBC (Commercial) | IRC (Residential) |
|-----------|-------------------|---------------------|
| Max riser height | 7" (178mm) | 7-3/4" (196mm) |
| Min tread depth | 11" (279mm) | 10" (254mm) |
| Min width | 44" (>50 occ.) / 36" (<50 occ.) | 36" |
| Min headroom | 80" (6'-8") | 80" (6'-8") |
| Max nosing projection | 1-1/4" (32mm) | 1-1/4" (32mm) |
| Nosing radius | Max 9/16" (14mm) | Max 9/16" (14mm) |
| Landing depth | Min = stair width (max 48" required) | Min 36" |
| Max flight height | 12'-0" between landings | No limit (IRC) |
| Riser/tread uniformity | 3/8" max variation | 3/8" max variation |
| Winders | Not permitted in means of egress | Permitted with min 6" at walk line |
| Spiral stairs | Limited in means of egress | Min 26" clear width, 7-1/2" tread at 12" from narrow edge |

**Stair Geometry Formulas:**
- Standard rule: 2R + T = 24" to 25" (where R = rise, T = tread run)
- Comfort formula: R + T = 17" to 18"
- Safety formula: R x T = 70 to 75
- Common residential: 7-1/2" rise x 10" tread (typical 8' ceiling)
- Common commercial: 7" rise x 11" tread

### 3.2 Stringer Details

#### Wood Cut (Sawtooth) Stringer
```
    SECTION:

         ___|___
        |       |___|___
        |       |       |___|___
        |       |       |       |
        |       |       |       |    2x12 minimum (deeper for longer spans)
        |       |       |       |    Max notch depth: don't reduce below
        |       |       |       |    3-1/2" effective depth at any point
        |_______|_______|_______|

    SPECIFICATIONS:
    - Material: 2x12 (nom.) Southern Pine or Douglas Fir
    - Min remaining depth after notch: 3-1/2"
    - Fastening at top: Metal hanger (Simpson LSC) or ledger
    - Fastening at bottom: Metal angle bracket or kicker plate
    - Spacing: 16" o.c. max (12" o.c. for stone/tile treads)
    - Glue blocks at tread-riser joints (interior stairs)
```

#### Wood Closed (Housed) Stringer
```
    SECTION:

    |  _____________________________|
    | |  Routed groove (3/8"-1/2"   |    Treads and risers set into
    | |  deep) for tread            |    routed grooves in stringer
    | |_____________________________|
    | |  Routed groove for riser    |    Wedged and glued from behind
    | |_____________________________|
    |                               |    Used for finished stairs
    |_______________________________|    with visible stringers

    SPECIFICATIONS:
    - Material: 1-1/8" to 1-1/2" hardwood or softwood
    - Groove depth: 3/8" to 1/2"
    - Wedges: Hardwood, glued with PVA
    - Router template: Custom jig for consistency
```

#### Steel Stringer (C-Channel or Plate)
```
    SECTION (STEEL PLATE STRINGER):

         ___|___
        |       |___|___
        |       |       |___|___       3/8" or 1/2" steel plate
        |       |       |       |      Cut to sawtooth profile
        |       |       |       |
        |       |       |       |      Treads welded or bolted
        |       |       |       |      on top of stringer teeth
        |_______|_______|_______|

    SECTION (STEEL C-CHANNEL STRINGER):

    C10x15.3 or C12x20.7 channel
    Continuous, angled from floor to floor
    Clip angles welded at tread locations
    Treads span between two channels

    SPECIFICATIONS:
    - Plate stringer: 3/8" to 1/2" A36 steel plate
    - Channel stringer: C10 to C12 (depends on span and load)
    - HSS tube stringer: HSS 8x4x3/8 (modern/exposed)
    - Connection at top: Bolted to steel beam or embed plate
    - Connection at bottom: Base plate with anchor bolts
    - Fireproofing: Spray-on or intumescent coating if required
    - Finish: Prime + paint, powder coat, or hot-dip galvanize
    - Design load: 100 PSF live (300 lb concentrated), 40 PSF residential
```

#### Concrete Stringer (Cast-in-Place or Precast)
```
    SECTION:

    Formed concrete stair with integral risers and treads
    ________________________________
    |  |  |  |  |  |  |  |  |  |  |
    |  |__|  |__|  |__|  |__|  |  |    Min slab thickness: 5" to 8"
    |     |     |     |     |  |  |    Reinforcement: #4 @ 12" o.c.
    |     |     |     |     |  |  |    both ways (minimum)
    |     |     |     |     |  |  |
    |     |     |     |     |__|__|    Nosing cast integral or
    |     |     |     |              applied (metal or rubber)
    |     |     |_____|
    |     |_____|
    |_____|

    SPECIFICATIONS:
    - Concrete: 3000-4000 PSI (f'c)
    - Min slab thickness: 5" (residential), 6"-8" (commercial)
    - Reinforcement: #4 or #5 bars, 12" o.c. each way
    - Top bars: Extend into landings min 12" past face of support
    - Bottom bars: Hook into landing/support
    - Nosing: Cast-in metal nosing or applied rubber/aluminum
    - Finish: Broom finish, formed finish, or applied finish (stone, tile, carpet)
    - Formwork: Plywood + dimensional lumber, stripped at 7 days min
```

