Spray foam
Spray foam, where it earns its cost
Closed cell foam for rim joists, crawl space and basement walls, roof decks, pole barns, metal buildings and new construction. For most attics, blown in is still the better value, and we will tell you so.
Or text a photo to 740-590-5352.
Open cell and closed cell
Two different materials out of the same kind of gun, according to the DOE's Building America guide [1]:
| Open cell | Closed cell | |
|---|---|---|
| R-value per inch | About R-3.6 | About R-6 |
| Water vapor | Lets vapor through | A vapor retarder at 2 inches |
| Liquid water | Absorbs it, up to one third of its volume | Will not absorb water |
| Strength | Adds little | Substantially increases racking strength |
| Cost | Lower installed cost | Higher installed cost |
Where we use it
- Rim joists and sill plates
- Crawl space and basement block walls
- The underside of roof decks, cabins and sun rooms
- Pole barns, shops and metal buildings
- New construction, including flash and batt and under slabs
Flash and batt
A thin coat of closed cell foam first to seal the air leaks, then fiberglass or rock wool batts fill the rest of the cavity. Most of the air sealing of foam for less money. The DOE lists it as one of the hybrid ways to use spray foam [1].
More detail, with sources, on our insulation questions page.
Questions about this job
Is spray foam better than blown in?
Not for every job. For a typical vented attic floor, blown in fiberglass or cellulose is usually the better value. Foam earns its cost where air sealing and moisture matter most: rim joists, block walls, roof decks, metal buildings.
Open cell or closed cell?
For most jobs around here we recommend closed cell. It insulates, seals air and stops vapor in one layer, and it does not soak up water. On sloped roof rafters the DOE rates closed cell Preferred in all climates and open cell only Acceptable in cold climates, with vapor retarders [1].
What about roof leaks?
Roofs leak no matter what is under them. Closed cell bonds to the deck and keeps a leak where it came in. Keep the roof in good shape and pick the insulation for the other 364 days of the year.
Get a price
Tell us about the job
A few details and a photo or two is all it takes. We call you back to set up a time to come out, measure, and give you one written price for the whole job.
Sources
- U.S. Department of Energy, Building America. Which Spray Foam Is Right For You? Appropriate applications for open-cell and closed-cell foam insulation (2009).