Code of practice for patent glazing

IS 10439 - Scope: Key Formulas, Tables & Specifications

1. Scope Overview

• IS 10439 covers design and specifications for aluminium alloy glazing bars and glazing units.
• It includes section modulus requirements, material properties, and glazing unit types.

2. Section Modulus for Aluminium Glazing Bars (Clause 5.1)

Use this table to select section modulus Z based on span and working force.

3. Double Glazing Units (Clause 6.1)

• Double glazing reduces thermal conductivity by ~50% compared to single glass.
• Optimum air space: up to 20 mm for maximum insulation.
• Reduces sound transmission.
• Consult manufacturers for patent glazing with composite seals.

4. Fastenings (Clause 3.2.5)

• Nuts, bolts, screws: Aluminium, steel, or brass.
• Must conform to relevant IS standards.

5. Units & Symbols (SI Units)

Summary Diagram: Section Modulus Selection

graph LR
A[Total Working Force (kN)] --> B[Span (m)]
B --> C[Required Section Modulus Z (cm³)]
C --> D[Select Aluminium Glazing Bar]

**Use IS

IS 10439: Terminology and Definitions - Key Points

1. Terminology (Clause 2.0)

• Defines key components of patent glazing such as:
  • Muntin Section
  • Draught Excluder
  • Fixing Bolt Shoe Stop (Bottom)
  • Extruded Aluminium Alloy Glazing Bar
  • Storm Clip
  • Continuous Aluminium Cover Strip or Capping
  • Lead Wing or Aluminium/Plastic Flashing
  • 6 mm Rough-cast Wired Glass
  • Asbestos or PVC Cushion

2. Units and Symbols (SI Units)

• Force: (1,N = 1,kg \cdot m/s^2)
• Energy: (1,J = 1,N \cdot m)
• Power: (1,W = 1,J/s)
• Pressure: (1,Pa = 1,N/m^2)

3. Double Glazing Units (Clause 6.1)

• Thermal conductivity of double glazing ≈ half that of single glass.
• Optimal air gap for insulation: up to 20 mm; beyond that no significant improvement.
• Double glazing reduces sound transmission.
• Consult manufacturers for composite seal types.

4. Section Modulus for Aluminium Glazing Bars (Clause 5.1)

• Section modulus (Z) varies with total working force (kN) and span length (m).
• Example values for spans 1.0 m to 3.4 m and forces 1.0 kN to 4.0 kN are tabulated (see Table 1 in Clause 5.1).

Summary Diagram: Patent Glazing Components

graph TD
  A[Extruded Aluminium Alloy Glazing Bar] --> B[Muntin Section]
  A --> C[Fix

IS 10439 – Materials for Patent Glazing: Key Points

While IS 10439 does not provide explicit formulas, it specifies materials and typical sections for patent glazing:

Materials:

• Glazing: 6 mm rough-cast wired glass (commonly used for safety and durability).
• Glazing Bars: Extruded aluminium alloy sections (H and 2 muntin types).
• Cushion: Asbestos or PVC cushions to hold glass in grooves and provide sealing.
• Cover Strips: Continuous aluminium cover strips or cappings.
• Flashing: Lead wing (fur), aluminium, or plastic flashing to direct water away.
• Fixings: Storm clips fixed to glazing bars and fixing bolt shoes with stops at the bottom.

Typical Sections (Fig. 1 Reference):

• Muntin Sections: 2 muntin and H muntin aluminium alloy bars.
• Draught Excluder: To prevent air leakage.
• Stop: At the bottom to secure glass.

General Specifications:

• Use extruded aluminium alloy for strength and corrosion resistance.
• 6 mm wired glass for safety and impact resistance.
• Cushion materials (asbestos/PVC) must ensure tight sealing and prevent glass damage.

Summary Table:

flowchart LR
    Glass["6 mm Wired Glass"]
    Cushion["Asbestos/PVC Cushion"]
    GlazingBar["Extruded Aluminium Alloy Glazing Bar"]
    CoverStrip["Continuous Aluminium Cover Strip"]
    Flashing["Lead/Aluminium/Plastic Flashing"]
    Fixing["Storm Clip & Fixing Bolt Shoe"]

    Glass --> Cushion
    Cushion --> GlazingBar
    GlazingBar --> CoverStrip
    CoverStrip --> Flashing
    GlazingBar --> Fixing

This layout ensures weather-tight, durable, and safe patent glazing as per IS 10439.