### 3.3 Tread/Riser Connection Details

```
    WOOD STAIR TREAD/RISER CONNECTIONS:

    OPTION A: Dado Joint              OPTION B: Rabbet Joint
    _____________                     _____________
   |  Tread      |                   |  Tread      |
   |  (1" thick) |                   |  (1" thick) |
   |_______|_____|                   |_______      |
           |                                 |     |
           | Riser                           |Riser|
           | (3/4" thick)                    |     |
           | set into                        | laps|
           | 1/4" dado                       |     |
           | in tread                        |_____|

    OPTION C: Butt Joint + Glue Block
    _____________
   |  Tread      |
   |_____________|
   |    / Glue   |     Triangular glue block
   |   /  block  |     (1-1/2" x 1-1/2")
   |  /__________|     glued and screwed behind
   |             |
   | Riser       |
   |_____________|

    OPEN RISER STAIRS:
    - No riser (tread only)
    - IBC: Opening must not allow 4" sphere to pass (commercial)
    - IRC: 4-3/8" max opening for risers > 30" above grade
    - Tread thickness: 1-1/2" min (2x material) for open risers
    - Support: Steel brackets, wood cleats, or cable/rod infill
```

### 3.4 Nosing Profiles

```
    STANDARD NOSING PROFILES:

    PENCIL ROUND:        FULL BULLNOSE:       SQUARE (EASED):
    ___________          ___________           ___________
   |    _      |        |   ___    |          |  |        |
   |   / |     |        |  /   \   |          |  |        |
   |  |  |     |        | |     |  |          |__|        |
   |  |  |     |        | |     |  |

    1/4" radius          1/2" radius           1/16" ease
    Most common          ADA-friendly           Modern/commercial

    BEVELED:             STAIR NOSE (APPLIED):
    ___________          ___________
   | \         |        |  ___     |
   |  \        |        | /   \    |   Applied metal or rubber nosing
   |   \       |        ||     |   |   Screwed or adhesive-set
   |    |      |        ||     |   |   Typical for concrete or retrofit

    NOSING CODE REQUIREMENTS (IBC 1011.5.5):
    - Projection: 3/4" min, 1-1/4" max beyond tread below
    - Radius: Max 9/16" at leading edge
    - Beveling: Max 1/2" (60-degree max from horizontal)
    - Uniformity: Max 3/16" variation between adjacent nosings
    - Solid risers required if 30" or more above floor below
    - Contrast strip: Recommended for accessibility (not code-required in all jurisdictions)
```

### 3.5 Guardrail & Handrail Requirements

```
    GUARDRAIL SECTION:

    IBC (Commercial):                    IRC (Residential):

    |--- Top rail ---| 42" min          |--- Top rail ---| 36" min
    |                |                   |                |
    |  Balusters     |                   |  Balusters     |
    |  4" sphere     |                   |  4" sphere     |
    |  cannot pass   |                   |  cannot pass   |
    |                |                   |                |
    |  6" triangle   |                   |                |
    |  at tread/riser|                   |                |
    |________________|                   |________________|
        Tread                                Tread

    GUARDRAIL REQUIREMENTS:
    - Height: 42" min (IBC commercial), 36" min (IRC residential)
    - Measured vertically from leading edge of tread nosing
    - At landings: Measured from landing surface
    - Baluster spacing: 4" max clear (sphere test)
    - Bottom rail: 4" max above tread nosing (sphere test)
    - Triangular opening at tread: 6" sphere max (IBC)
    - Structural: 200 lb point load at any point, any direction
    - Concentrated load: 50 PLF along top rail
    - Infill load: 25 PSF on infill area
    - Glass guards: Laminated glass required (IBC 2407)
```

```
    HANDRAIL SECTION:

    GRASPABLE PROFILES:

    TYPE I (Circular):        TYPE II (Non-Circular):

        ___                       ___________
       /   \                     |     ___   |
      |  O  |  1-1/4" to 2"     |    |   |  |  Perimeter: 4" min, 6-1/4" max
       \___/   outside dia.     |    |___|  |  Cross-section: 2-1/4" max
                                |___________|  Graspable finger recess:
                                               min 1/2" deep on both sides

    HANDRAIL REQUIREMENTS:
    - Height: 34" to 38" above tread nosing (measured at leading edge)
    - Wall clearance: 1-1/2" minimum
    - Continuity: Full length of flight
    - Extensions: 12" horizontal at top of flight
                  Sloped full tread depth + 12" horizontal at bottom
    - Returns: Ends must return to wall, post, or floor
    - Intermediate rail: Required if stair width > 60" (IBC)
    - Mounting: Must resist 200 lb concentrated load
    - Both sides required if stair width > 44"
```

### 3.6 Baluster Details

```
    BALUSTER TYPES:

    WOOD:                    METAL:                  CABLE:
    1-1/4" to 1-3/4"       5/8" to 3/4" round      3/16" to 1/4" dia.
    square or turned        bar or 1" square tube    stainless steel
    ___                     ___                      ___
   |   |                   | . |                    |---|
   |   |                   | . |                    |---|
   |   |                   | . |                    |---|  3" max spacing
   |   |                   | . |                    |---|  between cables
   |___|                   |_._|                    |---|  (4" sphere test)

    SPACING REQUIREMENTS:
    - 4" sphere cannot pass between balusters (IBC 1015.4)
    - At stair tread: 6" sphere cannot pass triangular opening
      formed by tread, riser, and bottom rail
    - Typical baluster spacing: 3-3/4" to 3-7/8" clear
      (to account for baluster width and achieve < 4" opening)
    - Cable railing: Cables at 3" o.c. max (3" spacing + cable dia. < 4")
    - Horizontal cables/rails: Check local jurisdiction
      (some restrict horizontal elements as "ladder effect")
```

