SPF Roof Insulation - Unvented Roof Deck

Detail ID 4.0102.1
Topic
Attics
Subtopic
Interior Roof Insulation
Desired Outcome

Continuous, contiguous, and safe thermal boundary that prevents air movement @ 50 Pascals

SF Single Family Site-Built Housing
MH Manufactured Housing
MF Multifamily Housing

Specifications

  • SF
  • MH
  • MF
Specification Objective

Verify that installation area is free of:

active water leaks, fuel leaks (i.e., gas, oil, propane), and pest intrusions

energized or undammed knob and tube wiring

uncovered electrical junctions

improperly terminated devices (ventilation fans, dryers, plumbing stacks, condensate lines, combustion appliance flues/chimneys, etc.)

unshielded high-temperature devices (non-IC rated recessed lights, chimneys, flues, vents, etc.) unless they are zero clearance devices

insulation escape openings

Verify that installation area:

is intact, able to support insulation weight, and air sealed

Ensure roof deck can be safely insulated

  • SF
  • MH
  • MF
Specification Objective

Cover all existing attic ventilation openings (gable vents, ridge vents, roof vents, vented soffits, etc.) with a class II vapor retarder that provides a suitable substrate for SPF application and is mechanically fastened in place

Prepare the surface according to manufacturers specifications

Install flags at all utility junctions for future identification and ensure utility junctions remain accessible per local code requirements

Prevent insulation escape and condensation

Provide future access to utility junctions

  • SF
  • MH
  • MF
Specification Objective

Select insulation materials that have a flame spread and smoke development index of 75/450 or less when tested in accordance with ASTM E84 or UL 723

Select fire safe insulation

  • SF
  • MH
  • MF
Specification Objective

Remove contaminants from all SPF application surfaces that will prevent full adhesion or cause degradation

Verify all SPF application surfaces are in accordance with manufacturer specifications for moisture content and temperature

Properly bonded SPF

  • SF
  • MH
  • MF
Specification Objective

Apply SPF to prescribed R-value in a continuous layer from exterior wall top-plate to peak of roof and over all surfaces exposed to ambient temperatures using a pass thickness maximum in accordance with manufacturer specifications

In colder climates (IECC Zones 5-8), install SPF to a thickness of at least a class II vapor retarder or have at least a class II vapor retarder coating or covering in direct contact with the underside of the SPF

Continuous and contiguous pressure and thermal boundary that prevents vapor intrusion

  • SF
  • MH
  • MF
Specification Objective

Separate all foam products from living space with a thermal barrier material (e.g., 1/2" gypsum wallboard) as specified by applicable building code

If attic is used only for the service of utilities, foam will be separated from the attic space using a suitable ignition barrier covering or coating according to manufacturer's specifications

If attic is used for storage or occupancy, spray foam will be separated from the attic space using a thermal barrier material (e.g., 1/2" gypsum wallboard) as specified by applicable building code and manufacturer specifications

If code requirements are unclear, consult local code officials for clarification

Minimize ignition and combustion potential

  • SF
  • MH
  • MF
Specification Objective

Post a dated receipt signed by the installer that minimally includes: Installed insulation type, coverage area, installed thickness, and installed R-value

Comply with 16 CFR 460.17 and document contract compliance