They are expected to insulate our homes and buildings based on the assumption of dead air and only the principles of advection and convection r factor.
Spray foam retrofit attic.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry.
Before any retrofit work is done inspect the work area for active knob and tube wiring bathroom fans venting into attics roof leaks and other hazardous conditions.
Spray foam insulation for the attic can be somewhat expensive.
This seals and insulates the attic which helps keep the temperatures more moderate usually only about a 10 15 degree temperature difference from the inside of the home.
Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor.
Repair these conditions prior to adding insulation.
Why retrofit an existing home with spray polyurethane foam.
Foam lok retrofit foam is specifically designed for injection and pour applications into existing wall cavities and block wall constructions.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
Spray foam retrofit attic these past several years advantage home performance has received numerous requests from home owners who want to eliminate attic vents and upgrade their attic insulation to half pound spray foam insulation installed on the underside of the roof deck these homeowners are ahead of the curve.
Choosing spray foam for this need instead could cost you well over 6 per square foot in some markets if your r value code requires.
Nothing unusual about that.
The vast majority of existing homes in the world are insulated with a air use insulator fiberglass cellulose.
Foam lok retrofit foam provides the same physical properties characteristics of the foam lok open cell spray applied insulation system and allows the applicator to insulate and air seal existing walls.