4.1003.8 Installing Fiberglass Blown Insulation for Flat, Bowed, or Vaulted Ceilings (via Roof Side Lift)

Topic: 
Attics
Subtopic: 
Attic Ceilings
For supporting material, see Building America Solution Center.
Desired Outcome: 
Consistent, uniform thermal boundary Thermal boundary The separation between the interior and exterior environments of a building that slows heat flow and air barrier Air barrier The separation between the interior and exterior environments of a building that slows air flow to the point that no smoke movement is visible at 50 pascals of pressure difference across the boundary between the conditioned space and unconditioned space
TitleSpecification(s)Objective(s)
4.1003.8a
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 IC Insulation contact rated light fixtures will be replaced with airtight IC IC Insulation contact -rated fixtures

All recessed lights will be labeled as having an air leakage rate no more than 2.0 CFM CFM Cubic feet per minute when tested in accordance with ASTM ASTM ASTM International, www.astm.org 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 insulation 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 during the insulation installation process

4.1003.8b
Attic access

Fasteners will be removed from the J channel and the roof edge on the most easily accessible side of the house

Roof will be separated from the heel plate and siding roof will be lifted and propped to accommodate fill tube

Length of opening will be enough to allow ease of access and reattachment while minimizing potential damage from high winds

If subsheathing is present, access will be gained through subsheathing

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

Create access to the full attic cavity

Protect roof from wind damage during installation

Ensure ease of roof reattachment

Determine insulation installation technique

4.1003.8c
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

4.1003.8d
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 cavity will be filled to a consistent density

Fill tube will be inserted within 6" of the end of each attic cavity

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

Avoid overfilling of roof edges and above attic trusses

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 ASTM ASTM International, www.astm.org E84

Fill entire attic cavity to the prescribed R-value to reduce air infiltration Infiltration The uncontrolled passage of outside air into a building through unintended leaks in the building envelope

Avoid clogging of the cavity and the fill tube

Prevent damage to the ceiling

Allow roof to be returned to original position

Fire safety will be maintained

4.1003.8e
Roof reattachment

If existing J channel is damaged, it will be replaced

Existing sealant will be removed from the roof edge and J channel

At a minimum, new sealant will be reinstalled at the original location

Roof and J channel will be fastened to the original location with new screws

All seams, edges, and penetrations will be sealed as necessary

Prepare roof edge and J channel for reattachment

Reattach roof edge and J channel without leaks

4.1003.8f
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

4.1003.8g
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 completed

Comply with 16 CFR 460.17