Do you need baffles with spray foam insulation?

Author: Prof. Zack Wilkinson III  |  Last update: Tuesday, December 23, 2025

Baffles should be used prior to an installation of spray foam to maintain the shingle warranty and most importantly to prevent any moisture build up from under the roof deck that could cause mold or rot. Every rafter bay should be vented for proper airflow for the entire attic space.

Why is spray foam a red flag for lenders?

Spray foam insulation is one of those many factors that can throw up a red flag to a mortgage lender. For a lender, your insulation matters because it affects crucial metrics such as the home's saleable value and energy efficiency rating.

Are insulation baffles necessary?

Baffles are often overlooked, but they play a crucial role in making sure your insulation works as effectively as possible.

What is the downfall of spray foam insulation?

While spray foam insulation can make a home more energy efficient, its downsides often out-weight its benefits. If spray foam insulation isn't installed correctly or is used in the wrong setting, it can cause all sorts of problems, from reducing ventilation to rotting wooden roof beams.

Does spray foam insulation need an air gap?

If spray foam is instead applied to the attic ceiling, ventilation may not be needed. An exception is with wood, tile, slate, or some asphalt shingle roofs that require an air gap for their warranties. In these cases, a 1-inch gap between the insulation and roof materials provides essential airflow and ventilation.

Spray Foam Bummers: Make Informed Decisions on Insulating Your Home

Do you need ventilation with spray foam insulation?

It depends. Spray foam insulation can reduce the need for traditional roof ventilation, but it doesn't completely replace it in every situation. Whether you need ventilation depends on your attic's setup (conditioned or unconditioned), local climate, and how moisture is managed.

What is the downside to foam insulation?

The discussion around the dangers of spray foam insulation often includes the potential for respiratory problems, particularly during the installation process and while the foam is curing. Furthermore, some spray foams can off-gas volatile organic compounds (VOCs), leading to indoor air quality issues.

Where should you not use spray foam?

Directly against electrical wiring or fixtures: Spray foam insulation should not be applied directly against electrical wiring, fixtures, or recessed lighting unless they are rated for contact with insulation. Contact with insulation can cause overheating and pose a fire hazard.

Why is it hard to sell a house with spray foam insulation?

Some Buyers May Be Uncertain Of Spray Foam Insulation.

If they don't know the contractor who installed it, they may worry that the foam was installed by people who didn't know what they were doing. Other buyers have heard negative stories about spray foam insulation.

How much does it cost to spray foam for 1500 square feet?

The cost to insulate an attic is usually between $1.50 and $3.50 per square foot. This price can change depending on the attic's size and how easy it is to get to. For a typical 1,500-square-foot attic, you pay $2,250 to $5,250.

How do I know if I need baffles?

Homes with both traditional and vaulted ceilings need attic baffles if they utilize vented roofs, which feature: Closed (or box) eaves, where the rafters are enclosed and vented via soffits. Ridge vents at the apex of the roof, and/or. Gable vents on the flat area between the roofline and the exterior walls.

Can you install baffles after insulation?

Note that if you used drywall or plywood to cover your roof rafters, you must remove it to install the baffles. If you have existing insulation, take it off the attic edges, precisely where you are installing the baffles. Each space between the rafters needs a baffle, and you must fit each one snuggly into the bay.

Should I remove my baffles?

Baffles are included in the design of an exhaust system to help make the exhaust a little bit quieter and more easily compliant with noise regulations. Removing said baffles will dramatically increase the sound of your bike's exhaust and give it a deeper, fuller sound.

Why do insurance companies not like spray foam insulation?

The chemical aspect of spray foam makes it very hard for standard insurance companies to provide coverage. Most standard lines insurance carriers want to write the risks with no liability not spray foam contractors that manufacture plastic every day in the field.

What not to tell a lender?

5 Things You Should Never Say When Getting a Mortgage
  • 'I need to get an extra insurance quote due to … ...
  • 'I can't believe how much work the house needs before we move in' ...
  • 'Please don't tell my spouse what's on my credit report' ...
  • 'I'm still working out the details on my down payment'

Does spray foam insulation void insurance?

Although spray foam insulation has been used in many homes for years, it has been known to cause issues of late with some insurance companies outright refusing to provide building insurance and mortgage lenders not accepting properties with spray foam insulation.

Why not to get spray foam insulation?

Spray foam insulation is known to cause a few health issues, including: Asthma. Sensitisation. Lung damage.

Does spray foam have a higher R-value than fiberglass?

Essentially, the higher a material's R-value is, the more effective it will be as an insulator. Closed-cell spray foam has an R-value of roughly 6.5 per inch while open-cell spray foam has an R-value of 3.5 per inch. The R-value of fiberglass is significantly lower at around 2.2 per inch.

What are the negatives of spray foam?

The Downsides of Using Spray Foam Insulation in Homes
  • It Can Lead to Mold. Spray foam insulation mold problems are quite common. ...
  • It Can Have a Foul Odor. Spray foam insulation is mixed on the job site, and improper ratios of chemicals are common. ...
  • It Can Lead to Termite Damage. ...
  • It's Too Airtight.

Can mold grow behind spray foam insulation?

Spray foam insulation is not a waterproofing product. If spray foam is installed in a basement or an attic that leaks, mold could grow. Another example of improper installation is the use of the wrong type of spray foam.

Should windows be spray foamed?

If you are having your windows professionally replaced, you will want to find a contractor that uses expanding spray foam around the window. This will best secure the window and protect it from any air or water infiltration.

What is the best alternative to spray foam insulation?

Instead of spray foam, Curtis recommends cotton denim insulation, which is typically made from industrial scraps.

Does spray foam insulation decrease home value?

Spray foam insulation provides an excellent air seal, reducing the workload on the HVAC system by minimizing air leaks. This not only extends the lifespan of the HVAC system but also improves comfort and energy efficiency, qualities that can boost a home's marketability and resale value.

How long does spray foam insulation last?

Spray foam insulation has an estimated life expectancy that varies from 80 up to 100 years. And that can be achieved with little to no maintenance at all. The material is strong and it can last for as long as your building can. Different from cellulose and fiberglass, spray foam does not deteriorate, sag, or settle.

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