# Glazing Systems

## System Types

### Decision Matrix
| System | Max Height | Thermal | Cost | Use |
|--------|------------|---------|------|-----|
| Storefront | 10'-12' | Good | $$ | Retail, entries |
| Curtain wall | Unlimited | Good-Excellent | $$$$ | High-rise, signature |
| Window wall | 10'-14' | Good | $$$ | Low-rise commercial |
| Punched openings | Per window | Excellent | $-$$$$ | Residential, traditional |
| Structural glass | 15'-20' | Fair | $$$$$ | Atrium, showcase |

---

## Storefront Systems

### Standard Dimensions
| Component | Dimension |
|-----------|-----------|
| Frame depth | 1-3/4" to 2-1/2" |
| Face width | 2" typical |
| Max panel size | 50 SF typical |
| Max glass weight | 25 lbs/SF |

### Configuration Options
| Feature | Options |
|---------|---------|
| Finish | Anodized, painted (AAMA 2604/2605) |
| Thermal break | Standard or high-performance |
| Door types | Single, pair, auto slide |
| Hardware | Push/pull, panic, closers |

### Performance Ratings
| Rating | Typical Value |
|--------|---------------|
| U-factor | 0.45-0.65 |
| SHGC | 0.25-0.40 |
| Air infiltration | 0.06 CFM/SF |
| Water resistance | 6.24 PSF |
| Structural (DP) | 35-50 PSF |

---

## Curtain Wall Systems

### System Types
| Type | Description | Use |
|------|-------------|-----|
| Stick-built | Assembled on-site piece by piece | Low-rise, complex geometry |
| Unitized | Pre-assembled panels, installed | High-rise, repetitive |
| Point-supported | Glass held at discrete points | Signature, minimal frame |

### Mullion Types
| Type | Description |
|------|-------------|
| Captured | Glass held by applied cap |
| Structural glazing (SSG) | Glass bonded to frame |
| Toggle/dry glazed | Mechanical retention |

### Typical Dimensions
| Component | Dimension |
|-----------|-----------|
| Mullion depth | 4" to 8" |
| Mullion width | 2" to 2-1/2" visible |
| Module width | 5' typical |
| Module height | Floor-to-floor |

### Performance
| Rating | High-Performance Target |
|--------|-------------------------|
| U-factor | 0.25-0.35 |
| SHGC | 0.20-0.35 |
| Air infiltration | 0.06 CFM/SF |
| Water resistance | 15 PSF |
| Structural (DP) | 60-100 PSF |

---

## Glass Types

### Glass Makeup
| Type | Description | Use |
|------|-------------|-----|
| Monolithic | Single pane | Interior, mirrors |
| Insulated (IGU) | 2+ panes with air space | Standard exterior |
| Laminated | 2 panes with interlayer | Safety, security |
| Tempered | Heat-treated for strength | Safety, wind loads |
| Heat-strengthened | Partially tempered | Thermal stress |

### IGU Construction
```
Typical makeup:
[Outdoor] Glass / Air Space / Glass [Indoor]
         1/4"     1/2"      1/4"     = 1" overall

High-performance:
[Outdoor] Glass / Argon / Glass [Indoor]
         1/4"    1/2"    1/4"    + Low-E coating
```

### Coatings
| Type | Location | Purpose |
|------|----------|---------|
| Low-E (hard coat) | #2 or #3 | Solar control |
| Low-E (soft coat) | #2 | Energy efficiency |
| Reflective | #1 or #2 | Glare, solar control |
| Tinted | In glass | Solar control, aesthetics |

### Surface Numbering
```
#1 = Exterior surface of outer pane
#2 = Interior surface of outer pane
#3 = Exterior surface of inner pane
#4 = Interior surface of inner pane
```

---

## Glass Performance Values

### U-Factor (Lower = Better)
| Configuration | U-Factor |
|---------------|----------|
| Single pane | 1.04 |
| Double pane, clear | 0.47 |
| Double pane, Low-E | 0.30 |
| Double pane, Low-E, argon | 0.26 |
| Triple pane, Low-E, argon | 0.18 |

### SHGC (Lower = Less Solar Heat)
| Configuration | SHGC |
|---------------|------|
| Clear glass | 0.70-0.80 |
| Tinted | 0.40-0.60 |
| Low-E | 0.25-0.40 |
| High-performance Low-E | 0.20-0.30 |

