Spray Foam Insulation Roof Problems

Poor application of the spray foam insulation.

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. Below we are going to list the most common problems with using spray foam insulation in your home s attic or in any area inside of your home. An internet search reveals nightmare anecdotes about lingering odors having to excavate badly installed foam and health issues attributed to improperly applied foam. Over time trapped moisture can cause serious problems.

Cost is certainly a factor spray foam is more expensive than fiber insulation but there s another side to the issue. Spray foam insulation is a better insulator than mineral wool loft insulation as you need less of it to get the same insulating effect. Placement errors during installation attics are the main spots in a home that are filled with unusual shapes gaps and spaces where air bubbles have the potential to form when you spray foam insulation. But that only works if the installer can get it into the places where most of the air leakage happens.

However there are still some issues with spray foam insulation on the roof that can be avoided. In fact spray foam insulation can help avoid problems like these. So what are the problems with spray foam insulation. 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. 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. Some spray foam insulation sets rigid and can also be used to help reinforce roofs that are suffering from nail fatigue when the nails used to hold slates in place rust or support cavity walls where the wall ties are failing causing cracks and bulges in walls. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.

Lstiburek takes blame for bad language. Poor application includes off ratio spraying of the material bad odors and the lack of adhesion. It really should be called spray foam insulation and air barrier. Insulating with spray foam insulation at the roof line will cause moisture problems with the roof sheathing.

Incorrectly installed spray foam insulation can trap moisture in the home encouraging rot and mold problems. Spray foam insulation is an incomplete name.