For attics and crawl spaces being used for storage the above applies.
Exposed spray foam insulation in basement.
Currently leaning towards closed cell spray foam to r20 same in the joist bays.
Spray foam is applied by a high pressure applicator gun directly to the area being insulated.
When the coating foam combination passes the screening test the combination is approved for use in the attics and crawl spaces but the coating is not recognized in the building codes as an ignition barrier.
Instead it is.
I am in the beginning stages of planning out my to be finished basement which is currently unfinished with builder blanket insulation on the wall.
Open cell foam has an r value of roughly 3 9 per inch.
Also its primary role is to fill crannies and nooks as well as your basement.
In addition foam in place insulation is blown into walls or other cavities where it then hardens.
Despite the name spray foam insulation isn t exclusively sprayed.
Indeed the foam can fit crevices gaps and wall cavities.
For indoor applications per building code requirements foam left exposed is required to be covered by a 15 minute thermal barrier in habitable spaces of a structure.
For unoccupied space or that of which is being used for equipment servicing the above does not apply.
However most building codes allow the installation of unprotected rigid foam in a crawlspace that has no open connection to a basement as long as the foam has passed alternative testing procedures.
Instead it can be injected poured or sprayed.
Most ceilings are made of 1 2 drywall.
Many spray foam manufacturers test their spray foam systems with an intumescent coating in place of the ignition barrier.
If you ve got spray foam insulation in an attic for example it s probably already separated from the living space by a thermal barrier.
In some cases explanation.
The foam rapidly cures and adheres in place.
Dow styrofoam and owens corning foamular are two products that pass the burn test and can be left unprotected in an isolated crawlspace.
My worry is that in some areas of my basement i get condensation during the summer months against the builder s poly.
Existing concrete block wall cellulose or spray foam insulation why basement insulation is the most 0 5 pcf open cell spray foam basement ceiling with exposed joists.
Since the spray foam is energy efficient you can correctly use it as an air sealing solution.
But the spray foam is still exposed to the attic and needs an ignition barrier.