Spray Foam Insulation for Builders
Tighter envelopes. Better scores. Happier buyers.
Air sealing and insulation in one trade visit, full documentation for raters and inspectors, and a limited lifetime warranty on the foam. ComfortSeal is an insulation line item that helps sell the house.
R-values are installed values at the stated thickness from IAPMO ER-974 and ER-975, Table 1. The higher the R-value, the greater the insulating power. Ask your seller for the fact sheet on R-values.
A differentiator you can put in the brochure
Wins with buyers
"Insulated with ComfortSeal, backed by a limited lifetime warranty" is a line your sales team can use with every buyer — comfort, not construction jargon.
Performance for the spec book
IAPMO-evaluated products (ER-974, ER-975), Class I fire data, and attic and crawl space provisions for the closed cell — documentation your raters and inspectors will ask for, ready to go.
One spec, every plan
A two-product lineup means the same spec repeats cleanly across every plan in your community, so crews, raters and inspectors know what to expect.
Where it fits in the homes you build
New construction
- ✓ A continuous air seal that can support blower-door and HERS targets
- ✓ Open cell interior + closed cell exterior in one visit
- ✓ Data sheets and evaluation reports for the rater and inspector
Production communities
- ✓ Certified crews trained on both products
- ✓ Air sealing and insulation in one trade visit
- ✓ A buyer-facing warranty story for the whole community
Custom & luxury homes
- ✓ Even temperatures room to room, floor to floor
- ✓ NRC 0.75 sound dampening for quiet interiors
- ✓ An air seal around penetrations and rim joists
Coastal & storm zones
- ✓ Class II vapor retarder — 0.45 perms @ 2 inches of closed cell
- ✓ Fungi resistance on the closed cell — no growth (ASTM G21)
- ✓ Wind uplift rated 210 psf (UL 1897)
Choose the foam by assembly, not by house
Most homes use both products. What decides which goes where is what each assembly needs from its insulation.
Exterior walls
- ✓ ComfortSeal HFO where you want a Class II vapor retarder (0.45 perms at 2 inches) and a rigid, bonded layer
- ✓ ER-975 lists R-25 at 3.5 inches and R-39 at 5.5 inches, so a partial fill can still hit a high target
- ✓ ComfortSeal 500 where the wall is designed to dry to the interior; confirm vapor control for your climate zone
Attic rooflines
- ✓ Foam at the roof deck brings ducts and equipment inside the envelope (unvented attic guide)
- ✓ ComfortSeal HFO when rafters are shallow and you need the most R-value in that depth
- ✓ In attics, ComfortSeal 500 takes a prescriptive ignition barrier or a listed coating (DC315 or No-Burn Plus ThB, ER-974 Table 5); ComfortSeal HFO needs no coating in attics entered only to service utilities, up to 10 in. on the roof deck and 6 in. on walls (ER-975)
Interior walls & floors
- ✓ ComfortSeal 500 for bedrooms, baths, media rooms and floors between levels
- ✓ NRC 0.75 and STC 39 for quieter interiors
- ✓ Expands about 100 times its liquid volume to fill around wiring and plumbing
Crawl spaces & rim joists
- ✓ ComfortSeal HFO: 1.44% water absorption (ASTM D2842) and no fungal growth (ASTM G21)
- ✓ ComfortSeal HFO needs no ignition barrier coating in crawl spaces entered only to service utilities, up to 10 in. overhead and 6 in. on walls (ER-975)
- ✓ Seals the rim joist, a common air-leakage point in framed houses
Building on the coast or in a storm zone? In hot, humid climates moisture pushes from outside in, so closed cell on the walls facing the weather and open cell inside the sealed envelope is a common pairing. Our humid and coastal climates guide walks through it.