### VT (Visible Transmittance)
| Desired Effect | VT Range |
|----------------|----------|
| Maximum daylight | 0.60-0.80 |
| Balanced | 0.40-0.60 |
| Glare control | 0.20-0.40 |

---

## Safety Glazing Requirements

### Locations Requiring Safety Glazing (IBC 2406)
- Doors and sidelites (within 24" of door)
- Shower and tub enclosures
- Railings and guards
- Within 36" of walking surface and 60" of bottom edge
- Sloped glazing (skylights)
- At pools and hot tubs (within 60")

### Safety Glass Types
| Type | Impact Resistance | Breakage Pattern |
|------|-------------------|------------------|
| Tempered | 4× stronger than annealed | Small cubes |
| Laminated | Holds when broken | Cracks but stays in place |
| Wired | Limited | Holds in frame |

---

## Hurricane/Impact Glazing

### Florida Requirements
| Zone | Requirement |
|------|-------------|
| HVHZ (Miami-Dade) | Large missile (9 lb 2×4 @ 50 fps) |
| Rest of Florida | Small missile or large missile (varies) |

### Impact-Resistant Options
| Type | Description |
|------|-------------|
| Laminated (0.090" PVB) | Standard impact |
| Laminated (0.060" PVB × 2) | Enhanced impact |
| Impact-resistant film + frame | Retrofit |
| Hurricane shutters | Exterior protection |

### Required Testing
- TAS 201: Large missile
- TAS 202: Uniform load
- TAS 203: Cyclic pressure
- Miami-Dade NOA (Notice of Acceptance)

---

## Skylight Systems

### Types
| Type | Structure | Use |
|------|-----------|-----|
| Curb-mounted | On raised curb | Flat roof |
| Self-flashing | Integrated flange | Sloped roof |
| Ridge | Along roof ridge | Natural vent |
| Barrel vault | Curved form | Atrium |
| Pyramid | 4-sided | Highlight |

### Glazing Options
| Material | Weight | Impact | UV | Cost |
|----------|--------|--------|-----|------|
| Glass (tempered) | Heavy | Good | Excellent | $$$ |
| Glass (laminated) | Heavy | Excellent | Excellent | $$$$ |
| Polycarbonate | Light | Excellent | Good | $$ |
| Acrylic | Light | Fair | Good | $ |

### Performance Concerns
- U-factor typically 0.50-0.80 (poor)
- SHGC concerns (heat gain)
- Condensation at frame
- Drainage/flashing critical

---

## Detailing Considerations

### Sill Conditions
| Type | Description |
|------|-------------|
| Flush sill | Level with floor (accessibility) |
| Raised sill | Above floor (weather protection) |
| Recessed sill | Below floor (drainage concerns) |

### Head Conditions
| Condition | Detail Needs |
|-----------|--------------|
| At structure | Steel angle or embed |
| Below soffit | Transition flashing |
| At parapet | Counter-flashing |

### Jamb Conditions
| Condition | Detail Needs |
|-----------|--------------|
| At masonry | Jamb anchor, sealant |
| At stud wall | Buck, waterproofing |
| At column | Custom profile |

### Movement Accommodation
| Building Height | Movement Allowance |
|-----------------|-------------------|
| 1-3 stories | 1/4" - 3/8" |
| 4-10 stories | 3/8" - 1/2" |
| 10+ stories | 1/2" - 3/4" or more |

---

## Thermal Bridge Mitigation

### Problem Areas
- Frame at slab edge
- Mullion at spandrel
- Sill at interior
- Around openings

### Solutions
| Solution | Location |
|----------|----------|
| Thermal break frame | In mullion profile |
| Insulated spandrel | Behind opaque panels |
| Thermal isolator | At slab edge |
| Warm edge spacer | IGU perimeter |

---

## Specification Considerations

### Performance Specs to Include
- Design pressure (DP rating)
- U-factor and SHGC
- Air infiltration rate
- Water penetration resistance
- Structural deflection limits (L/175 typical)
- Acoustic rating (if required)

### Submittal Requirements
- Shop drawings with setting blocks
- Glass samples and calculations
- Structural calculations
- Mock-up (large projects)
- Warranty documentation

### Installation Requirements
- Setting blocks at quarter points
- Edge clearance per manufacturer
- Sealant compatibility
- Drainage provisions
- Protection during construction
