4.1003.15 Installing Fiberglass Blown Insulation for Flat, Bowed, or Vaulted Ceilings (via Gable End Access)

Topic: 
Attics
Subtopic: 
Attic Ceilings
Desired Outcome: 

Consistent, uniform thermal boundary and air barrier between the conditioned space and unconditioned space

TitleSpecification(s)Objective(s)
4.1003.15a
Attic, ceiling, and roof verification

All combustion appliance flues will be terminated to the outdoors and terminations will maintain proper clearance above snow loads

A distance no less than 2" will be maintained between any combustion appliance flue and combustible materials, unless zero clearance flue is in place

All ventilation systems will maintain a continuous connection and terminate to the outdoors

All broken mushroom vents will be replaced or removed and sealed

All plumbing stacks will be terminated to the outdoors

Non- IC rated light fixtures will be replaced with airtight IC -rated fixtures

All recessed lights will be labeled as having an air leakage rate not more than 2.0 CFM when tested in accordance with ASTM E 283 at a 75 pascals pressure differential

All obvious ceiling penetrations will be sealed

The space between combustion appliance flues and the ceiling will be sealed with fire-rated materials

All roof, attic, and ceiling assemblies will be structurally sound:

  • Loose ceiling panels will be secured
  • Temporary ceiling bracing will be recommended during the insulation installation process

Dishing and pooling issues that allow standing water will be addressed

All known roof water leaks will be repaired before installing installation

Ensure occupant and worker safety

Verify attic space is ready to insulate

Ensure structural integrity of the roof and ceiling assembly

Prevent intrusion of bulk moisture

Prevent damage while installing insulation

4.1003.15b
Attic access

Access to the attic cavity will be created through the gable vents.

Attic will be visually inspected for the location of existing insulation, wiring, flues, obstructions, hazards, and construction type

Create access to the full attic cavity

Maintain the integrity of the roof truss

Determine technique for installing insulation

4.1003.15c
Blowing machine set up

Blowing machine pressure test will be performed with air on full, feed off, and gate closed

Hose outlet pressure will be set in accordance with manufacturer specifications

Ensure machine is capable of delivering uniform insulation density and coverage

4.1003.15d
Fiberglass blown insulation installation

Insulation will be installed to a density of 1.5 to 1.6 pounds per cubic foot

Using fill tube, 100% of each roof cavity will be filled to a consistent density

Insulation will be installed into the void of the attic cavity:

  • If existing insulation is roof-mounted, insulation will be blown below
  • If existing insulation is ceiling-mounted, insulation will be blown above
  • If existing insulation is mounted at both locations, insulation will be blown in between

Flame spread and smoke-developed index for insulation will be a flame spread rating of 25 or less and a smoke development rating of 450 or less when tested in accordance with ASTM E84​​​​​​​

Fill entire attic cavity to the prescribed R-value to reduce air infiltration

Avoid clogging of the cavity and the fill tube

Prevent damage to the ceiling

Fire safety will be maintained

4.1003.15e
Replace Gable End Vent Covers

Reinstall the gable end vents

Prevent pest intrusion into attic

Protect installed insulation

4.1003.15f
Verification of details

Installation process will be considered complete when installer has verified that damage has not occurred to the roof or ceiling assemblies during the installation process

Verify the integrity of the house has been maintained

4.1003.15g
Onsite documentation

A dated receipt signed by the installer will be provided that includes:

  • Insulation type
  • Coverage area
  • R-value
  • Installed thickness and minimum settled thickness
  • Number of bags installed in accordance with manufacturer specifications

Document job completion to contract specifications

Confirm amount of insulation installed

Ensure ability to match bags required for total area complete

Comply with 16 CFR 460.17