Where the reports apply. ER-974 and ER-975 recognize both products as nonstructural insulation in Type V construction under the IBC and one- and two-family dwellings under the IRC. Passes are limited to 6 in. for ComfortSeal 500 and 3 in. for ComfortSeal HFO, and ComfortSeal HFO is not for contact with soil or standing water. Confirm barrier requirements with the building department.
Where spray foam fits in the build
One trade visit handles air sealing and insulation, but only if it lands at the right point in the schedule. Here's the typical order. Confirm inspection steps with your local building department.
1 · Dry in the shell
Roof on, windows and exterior doors in, sheathing complete. Substrates must be dry (both data sheets call for moisture below 18%) and within the data sheet temperature limits.
2 · Finish every rough-in
Plumbing, electrical, HVAC, low-voltage and blocking go in first. Foam seals around boxes and penetrations as it goes. Adding a wire run after spraying means cutting into a finished air seal.
3 · Pass rough inspections
Framing and rough mechanical inspections usually come before insulation, because the foam covers what the inspector needs to see.
4 · Clear the site on spray day
Keep other trades out of the work area during spraying and until the installer says it's safe to return.
5 · Trim, inspect, document
Open cell is trimmed flush so drywall lies flat. Record installed thickness and the R-value the evaluation report lists at that thickness, and keep the data sheets and report in the job file.
6 · Barriers, then drywall
Living spaces need a thermal barrier, usually the drywall itself. Attics and crawl spaces follow ignition barrier rules. Our barrier guide explains the difference.
Everything your inspector or rater asks for
No chasing manufacturers for test data. Every ComfortSeal document lives in the tech library — download what you need, hand it to your code official, and keep the job moving.
In the tech library
Open cell and closed cell
ComfortSeal 500
- ✓ Interior walls, attics, and sound control
- ✓ Expands 100× — a complete air seal
- ✓ NRC 0.75 · STC 39 · ER-974
ComfortSeal HFO
- ✓ Exterior walls, humid climates, storm zones
- ✓ Class II vapor retarder + 210 psf wind uplift rating
- ✓ 0.45 perms at 2 in. · ER-975
What builders ask before they spec
Which product should I spec for my wall assemblies?+
ComfortSeal 500 open cell (R-13 in a 2x4 wall) is the workhorse for interior walls, attics, and sound control. ComfortSeal HFO closed cell (R-25 in the same wall) adds a Class II vapor retarder, a rigid bonded layer, and a 210 psf (UL 1897) wind uplift rating — the choice for exterior applications, humid climates, and storm zones.
Does spray foam help with HERS scores and energy code compliance?+
It can support them. Spray foam insulates and air seals in one step, and a continuous air seal can support blower-door results and HERS ratings. Actual results depend on the house, the climate and the rest of the envelope.
What documentation is available for inspectors and raters?+
Both products carry full technical data sheets and evaluation reports — ER-974 for ComfortSeal 500 and ER-975 for ComfortSeal HFO — plus Class I fire test data (ASTM E84) and the attic and crawl space provisions in each report. Everything is available in the tech library.
How does the buyer warranty work?+
When a certified ComfortSeal contractor installs the insulation, the foam is backed by a limited lifetime warranty on the foam, for the life of the home. Installation workmanship is the installing contractor's responsibility.
When does spray foam go in during construction?+
After the shell is dried in, every rough-in is complete and rough inspections have passed, and before the insulation inspection and drywall. Confirm the inspection sequence with your local building department.
What R-value goes on the insulation certificate?+
Use the value the evaluation report lists for the installed thickness, not R-value per inch multiplied by inches, which overstates the result. ER-975 lists ComfortSeal HFO at R-25 at 3.5 inches, R-28 at 4 inches and R-39 at 5.5 inches. For ComfortSeal 500, see the R-value by thickness guide or the R-value calculator.
Can other trades work while the foam is sprayed?+
No. Keep the work area clear during application and until the installer confirms it's safe to return.
Build homes buyers can feel the difference in
Talk to our team about pricing and certified installers in your market, or connect your insulation contractor with our certification program.