Is Spray Foam Insulation Bad For Your Roof?

If you're considering insulating your attic with spray foam, you might be worried about your roof. You may have even read some horror stories online about how roofs have failed after installing spray foam insulation. Is spray foam insulation really bad for your roof?

South Central Services has insulated hundreds of homes near Chambersburg, Pennsylvania. Attic insulation is one of our most popular services.

When installed correctly, spray foam isn't bad for your roof. When certain variables or factors are not considered, spray foam insulation could contribute to roof problems.

By the end of this article, you will understand:

• What factors must be considered when installing spray foam against the roof
• What risks are present if the spray foam is installed incorrectly

Don't have time to read right now? Check out everything you need to know at a glance.

When Installed Correctly, Spray Foam Is Not Bad For Your Roof.

Spray foam insulation is not inherently bad for roofs. As long as the product is installed correctly, spray foam insulation will not cause any harm. Some of the factors that qualified contractors keep in mind are:

• The correct foam thickness
• The correct foam application
• The correct type of foam
• The climate zone implications

If spray foam insulation is installed at the wrong depth, or if the wrong type of foam is used, the installation could cause issues for the roof.

This is why working with a qualified spray foam contractor is vital. Qualified professionals understand the implications of your climate zone and are well-versed in building science. The right contractor will know how the installation of spray foam will impact the rest of the home, including the roof deck.

If installed incorrectly, spray foam could be a contributing factor to a roof rotting or failing. If installed correctly, those risks should be mitigated.

What Are The Risks To Using Spray Foam On A Roof?

If the spray foam is installed incorrectly, what are some of the risks for the roof? When spray foam is installed incorrectly, it could contribute to the following:

• Shingle failure
• Deck failure
• Deck warping
• Condensation issues

Let’s examine each of these in more detail.

Spray Foam Insulation Should Not Cause Shingle Failure.

If spray foam was installed incorrectly, it could contribute to shingle failure. An improper application of spray foam could trap moisture in the wood substrate it was sprayed against. If the wood roof deck holds onto moisture, shingles could fail.

When installed correctly, spray foam insulation will not trap moisture in the substrate.

Spray Foam Insulation Should Not Cause Deck Failure.

The same conditions that could cause shingle failure can also lead to deck failure. If the wood roof deck holds onto moisture for an extended period of time, it could begin to rot.

Spray Foam Insulation Should Not Warp Your Deck.

Another consequence of the roof deck holding onto moisture could be warping. The trapped moisture, combined with varying temperatures outside, could warp the decking.

Spray Foam Insulation Should Not Create Condensation Issues.

When a qualified professional installs spray foam, there should be no risk of condensation issues. A qualified professional knows how vapor barriers and your climate zone interact together to create a healthy roof.

If the foam is installed by someone who is not qualified, there is the risk of condensation build-up in the attic and the roof deck.

Spray Foam Installed By A Qualified Contractor Is Safe For Your Roof.

The idea of finding a qualified spray foam contractor may seem daunting. The stakes are high for the health of your roof.

The reality is that no matter where spray foam is being installed in your home, you must work with a professional contractor. Spray foam insulation is a unique product that is manufactured on-site through a chemical reaction. Even without the concerns of trapping moisture in your roof deck, you would need to find a qualified installer.

Our team created this checklist to help homeowners evaluate their local contractor options. Working with a contractor you trust can mitigate the risks of improperly installed spray foam in your roof.

The Bottom Line About The Risks Related To Roof Spray Foam

Spray foam insulation can be an effective insulation option for your attic that has no ill effects on the health of your roof. As long as you work with a qualified contractor who knows the implications of your climate zone and the type and thickness of the foam, your roof should not experience any condensation issues or failures.

Now that you understand why spray foam isn’t bad for roofs when installed correctly, your next step is to:

• Decide if you want to insulate your attic floor or the underside of your roof
• Compare spray foam insulation to blown-in cellulose
• Estimate the cost of insulating your attic with spray foam