IS 10439: Information Requirements for Design - Key Points & Tables

1. Necessary Information for Design (Clause 4.3)

• Glazing area & dimensions
• Position of openings (roof or walls)
• Construction and fixing details
• Span & spacing of roof principals or stanchions
• Roof pitch
• Height from ground
• Type of glass
• Ventilation details and operation
• Type & weight of flashing

2. Section Modulus of Aluminium Alloy Glazing Bars (Clause 5.1, Table 1)

Use this table to select glazing bar section modulus based on force and span.

3. Fastenings (Clause 3.2.5)

• Nuts, bolts, screws: Aluminium, steel, or brass per relevant IS standards.

4. Double Glazing Units (Clause 6.1)

• Thermal conductivity ≈ half of single glass.
• Optimal air space: up to 20 mm for insulation.
• Consult manufacturers for composite

IS 10439: Design Considerations Summary

1. Section Modulus of Aluminium Alloy Glazing Bars (Clause 5.1, Table 1)

• Section modulus (Z) depends on total working force (kN) and span length (m).
• Example values for spans from 1.0 m to 3.4 m and forces from 1.0 kN to 4.0 kN:

Units of Z: cm³ (assumed typical for section modulus)

2. Double Glazing Units (Clause 6.1)

• Double glazing reduces thermal conductivity (~50% of single glass).
• Optimal air gap: up to 20 mm for best insulation.
• Improves sound insulation.
• Design adjustments needed when using factory-made double glazing units.

3. Fastenings (Clause 3.2.5)

• Nuts, bolts, screws: Aluminium, steel, or brass.
• Must conform to relevant Indian Standards.

4. Design & Fixing Details (Clause 4.4)

• Early agreement on flashings and fixing methods.
• Contractor responsible for preparatory work (drilling, pockets, rebates).
• Detailed shop drawings recommended.
• On-site dimension verification essential.

Key Formula for Section Modulus (Z):

[ Z = \frac{M}{\sigma} ]

Where:

• (M) = Maximum bending moment (kNm)
• (\sigma) = Allowable stress (MPa)

Use values from Table 1 for selecting appropriate glazing

Key Specifications & Formulas for Installation and Fixing (IS 10439)

1. Fastenings (Clause 3.2.5)

• Nuts, bolts, screws: Aluminium, steel, or brass.
• Must conform to relevant Indian Standards for materials and dimensions.

2. Design & Fixing Details (Clause 4.4)

• Early agreement on flashings and fixing details.
• Provide detailed shop drawings and drilling requirements to steel contractors.
• Dimensions must be verified on site.
• Structural/general contractor preferred for preparatory work (drilling, pockets, rebates).

3. Section Modulus for Aluminium Alloy Glazing Bars (Clause 5.1, Table 1)

Use this table to select glazing bars with adequate section modulus based on span and load.

Summary Diagram of Installation Process

flowchart TD
   

IS 10439: Weatherproofing & Drainage Key Points

Weather Resistance (Clause 5.9)

• Water Channels: Provide grooves in glazing bars to drain water outside.
• Seating: Continuous edge support with oiled asbestos cord, PVC cushions, etc.
• Pitch: Minimum recommended roof pitch is 20°.
• Bottom Overhang: Glass should overhang at least 20 mm beyond bottom support.
• Lap: Overlap upper glazing tier over lower by at least 50 mm.
• Draught Excluder: Use between glass and lower support to prevent rain/snow ingress.
• Flashings: Extend at least 75 mm over glass; avoid capillary water entry.
• Rainwater: No concentration of rainwater flow over patent glazing.
• Pollution: Seal wings/cappings if dust or grit may clog water channels.

Flashings & Fixing (Clause 4.4)

• Early design agreement on flashings/fixings.
• Provide detailed drawings and dimensions.
• Coordinate steel work drilling and glazing installation.