---

## 4. CEILING DETAILS

### 4.1 ACT (Acoustical Ceiling Tile) Grid System

```
    REFLECTED CEILING PLAN:

    Wall Angle
    |___________________________________________________|
    |  |     |     |     |     |     |     |     |  |    |
    |  | 2x4 | 2x4 | 2x4 | 2x4 | 2x4 | 2x4 |  |    |
    |  | tile | tile | tile | tile | tile | tile |  |    |  Main Tee
    |  |_____|_____|_____|_____|_____|_____|  |<---|   (4' o.c.)
    |  |     |     |     |     |     |     |  |    |
    |  | 2x4 | 2x4 | 2x4 | 2x4 | 2x4 | 2x4 |  |    |
    |  |_____|_____|_____|_____|_____|_____|  |    |    Cross Tee
    |  |     |     |     |     |     |     |  |    |    (2' o.c.)
    |  | 2x4 |                               |    |
    |__|_____|_________________________________|____|

    Wall Angle (continuous perimeter)
```

#### ACT Grid Component Details
```
    SECTION THROUGH SUSPENDED CEILING:

    Structure above (deck, joist, etc.)
    |
    |  Hanger wire (12 ga. min)         <-- 4'-0" o.c. along main tee
    |  |                                     First wire within 24" of wall
    |  |  3 tight turns in 3" at top
    |  |
    |  |  Main Tee (1-1/2" or 15/16" face)
    |  |  __________________________________
    |  |_|  |          |          |         |
    |     |  | Cross   | Cross   | Cross   |    Cross tees at 2' o.c.
    |     |  | Tee     | Tee     | Tee     |    (for 2x4 tiles)
    |     |__|_________|_________|_________|    or 4' o.c. (for 2x2 tiles)
    |        |  ACT    |  ACT    |  ACT    |
    |        |  tile   |  tile   |  tile   |
    |        |_________|_________|_________|

    Wall Angle
    ______________
    |            |    7/8" x 7/8" or 1" x 1" L-angle
    |            |    Fastened to wall at 24" o.c.
    |____________|    Level to grid height

    SPECIFICATIONS:
    - Main tee spacing: 4'-0" o.c.
    - Cross tee spacing: 2'-0" o.c. (2x4 tile) or 4'-0" o.c. (2x2 tile)
    - Hanger wire: 12 gauge galvanized (min), 4'-0" o.c. along main tees
    - First hanger: Max 24" from wall
    - Wire attachment: 3 tight turns in 3" minimum
    - Main tee to wall clearance: 3/4" (3/8" min, 3/4" max)
    - Grid face width: 15/16" (standard) or 9/16" (narrow/slimline)
    - Plenum depth: 6" minimum above grid (varies by MEP coordination)
    - Tile sizes: 24"x24" or 24"x48" (most common)
    - Tile types: Lay-in (drops into grid), tegular (rabbeted edge, sits below grid)
    - NRC rating: 0.50-0.90 (higher = more sound absorption)
    - CAC rating: 35-44 (higher = more sound blocking between rooms)
```

#### Seismic Bracing (Where Required)
```
    SECTION SHOWING SEISMIC WIRE:

    Structure
    |
    |  Splay wire (45 degrees)     <-- 12' o.c. max in both directions
    |  \                                Provides lateral bracing
    |   \
    |    \ 12 ga. wire
    |     \
    |      Main tee
    |______|_________________________

    SEISMIC REQUIREMENTS (ASCE 7, IBC):
    - Seismic Design Category C and above
    - Splay wires at 45 degrees, 12' o.c. each direction
    - Perimeter compression posts at walls
    - Heavy fixtures independently supported
    - 2" perimeter clearance (free-floating system)
    - Seismic clips on cross tees to main tees
```

### 4.2 Drywall Ceiling Details

#### Standard Drywall Ceiling Framing
```
    SECTION:

    Structure above
    |
    |  Hanger wire or clip
    |  |
    |  |  1-1/2" carrying channel (hat channel)
    |  |  at 4'-0" o.c. (perpendicular to furring)
    |  |  ___________________________________
    |  |_|                                   |
    |     |  7/8" furring channel             |    16" o.c. (1/2" drywall)
    |     |  _____|_______|_______|_____     |    or 24" o.c. (5/8" drywall)
    |     |_|     |       |       |     |    |
    |       |  5/8" Type X gypsum board |    |
    |       |_____|_______|_______|_____|    |
    |                                        |

    SPECIFICATIONS:
    - Carrying channel: 1-1/2" cold-rolled (min 16 ga.)
    - Furring channel: 7/8" hat channel (min 25 ga.)
    - Carrying channel spacing: 4'-0" o.c. max
    - Furring channel spacing: 16" o.c. (1/2" board), 24" o.c. (5/8" board)
    - Hanger wire: 8 ga. to 12 ga. depending on load
    - Gypsum board: 1/2" (standard), 5/8" (fire-rated, UL listed)
    - Screws: #6 x 1-1/4" (1/2" board), #6 x 1-5/8" (5/8" board)
    - Screw spacing: 12" o.c. max at all framing members
```

#### Drywall Ceiling to ACT Transition
```
    SECTION AT TRANSITION:

    |  Drywall ceiling          |  ACT ceiling
    |  (higher or lower)        |
    |  _________________________|
    |  |  5/8" gypsum board     |     Transition trim
    |  |  ______________________|     (USG DWS, Flannery ACTD)
    |  | |                      |___________________________________
    |  | | Furring/framing      |  |  Main tee  | Cross | ACT tile |
    |  | |                      |  |____________|_tee___|__________|
    |__|_|                      |__|
       |  Soffit framing        |  |  Grid hanger
       |  (studs or channel)    |  |

    TRANSITION OPTIONS:
    - USG DWSS (Drywall to Suspended System): Two-piece aluminum trim
    - Flannery ACTD: Hook-on trim, drywall adapter + ACT transition
    - Custom: Aluminum angle with reveals
    - Shadow reveal: 1/2" to 3/4" gap at transition (modern)
```

