Which is better, spray foam or radiant barrier?

Author: Deshaun Bradtke  |  Last update: Tuesday, February 10, 2026

Spray foam insulation doesn't protect attic spaces from radiant heat, but does protect them from convection and conduction. In the summer, radiant heat is the biggest contributor to heated attic spaces, so spray foam insulation may not be as effective in keeping attics cool.

Is radiant barrier better than spray foam?

If you already have insulation in your attic or space, it is easy to install radiant barrier alongside existing insulation. As a bonus, the performance of your insulation will dramatically improve. Spray foam insulation does not offer this same level of flexibility.

What is the downside of radiant barriers?

Simply put, the biggest possible problem with any kind of radiant barrier is dust. To understand why dust creates issues for all kinds of radiant barriers, it's important to understand how they work: Radiation transfers heat directly outward from an energy source.

What is the disadvantage of spray foam insulation?

Environmental damage (spray foam insulation isn't recyclable, and it can release greenhouse gases that are over 1,000 times more harmful than carbon dioxide) Ventilation issues (spray foam insulation covers all gaps, which can lead to dampness, condensation and wood rot)

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.

What is the Best Attic Insulation? (Spray Foam vs. Fiberglass vs. Cellulose) | Foam University

What is the downfall of spray foam insulation?

Spray foam insulation can cause bad smells

There's a pretty unfortunate problem associated with spray foam insulation – bad smells, or more specifically, a fishy odour that seems to hang around for months after installation. Whilst unpleasant, the issue is rare, especially if installed correctly by professionals.

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.

When 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.

Can mold grow behind spray foam insulation?

Mold and mildew can begin growing behind the insulation which can go unnoticed until it's already become a huge problem. This often happens when the spray foam isn't installed correctly and space is left between the insulation and the wall, which allows moisture in and gives mold the perfect place to grow, unfettered.

What is better than spray foam insulation?

While both types of insulation are great choices for home insulation, fiberglass insulation is generally considered to be safer than spray foam insulation. This is because spray foam contains a special type of chemical called isocyanate, which is toxic when inhaled.

What is the average cost to install a radiant barrier?

Installing a radiant barrier costs $1,700 on average, but often ranges between $710 and $2,840 depending on whether your pro uses a foil or spray on type.

Does radiant barrier affect WIFI?

With Wi-Fi signals, unless the radiant barrier is between you and the router, there is unlikely to be any impact.

Does a radiant barrier need an air gap?

This is because an air gap provides an additional layer of insulation that helps to prevent heat from passing through the barrier and into the living space. If you are installing a radiant barrier, it's recommended to leave an air gap of at least 25mm (1 inch) between the barrier and the surface it's installed on.

Are radiant barriers worth it?

Some studies show that radiant barriers can reduce cooling costs 5% to 10% when used in a warm, sunny climate. The reduced heat gain may even allow for a smaller air conditioning system. In cool climates, however, it's usually more cost-effective to install more thermal insulation than to add a radiant barrier.

Is spray foam worth the money?

Spray foam insulation does cost more than traditional options, but over time it pays you back in energy savings, and you can't really put a price on the comfort of your family.

What is the best brand of spray foam insulation?

FIND THE BEST SPRAY FOAM INSULATION BRAND FOR YOUR JOB
  • Natural Polymers. Dedicated to low-VOC signatures and environmentally friendly raw materials, Natural Polymers develops easy-to-use spray foam products that exceed in innovation. ...
  • SWD Urethane. ...
  • Carlisle Spray Foam Insulation. ...
  • Elastochem.

What are the negatives of spray foam?

Addressing the question of "what are the disadvantages of spray foam insulation" requires a balance between acknowledging its drawbacks and providing solutions to mitigate them.
  • Health Concerns. ...
  • Cost Factors. ...
  • Installation Complexities. ...
  • Potential for Mold Growth. ...
  • Respiratory Difficulties and Off-gassing. ...
  • Long-term Effects.

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.

What is the best insulation to prevent mold?

Fiberglass insulation is constructed of tiny shards of glass that form pockets to trap air and help restrict the transfer of heat. Its naturally mold resistant in that the material itself is not a food source for mold.

Where not to use expanding foam for walls?

While it is hugely useful, it should not be used to solve all problems. One such example is electrical boxes. Expanding foam shouldn't be used in these locations as it could cause jams that would be expensive to repair. So avoid using it around sockets or light fixtures, or any electrical components in the property.

What is the lifespan of spray foam?

Spray foam insulation lasts for 80 years to 100 years, but closed-cell spray foam will last a little longer than open-cell spray foam. For many homeowners, this lifespan will extend beyond the entire time they own their house. Closed-cell spray foam lasts longer than open-cell spray foam due to its rigid structure.

What is the best insulation for walls?

Foam Board or Rigid Foam

Foam boards -- rigid panels of insulation -- can be used to insulate almost any part of your home, from the roof down to the foundation. They are very effective in exterior wall sheathing, interior sheathing for basement walls, and special applications such as attic hatches.

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'

Why can't you sell a house with spray foam insulation?

Independent chartered building surveyor, Geoff Hunt said due to government initiatives open cell spray foam has gained popularity in recent years. But he called for 'caution and refusals on higher-risk applications' as mortgage lenders struggle to assess spray foam.

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