Section Modulus for Aluminium Glazing Bars (Clause 5.1, Table 1)

Walkways (Clause 5.19)

• Walkways for cleaning: support glazing bars with
  • Max second moment of area, I = 120 × 10⁴ mm⁴
  • Section modulus, Z = 27 × 10³ mm³

flowchart TD
    A[Water Channels] --> B[Drain water outside]
    C[Seating] --> D[Continuous edge support]
    E[Pitch ≥

IS 10439: Safety and Protection Measures - Key Points

1. Safety Glass & Fastenings (Clause 3.2.5)

• Nuts, bolts, screws: Aluminium, steel, or brass per relevant IS standards.
• Use safety glass conforming to IS specifications (second revision).
• Wired and figured glass must meet IS specifications.

2. Double Glazing Units (Clause 6.1, Table A-6)

• Two panes fused or joined with composite seal.
• Thermal conductivity ≈ half of single glass.
• Optimal air gap: up to 20 mm for best insulation; beyond no added benefit.
• Reduces sound transmission.
• Consult manufacturers for patent glazing use.

3. Section Modulus for Aluminium Glazing Bars (Clause 5.1, Table 1)

4. Units and Definitions (SI Units)

• Force: Newton (N) = kg·m/s²
• Pressure/Stress: Pascal (Pa) = N/m²
• Energy: Joule (J) = N·m
• Power: Watt (W) = J/s

Summary Diagram: Safety Measures Flow

flowchart TD
    A[Select Glass Type] --> B{Single or Double Glazing?}
    B -->|Single| C[Use standard glass]
    B -->|Double| D[Check air gap ≤ 20 mm]
    D --> E[Consult manufacturer for patent glazing]
    A --> F[Select Fastenings]
    F --> G[Nuts, bolts, screws: Aluminium/Steel/Brass]
    G --> H[Conform to IS standards

IS 10439: Maintenance and Inspection - Key Points

1. Fastenings (Clause 3.2.5)

• Nuts, bolts, screws must be aluminium, steel, or brass.
• Must conform to relevant Indian Standards for material and quality.

2. Inspection Guidelines (Clause 8.1)

• Periodic inspections to:
  • Prevent moisture ingress.
  • Replace faulty/damaged glazing materials.
  • Replace cracked or broken glass.

3. Design Considerations: Section Modulus for Aluminium Alloy Glazing Bars (Clause 5.1, Table 1)

(Section modulus values increase with span length and force)

4. Double Glazing Units (Clause 6.1)

• Two panes fused or joined with composite seal.
• Thermal conductivity ~50% of single glass.
• Air space up to 20 mm improves insulation; beyond this, no significant gain.
• Reduces sound transmission.
• Manufacturer consultation recommended for patent glazing.

Summary for Maintenance and Inspection:

• Use standard fastenings (aluminium/steel/brass).
• Schedule regular inspections to maintain glazing integrity.
• Replace damaged components promptly.
• Refer to section modulus tables for design and replacement sizing.
• Consider double glazing for improved insulation and soundproofing.

flowchart TD
    A[Periodic Inspection] --> B{Check for}
    B --> C[Moisture Entry]
    B --> D[Faulty Glazing]
    B --> E[Cracked/Broken

IS 10439 - Properties of Various Types of Glass (Appendix A, Clause 5.6.1)

This clause provides general guidance on selecting glass types based on key properties:

Key Properties to Consider:

• Light Transmission: Percentage of visible light passing through.
• Weather Resistance: Durability against environmental exposure.
• Fire Resistance: Ability to withstand fire without failure.
• Strength: Mechanical strength, including impact resistance.
• Thermal Transmittance (U-value): Rate of heat transfer through glass.

Relevant IS Codes:

• IS 2835-1977: Specifications for transparent sheet glass.
• IS 2440-1975: Minimum illumination levels for glazing.

Typical Glass Types & Properties (Indicative):

Formula for Thermal Transmittance (U-value):

[ U = \frac{1}{R} = \frac{k}{d} ]

• (k) = Thermal conductivity of glass (W/m·K)
• (d) = Thickness of glass (m)
• (R) = Thermal resistance (m²·K/W)

flowchart LR
    A[Select Glass Type] --> B{Consider Properties}
    B --> C[Light Transmission]
    B --> D[Weather Resistance]
    B --> E[Fire Resistance]
    B --> F[Strength]
    B --> G[Thermal Transmittance]
    C --> H[Refer IS 2835]
    G --> I[Calculate U-value]

Summary: Use Appendix A for property ranges; consult IS 2835 for specifications; ensure illumination per IS 2440; and evaluate glass based on the above criteria for patent