### 4.3 Soffit & Bulkhead Construction

```
    SECTION THROUGH SOFFIT (ABOVE CABINETS):

    Ceiling (structure above)
    |
    |  Top track (floor runner)
    |  ________________________________
    |  |  Studs at 16"-24" o.c.        |
    |  |  (25 ga. steel or 2x4 wood)   |   Soffit depth: 12"-18" typical
    |  |  ________________________________|   Width: Flush with upper cabinets (12")
    |  |  |  Bottom track               |     or deeper (to conceal ductwork)
    |  |  |  ___________________________|
    |  |  | |  5/8" gypsum board        |
    |  |  | |  (finish all exposed      |
    |  |  | |   faces)                  |
    |__|__|_|___________________________|
       |     |
       |     |  Upper cabinet below
       |     |

    FRAMING OPTIONS:
    A. Steel stud soffit:
       - Top track screwed to ceiling framing/structure
       - Bottom track for gypsum board attachment
       - 25 ga. steel studs at 16"-24" o.c.
       - 1-5/8" or 2-1/2" studs for narrow soffits
       - 3-5/8" studs for soffits requiring MEP space

    B. Wood framed soffit:
       - 2x4 or 2x3 ladder framing
       - Horizontal members screwed to ceiling joists
       - Vertical drops at face
       - Cross members at 16" o.c.

    C. Drywall L-bracket (small soffits):
       - Metal angle brackets at 16" o.c.
       - Gypsum board screwed to brackets
       - For soffits 6" or less in depth
```

### 4.4 Light Cove Details

```
    SECTION THROUGH LIGHT COVE (WALL-MOUNTED):

    Ceiling
    _________________________________
    |
    |  2"-6" from ceiling
    |  (more distance = more uniform light wash)
    |
    |  LED strip (facing up)
    |  ___
    | |   |  Aluminum LED channel
    | |___|  (with diffuser lens)
    |  ___________________________________
    | |                                   |
    | |  Cove fascia (gypsum board,       |  6"-8" projection from wall
    | |  wood, or metal)                  |  Top of fascia level with
    | |  4"-8" tall                       |  or below LED strip
    | |___________________________________|
    |
    WALL

    SECTION THROUGH LIGHT COVE (CEILING-MOUNTED):

    Ceiling
    _____|     |_____|     |_____
         |     |     |     |
         | LED | gap | LED |        Recessed cove in soffit/ceiling
         |strip| 2"  |strip|        Symmetrical or asymmetrical
         |     |     |     |
    _____|     |_____|     |_____

    Drywall ceiling below

    KEY DIMENSIONS:
    - LED to ceiling: 2"-6" (closer = hot spots, farther = uniform wash)
    - LED to fascia face: 2"-4" (must hide LED from view at standing eye height)
    - Fascia projection: 6"-8" from wall
    - Fascia height: 4"-8"
    - Top of fascia: Level with or 1" below LED source
    - Cove interior: Paint flat white (reflective surface)
    - LED output: Min 100 lm/W efficiency
    - Color temperature: 2700K (warm), 3000K (neutral), 3500K (commercial)
    - CRI: 90+ recommended for architectural lighting
    - Power supply: Remote driver, 24V DC preferred
    - LED strip width: 8mm, 10mm, or 12mm (match channel)
```

### 4.5 Access Panel Details

```
    SECTION THROUGH ACCESS PANEL:

    |  Gypsum board ceiling
    |  ________________________________
    |  |                              |
    |  |   ACCESS PANEL               |
    |  |   (flush with ceiling)       |    Standard sizes:
    |  |                              |    12"x12", 16"x16", 24"x24",
    |  |   Concealed hinge            |    24"x36", 24"x48"
    |  |   or lift-out panel          |
    |  |______________________________|
    |  ________________________________
    |  |  Frame (drywall bead type)   |    Frame flush with ceiling plane
    |  |  or surface-mount frame      |    Recessed for drywall taping
    |  |______________________________|

    TYPES:
    - Flush (drywall bead): Frame accepts drywall compound, invisible when closed
    - Surface-mount: Visible frame, painted to match
    - Fire-rated: UL classified (1-hr or 2-hr), self-closing, with fusible link
    - Insulated: For exterior or conditioned/unconditioned boundary
    - Locking: Keyed, screwdriver, or Allen key

    MANUFACTURERS: Karp, Milcor, JL Industries, Babcock-Davis

    SPECIFICATIONS:
    - Frame: 16 ga. steel (standard), stainless steel (wet areas)
    - Door: 16-20 ga. steel with insulation (fire-rated)
    - Hinge: Concealed or piano hinge (fire-rated: spring-loaded)
    - Latch: Screwdriver operated (standard), cylinder lock (secure areas)
    - Fire-rated panels: Must match wall/ceiling assembly rating
```

### 4.6 Ceiling-to-Wall Intersection

```
    OPTION A: STANDARD (No Reveal):

    |  Gypsum board ceiling
    |  ___________________________
    |  |                         |
    |__|                         |    Inside corner joint
       |                         |    Paper tape + 3 coats compound
       |  Wall (gypsum board)    |    OR caulk at drywall-to-drywall
       |                         |
       |                         |

    OPTION B: SHADOW REVEAL (Modern):

    |  Gypsum board ceiling
    |  ___________________________
    |  |                         |
    |  |   1/2"-3/4" gap         |    Shadow channel trim
    |  |   _____                 |    (Fry Reglet, Trim-Tex, Gordon)
    |  |  |     |                |    Creates clean shadow line
    |  |  |     |                |    at wall-ceiling intersection
    |__|__|     |________________|
       |                         |
       |  Wall                   |
       |                         |

    OPTION C: CROWN MOULDING:

    |  Ceiling
    |  ___________________________
    |  |     ____                |
    |  |    /    \               |    Crown moulding sizes:
    |  |   /      \              |    2-1/4", 3-1/4", 4-1/2", 5-1/4"
    |  |  /        \             |    Spring angle: 38/52 or 45/45
    |__|_/          \____________|
       |                         |
       |  Wall                   |

    OPTION D: ACT TO WALL:

    |  ACT tile
    |  ___________________________
    |  |  Wall angle             |    7/8" x 7/8" L-angle
    |__|__|______________________|    Fastened to wall at 24" o.c.
       |                         |    Tile rests on wall angle
       |  Wall                   |    1/4" gap behind tile for expansion
       |                         |
```

