Spray Foam or New-Build Smell That Won't Go Away: What Can You Do?

Quick answer: A mild new-home smell that fades over a few months is normal. A strong, sharp or fishy smell that lasts for weeks after spray foam usually isn't: call the installer, your builder and the foam manufacturer first. Dry fog is not a fix for chemical off-gassing.

Is a strong new-home or spray foam smell normal?

Only if it's mild and fading. Maybe you moved into a brand-new home in Leander, Kyle or Pflugerville, or just had spray foam added to your attic, and the smell is still going strong.

Two very different things can be going on. Some of these smells fade on their own with time and fresh air. Others mean something went wrong during installation, and only the builder or installer can fix that. Our dry fog treatment is not a fix for chemical off-gassing, so this guide starts with how to tell the two apart and who to call.

What counts as a normal new-home smell?

A normal new-home smell is mild and slowly fades. It comes from fresh materials: paint, cabinets, engineered wood and vinyl plank flooring, carpet, caulk, adhesives and new furniture. Many of them give off volatile organic compounds (VOCs), chemicals that drift into the air as materials dry and age, for months after they're installed.

A few things are typical:

• It's strongest in the first weeks and slowly fades over months.
• Heat makes it stronger. A closed-up house in a Texas summer, or an attic that tops 130 degrees, speeds up off-gassing, so the smell can seem worse on hot afternoons.
• Tight homes hold it in. Newer homes are sealed well to save energy, so they don't trade indoor air for outdoor air the way older, leakier homes do. Our guide to new homes and tight homes explains why.

When is a spray foam smell a sign of a problem?

When the smell is strong and lasts well past the re-entry time. Spray foam is mixed from two chemical parts right at your house. Installed correctly, most of the smell should clear within a few days, following the manufacturer's instructions for how long to stay out and ventilate. Call the installer if:

• A strong smell lasts well beyond the installer's stated re-entry time, or keeps going for weeks
• The smell is fishy, sharp or like ammonia, rather than a mild plastic smell
• The foam looks wrong: sticky, soft, crumbly, pulling away from framing, or unevenly colored
• The smell is stronger on hot days and seems to come from the attic or walls
• People in your family don't want to be in the house because of the smell

Foam that wasn't mixed or applied correctly may never stop smelling. That isn't something cleaning, fresh air or any air treatment can solve. It's a problem for the installer and the foam manufacturer.

Who should you call first?

Start with the people who can fix the source, in this order:

1. The spray foam installer. Tell them what you smell, where and when. Ask them to look at the foam and share the manufacturer's installation and re-entry guidance.
2. Your builder, if it's a new home. Report it in writing while the home is still in its first year, and keep copies.
3. The foam manufacturer. Most have a technical support line, and they can tell you what the installer should have done.
4. An independent indoor air professional, such as an industrial hygienist, if you want to know what's actually in your air. That's their field; we don't measure or analyze indoor air.
5. Your HVAC company, to set up ventilation that brings in fresh air on purpose (more on that below).

If anyone in your family has concerns about how the smell is affecting them, talk with your doctor.

What helps while you sort it out?

Fresh air, a cool house and dry air help most. These steps ease a normal new-home smell, and they're sensible while you wait on the installer or builder:

• Ventilate. Open windows on mild, low-pollen days. Run bath fans and the range hood, as long as they vent outdoors.
• Bring in fresh air on purpose. An ERV (energy recovery ventilator) or a fresh-air intake tied to your HVAC system swaps stale indoor air for outdoor air, and an ERV also limits how much of our summer humidity comes in with it. Our sister company, Gold Eagle Services, can recommend the right option for your home.
• Keep the house cool and dry. Don't let the house get hot while you're away, and keep indoor humidity at 50 percent or below.
• Change the HVAC filter soon after move-in. Construction dust loads new filters fast.
• Air out new furniture and mattresses in the garage or an open room before bringing them in, when you can.
• Skip air fresheners and candles. They add more to the air and make it harder to tell whether the smell is fading.

Finished a remodel instead of a new build? Our guide to clearing dust and fumes after a remodel covers that.

Where does Pure Maintenance fit?

Only after the source is fixed, and only for everyday odors.

What our treatment isn't: the whole-home dry fog treatment is not made to treat chemical off-gassing from spray foam, paint, flooring or furniture. It doesn't remove VOCs, and it won't fix foam that was installed wrong. If the foam is the source, the installer has to address it first.

Where it can fit: once the installer and builder have dealt with any problem, and a new home settles in, families sometimes want a fresh start for the whole house before the kids' rooms are set up. Our whole-home dry fog treatment, made with the patented Pure Maintenance VaPURE system, carries a fine hydrogen peroxide and peracetic acid fog through every room, closet and the new ductwork without getting things wet, and a surface protectant follows. On treated hard, non-porous surfaces it helps control the growth of odor-causing microorganisms, and it's done in one day.

If you call us about a spray foam smell, we'll ask about the installer first, and we'll tell you if we're not the right next call.

Common questions

How long does new-home smell last?

It's usually strongest for the first few weeks and fades over several months: faster with good ventilation, slower in a hot, closed-up house.

Will a dry fog treatment get rid of spray foam smell?

No. We don't claim it does. A lingering spray foam smell needs the installer and manufacturer. Our treatment is for everyday odors on hard surfaces once any installation problem is resolved.

Can a portable air filter help?

A portable air filter with an activated carbon stage can help with some odors in a single room while you work on the source. It won't fix foam that keeps giving off a smell.

Get a free phone consultation

Book a free phone consultation. A Comfort Advisor will call you, learn what's going on in your home and send a written quote based on square footage. Pure Maintenance Austin, brought to you by Gold Eagle Services, serves all of Central Texas, including College Station, Round Rock, Georgetown, San Marcos, Bastrop and Marble Falls.

Call 512-904-4646 or email IAQ@goldeagleservices.com. We're open Monday through Saturday, 7am to 7pm.