Spray Foam Insulation Roof Problems

Applying an even sheet of foam to the underside of a roof or other space can eliminate the routes that water vapor uses to leave the house.

Spray foam insulation roof problems.

Spray foam insulation problems there are several majors spray foam installation problems that have been associated with the use and application of spray foam in a home some of these problems will vary based on how much of the spray foam is used where it is placed who applies the spray foam and the conditions in this environment. Poor application includes off ratio spraying of the material bad odors and the lack of adhesion. Lstiburek takes blame for bad language. Almost all of the problems associated with spray foam roof insulation comes down to incorrect application.

Cost is certainly a factor spray foam is more expensive than fiber insulation but there s another side to the issue. Insulating with spray foam insulation at the roof line will cause moisture problems with the roof sheathing. Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing. In other words the spray has not been used in the right way or the mixture is not right for the location.

It has been said that insulating with spray foam insulation at the roof line will lead to moisture problems with the roof sheathing. Thus the air in the attic is connected with the air in the house. Incorrectly installed spray foam insulation can trap moisture in the home encouraging rot and mold problems. The poor application of spray foam insulation by an untrained or unlicensed contractor can lead to several problems according to fine home building.

In an unvented attic scenario to limit air leakage as well as any associated condensation at the roof line a continuous air barrier is required. If you leave the insulation in the attic floor after insulating the roofline the attic will be cooler in winter than if you remove the insulation. To get the best performance out of spray foam insulation you must cover the roof rafters and surrounding areas as thoroughly as possible. Even small gaps can allow the passage of warm air through the foam rendering the foam all but useless as an insulator.

Moisture is also another huge issue when it comes to spray foam insulation in an attic. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. Whereas too little spray foam insulation can leave for thermal bypass because of the complete lack of insulation in the attic. An internet search reveals nightmare anecdotes about lingering odors having to excavate badly installed foam and health issues attributed to improperly applied foam.