---

## 5. FLOOR TRANSITION DETAILS

### 5.1 Tile-to-Carpet Transition

```
    SECTION:

    Carpet                               Tile
    ___________                          ___________
    |          |                        |           |
    | Pad      |   Tack strip          | Thinset   |
    | (3/8")   |   (1/4" high)         | (1/8")    |
    |__________|___|___________________|___________|
                   |   Reducer strip   |
                   |   (metal/wood)    |            Cement board or
    _______________| __________________|            plywood underlayment
    |                                              |
    |              SUBFLOOR                        |
    |______________________________________________|

    TRANSITION TYPES:
    - Metal reducer: Aluminum, brass, or stainless steel; Z-bar profile
    - Wood reducer: Hardwood T-molding or reducer
    - Schluter RENO-T: Stainless steel or aluminum, set in thinset under tile
    - Carpet tack strip: Set 1/4"-3/8" from tile edge
    - Height difference: Typically 0"-1/4" (carpet + pad vs. tile + thinset)
```

### 5.2 Tile-to-Wood Transition

```
    SECTION:

    Hardwood (3/4")                     Tile (3/8")
    ___________                         ___________
    |          |                       |           |
    | Adhesive |    T-Molding          | Thinset   |
    | or nails |    or Reducer         | (1/8")    |
    |__________|____|__________________|___________|
                    |                  |
    ________________|  Cement board    |
    |               |  (1/4"-1/2")    |
    | Plywood       |_________________|
    | underlayment  |                 |
    |_______________|_________________|
    |                                 |
    |           SUBFLOOR              |
    |_________________________________|

    TRANSITION OPTIONS:
    - T-Molding: Equal height floors, snaps into metal track
    - Reducer: Tile higher, tapers down to wood
    - Flat bar: Minimal height difference, decorative metal
    - Schluter RENO-T: Tile side embedded in thinset
    - Flush transition (best): Adjust underlayment thickness
      so both finishes end at same height

    HEIGHT CALCULATIONS:
    - 3/4" hardwood + 3/4" plywood = 1-1/2" total
    - 3/8" tile + 1/8" thinset + 1/2" cement board + 1/2" plywood = 1-1/2" total
    - With DITRA: 3/8" tile + 1/8" thinset + 1/8" DITRA + 3/4" plywood = 1-3/8"
```

### 5.3 Slab Depression for Thick-Set Tile

```
    SECTION THROUGH SLAB DEPRESSION:

    Adjacent floor finish          Tile floor finish
    (carpet, wood, etc.)           (stone, thick-set tile)
    ___________                    ___________
    |          |                  |           |  Tile (1/2"-3/4")
    | Finish   |                  | Mortar    |  Mortar bed (3/4"-1-1/2")
    | material |                  | bed       |  Waterproof membrane
    |__________|                  |___________|  (if wet area)
    |          |                  |           |
    | Concrete |   Step in slab   | Depressed |
    | slab     |   ______________|  concrete  |
    | (typ.)   |  |              |  slab      |
    |          |  |              |            |
    |__________|__|______________|____________|

    DEPRESSION DEPTHS:
    - Ceramic tile (thinset): 3/4" depression
    - Porcelain tile (thinset): 3/4" depression
    - Natural stone (thinset): 1" depression (thicker tile)
    - Thick-set mortar bed: 1-1/2" to 2" depression
    - Stone on mortar bed: 2" to 2-1/2" depression
    - Terrazzo: 1-1/2" to 2" depression

    STRUCTURAL NOTES:
    - Depressions must be shown on structural drawings
    - Reinforcement must be maintained through depression
    - Step in slab typically formed with steel angle or wood form
    - Waterproofing at depression-to-slab step (if wet area)
    - Coordinate depression depth with finish schedule early
    - Depressed slabs increase slab thickness locally
```

### 5.4 Expansion Joint Covers

```
    SECTION THROUGH FLOOR EXPANSION JOINT:

    Floor finish          Joint cover          Floor finish
    ___________          ___________          ___________
    |          |        |  Cover   |         |          |
    |  Tile    |        |  plate   |         |  Tile    |
    |__________|________|__________|_________|__________|
    |          |  Joint |   Joint  | Joint   |          |
    | Slab     |  filler| movement | filler  | Slab     |
    |          | (comp.)| gap      | (comp.) |          |
    |__________|________|__________|_________|__________|

    JOINT TYPES:
    - Surface-mount: Metal cover plate screwed to one side
    - Flush: Recessed frame with removable cover
    - Seismic: Bellows or sliding plate for large movement
    - Fire-rated: Intumescent seal within joint, rated assembly

    MOVEMENT RANGES:
    - Standard: +/- 25% of joint width
    - Seismic: +/- 50% or more
    - Typical joint width: 1" to 4"

    MANUFACTURERS: Balco, CS Group, Nystrom, Construction Specialties
```

