Knee Wall - SPF With Existing Insulation

Verify that installation area is free of:

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

energized 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 (including blockers under kneewalls in alignment with the interior side of the kneewall)

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

Install durable backing material over any escape holes in the air barrier

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

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

Apply SPF to prescribed R-value in a continuous layer over entire surface of knee wall from roof deck to attic floor air barrier 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

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

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