### 5.5 Floor Penetration Details

```
    SECTION THROUGH PIPE PENETRATION:

    Floor finish (tile)
    _____|     |_____
         |     |          Escutcheon plate (split ring)
    _____|     |_____     covers gap between pipe and tile
    |    |     |    |
    | Thinset  |    |     1/2" to 1" annular gap around pipe
    |____|     |____|     filled with:
    |    |     |    |     - Sealant (non-fire-rated)
    | Slab| Pipe|   |     - Firestop (if fire-rated assembly)
    |    |     |    |
    |____|_____|____|

    DETAIL REQUIREMENTS:
    - Non-rated floor: Silicone sealant around pipe, escutcheon cover
    - Fire-rated floor: UL-listed firestop system required
    - Plumbing penetrations: Floor flange or escutcheon
    - Electrical penetrations: Conduit sleeve, caulk or putty pad
    - Max annular space: Per firestop system listing
    - Escutcheon types: Split ring (retrofit), one-piece (new construction)
```

---

## 6. FIRE-RATED ASSEMBLY DETAILS

### 6.1 UL Assembly Designations

**Common UL Wall/Partition Designs:**

| UL Design | Rating | Construction | Common Use |
|-----------|--------|--------------|------------|
| **U465** | 1-hr | 1 layer 5/8" Type X each side, 3-5/8" studs 24" o.c. | Standard 1-hr interior partition |
| **U411** | 1-hr | 1 layer 5/8" Type X each side, 2-1/2" studs 24" o.c. | Minimum 1-hr partition |
| **V438** | 1-4 hr | Multiple layers Type X, 25 ga. studs 24" o.c. | Versatile multi-hour rating |
| **U419/W419** | 1-4 hr | Shaft wall (C-H stud system, liner panels) | Elevator/mechanical shafts |
| **U305** | 2-hr | 2 layers 5/8" Type X each side, 3-5/8" studs 24" o.c. | 2-hr corridor/separation wall |
| **U339** | 2-hr | 2 layers 5/8" Type X each side, 6" studs 24" o.c. | 2-hr with larger cavity |
| **V488** | 1-2 hr | Chase wall (double stud row) | Plumbing/utility chases |

**Common UL Floor/Ceiling Designs:**

| UL Design | Rating | Construction | Common Use |
|-----------|--------|--------------|------------|
| **D916** | 1-hr | Steel joists, 1 layer 5/8" Type X ceiling, concrete topping | Steel frame floor |
| **G514** | 1-hr | Wood joists, 1 layer 5/8" Type X ceiling, plywood subfloor | Wood frame floor |
| **G516** | 2-hr | Wood trusses, 2 layers 5/8" Type X ceiling | Wood truss floor |
| **D501** | 2-hr | Steel deck, spray-applied fireproofing, concrete | Steel frame commercial |

### 6.2 1-Hour Rated Partition (UL U465)

```
    SECTION:

    1 Layer 5/8" Type X      1 Layer 5/8" Type X
    Gypsum Board             Gypsum Board
    |                                            |
    |  _________________________________________  |
    |  |                                       |  |
    |  |  3-5/8" Steel Studs                   |  |
    |  |  25 ga. min, 24" o.c.                 |  |
    |  |  (or 20 ga. for load-bearing)         |  |
    |  |                                       |  |
    |  |  Top & bottom track: 25 ga. min       |  |
    |  |                                       |  |
    |  |_______________________________________|  |
    |                                            |
    |____________________________________________|

    CRITICAL REQUIREMENTS:
    - Gypsum board: 5/8" Type X (fire-rated), UL classified
    - Board joints: Staggered 24" min between sides
    - Board joints on studs (no floating joints)
    - Screws: #6 x 1" Type S, 12" o.c. at edges, 12" o.c. field
    - All joints taped and finished (Level 2 min)
    - Acoustic sealant at top track, bottom track, and all perimeter
    - Electrical boxes: Min 24" horizontal separation between sides
    - Electrical boxes: Steel boxes only (no plastic in fire-rated walls)
    - Max box area: 16 sq. in. per 100 sq. ft. of wall (each side)
    - Insulation: Mineral wool or fiberglass (optional, improves STC)
```

### 6.3 2-Hour Rated Partition (UL U305)

```
    SECTION:

    2 Layers 5/8" Type X     2 Layers 5/8" Type X
    Gypsum Board              Gypsum Board
    |                                              |
    |  ___________________________________________  |
    |  |  Base layer: 5/8" Type X                |  |
    |  |  Screws: #6 x 1", 24" o.c.             |  |
    |  |  Joints staggered from face layer       |  |
    |  |                                         |  |
    |  |  3-5/8" Steel Studs                     |  |
    |  |  25 ga. min, 24" o.c.                   |  |
    |  |                                         |  |
    |  |_________________________________________|  |
    |  |  Face layer: 5/8" Type X                |  |
    |  |  Screws: #6 x 1-5/8", 12" o.c.         |  |
    |  |  Joints staggered from base layer       |  |
    |  |_________________________________________|  |
    |                                              |
    |______________________________________________|

    ADDITIONAL REQUIREMENTS:
    - All base layer joints staggered min 12" from face layer joints
    - Both sides identical construction
    - Screws must penetrate studs min 3/8"
    - Base layer attached first, then face layer through base
    - Outlet box limitations more restrictive than 1-hr
    - Putty pads required on all boxes (both sides)
    - Min 24" horizontal separation of boxes between sides
```

### 6.4 Shaft Wall Construction (UL U419/W419)

```
    SECTION:

    SHAFT SIDE:                           ROOM SIDE:

    1" Shaft Liner Panel    |  1 Layer 5/8" Type X
    (Type X, UL classified) |  Gypsum Board
    ________________________|____________________________
    |                       |                            |
    |  C-H Stud System:    |                            |
    |  2-1/2" C-studs      |  3-5/8" to 6" cavity      |
    |  nested in H-studs   |  (sound batt optional)     |
    |  at 24" o.c.         |                            |
    |                       |                            |
    |  J-track at top      |                            |
    |  and bottom          |                            |
    |_______________________|____________________________|

    KEY ADVANTAGE: Assembled entirely from one side (room side)
    - H-studs slide onto J-track, then liner panels slide into H-stud flanges
    - No access to shaft side required after initial framing

    SPECIFICATIONS:
    - Shaft liner: 1" Type X gypsum board (UL classified, e.g., USG Shaftliner)
    - C-H studs: 2-1/2" (USG CH-25, ClarkDietrich SL-25)
    - J-track: 2" (at floor and ceiling)
    - Room-side board: 5/8" Type X minimum (1 or 2 layers per rating)
    - Ratings: 1-hr to 4-hr (varies by layer count and configuration)
    - STC: 40-56 (varies by insulation and layers)
```

### 6.5 Head-of-Wall Details at Rated Assemblies

```
    SECTION AT HEAD OF WALL (FIRE-RATED):

    Structure above (concrete deck, steel deck + concrete)
    ________________________________________________________
    |                                                      |
    |  Fire-rated sealant or mineral wool + sealant        |
    |  (per UL system - typically 3/4" to 1" gap)          |
    |  ___________________________________________________  |
    |  |  Deflection track (slotted)                     |  |
    |  |  or deep leg track (2" legs)                    |  |
    |  |  with intumescent strip                         |  |
    |  |_________________________________________________|  |
    |                                                      |
    |  Gypsum board extends into gap                       |
    |  (continuous to structure or cut tight)               |
    |  ___________________________________________________  |
    |  |                                                 |  |
    |  |  Studs (top not fastened to track if              |  |
    |  |  deflection joint, or fastened with               |  |
    |  |  clip allowing vertical movement)                |  |
    |  |_________________________________________________|  |

    DEFLECTION JOINT OPTIONS:

    A. DEEP LEG TRACK:
       - 2" leg track (vs standard 1-1/4")
       - Stud nests inside track with gap at top
       - Allows +/- 3/4" to 1" vertical movement
       - Intumescent strip on track flanges (USG Fire Stop Tape)

    B. SLOTTED DEFLECTION TRACK:
       - Vertical slots in track web
       - Screws through slots allow vertical movement
       - Firestopping material in gap per UL system

    C. CLIP SYSTEM:
       - Proprietary clips (ClarkDietrich Slide Clip, USG Flex-C)
       - Clips mount to structure, stud slides vertically
       - Gypsum board cut 1" short of structure, sealed

    CRITICAL REQUIREMENTS:
    - Gap: 3/4" to 1" nominal (per UL system)
    - Movement: Up to 2" vertical deflection
    - Firestopping: UL-listed system (mineral wool + sealant, or intumescent)
    - Gypsum board: Must extend to within 1" of structure (per most UL systems)
    - Smoke seal: Continuous bead of fire-rated sealant at perimeter
    - Testing: ASTM E119 (fire resistance) + ASTM E1966 (head-of-wall)
```

### 6.6 Firestopping at Penetrations

```
    SECTION THROUGH FIRE-RATED WALL (PIPE PENETRATION):

    |  Gypsum board                                Gypsum board  |
    |  ________________                    ________________      |
    |  |              |                   |                |     |
    |  |   Steel      |    ___________    |   Steel        |     |
    |  |   sleeve     |   |           |   |   sleeve       |     |
    |  |   (optional) |   |  Pipe     |   |   (optional)   |     |
    |  |              |   |___________|   |                |     |
    |  |              |                   |                |     |
    |  |  Firestop    |   Annular space   |  Firestop      |     |
    |  |  material    |   filled with     |  material      |     |
    |  |  (caulk,     |   firestop        |  (caulk,       |     |
    |  |  putty, or   |   per UL system   |  putty, or     |     |
    |  |  wrap strip) |                   |  wrap strip)   |     |
    |  |______________|                   |________________|     |
    |                                                            |

    FIRESTOP SYSTEM RATINGS:
    - F Rating: Time fire is prevented from passing through
    - T Rating: Time temperature stays below 325F above ambient
    - L Rating: Air leakage rate (CFM) - important for smoke protection

    PENETRATION TYPES AND SOLUTIONS:

    | Penetrant | Firestop Method | UL Test Standard |
    |-----------|-----------------|------------------|
    | Metal pipe (steel, copper) | Caulk sealant | ASTM E814 / UL 1479 |
    | Plastic pipe (PVC, CPVC, ABS) | Intumescent wrap strip + caulk | ASTM E814 / UL 1479 |
    | Insulated pipe | Mineral wool packing + caulk | ASTM E814 / UL 1479 |
    | Electrical conduit (EMT, rigid) | Caulk sealant | ASTM E814 / UL 1479 |
    | Cable/wire bundle | Firestop putty or caulk | ASTM E814 / UL 1479 |
    | Cable tray | Pillow or block system | ASTM E814 / UL 1479 |
    | HVAC duct | Fire damper + sealant | ASTM E119 / UL 555 |
    | Blank opening | Mineral wool + sealant | ASTM E814 / UL 1479 |

    CRITICAL REQUIREMENTS:
    - Must use UL-listed system (not just any sealant)
    - System must match wall/floor rating (1-hr wall = 1-hr firestop)
    - Annular space per listing (typically 1/2" to 1" around pipe)
    - Plastic pipes: Intumescent material REQUIRED (pipe melts, intumescent closes gap)
    - Angle of penetration: 90 degrees (perpendicular) unless system is listed for angled
    - Max angled penetration: 45 degrees from perpendicular (if listed)
    - Inspection: All firestop installations subject to special inspection

    MAJOR FIRESTOP MANUFACTURERS:
    - 3M Fire Protection Products
    - Hilti Firestop
    - STI (Specified Technologies Inc.)
    - Tremco/Rectorseal
    - Nelson Firestop (now Emerson)
```

### 6.7 Fire-Rated Joint Systems

```
    SECTION AT RATED WALL TO RATED WALL (CORNER):

    OPTION A: CONTINUOUS BOARD:
    |  Board wraps corner
    |  ___________________________
    |  |                         |
    |  |  Wall A                 |___________________________
    |  |                         |                           |
    |  |                         |  Wall B                   |
    |  |_________________________|                           |
    |                            |                           |
    |                            |___________________________|

    OPTION B: BUTT JOINT WITH BLOCKING:
    |
    |  ___________________________
    |  |  Wall A                 |
    |  |                    _____|____________________________
    |  |                   |     |  Steel angle or stud at   |
    |  |                   |     |  corner for board support |
    |  |___________________|     |  Wall B                   |
    |                      |     |                           |
    |                      |_____|___________________________|

    REQUIREMENTS:
    - Board must be supported at all edges in fire-rated assemblies
    - Floating corners NOT permitted in rated walls
    - Steel angle or extra stud at corner for edge support
    - Fire-rated sealant at all joints
    - Joints between rated and non-rated walls: Sealant + rated board laps
```

### 6.8 Fire Damper Details

```
    SECTION THROUGH RATED WALL (DUCT PENETRATION):

    |  Gypsum board                              Gypsum board  |
    |  ________________    ______________    ________________  |
    |  |              |   |              |  |                | |
    |  |              |   | DUCTWORK     |  |                | |
    |  |  Steel stud  |   |              |  |  Steel stud    | |
    |  |  framing     |   | FIRE DAMPER  |  |  framing       | |
    |  |              |   | (in sleeve)  |  |                | |
    |  |              |   |______________|  |                | |
    |  |______________|                     |________________| |

    FIRE DAMPER REQUIREMENTS:
    - Required at all duct penetrations of fire-rated barriers (IBC 717)
    - Damper rating must match wall/floor rating (1-hr or 2-hr)
    - Sleeve: 16 ga. min steel, extends through wall full thickness
    - Damper: UL 555 listed (fire) or UL 555S (combination fire/smoke)
    - Fusible link: 165F (standard), 212F (kitchen hoods)
    - Access: Required on one side for inspection/reset
    - Retaining angle: Steel angle at each side of wall to hold damper
    - Duct connection: Within 24" each side, 1.5x duct area min

    COMBINATION FIRE/SMOKE DAMPERS:
    - Required at penetrations of smoke barriers (IBC 717.5)
    - Motor-operated blade (not just fusible link)
    - Connected to fire alarm system for automatic closure
    - Can be reset remotely or at damper
```

---

## CODE REFERENCE SUMMARY

### Key Code Sections

| Topic | IBC Section | IRC Section |
|-------|-------------|-------------|
| Stairs | IBC 1011 | IRC R311.7 |
| Guards | IBC 1015 | IRC R312 |
| Handrails | IBC 1014 | IRC R311.7.8 |
| Fire-rated construction | IBC 703-707 | IRC R302 |
| Firestopping | IBC 714 | IRC R302.4 |
| Fire dampers | IBC 717 | N/A |
| Plumbing (shower) | IPC 417 | IRC P2709 |
| Accessibility | IBC 1104-1110 | N/A (use ADA/ANSI A117.1) |

### Key Standards Referenced

| Standard | Title | Application |
|----------|-------|-------------|
| ANSI A117.1 | Accessible and Usable Buildings | ADA compliance details |
| TCNA Handbook | Tile Installation | Shower pans, tile methods |
| ASTM E119 | Fire Tests of Building Construction | Fire-rated assemblies |
| ASTM E814 / UL 1479 | Through-Penetration Firestop | Penetration firestopping |
| UL 555 / 555S | Fire Dampers / Smoke Dampers | HVAC penetrations |
| AWI Standards | Architectural Woodwork | Cabinetry quality grades |
| ASTM C840 | Application of Gypsum Board | Drywall installation |
| ASTM C1396 | Gypsum Board Products | Board specifications |

---

## REVIT API DRAWING NOTES

When drawing these details in Revit via API:

### Line Weights and Styles
- **Object lines (cut):** Pen weight 4-5 (medium-heavy)
- **Object lines (projection):** Pen weight 2-3 (light-medium)
- **Hidden lines:** Dashed, pen weight 1
- **Centerlines:** Center-dash, pen weight 1
- **Break lines:** Zigzag line style
- **Section cut (poche):** Filled region with solid fill pattern

### Detail Component Families
- Use Repeating Detail Components for:
  - Brick coursing
  - Concrete masonry units
  - Stud framing
  - Tile patterns
  - Insulation (batt or rigid)
- Use Filled Regions for:
  - Concrete (stipple pattern)
  - Earth/gravel (dot pattern)
  - Wood (grain pattern)
  - Gypsum board (no pattern, outline only)
  - Insulation (diagonal cross-hatch)
  - Metal (no pattern, outline with section marks)

### Annotation Standards
- Dimensions: Continuous dimension strings, aligned
- Keynotes: Element keynotes referencing CSI MasterFormat
- Material tags: At all materials in section cuts
- Detail references: Circle with detail number/sheet number
- Scale: 1-1/2" = 1'-0" (most interior details), 3" = 1'-0" (complex connections)

---

*Reference compiled from IBC 2024, IRC 2024, ADA/ANSI A117.1-2017, AWI Standards 3rd Edition, TCNA Handbook, UL Fire Resistance Directory, and manufacturer technical documentation (Schluter, USG, Armstrong, ClarkDietrich, 3M).*
