How to Keep Wildfire Smoke Out of Your House

Don’t Get Smoke in Your Eyes

California has experienced a tremendous increase in wildfires and with that a rise in smoke pollution. Even if you are not in immediate proximity to a wildfire, weather systems can convey wildfire smoke into your neighborhood. High levels of smoke particulates from nearby and even not so nearby wildfires can infiltrate your house and irritate the nose and lungs, sometimes causing serious health problems for family members with breathing issues.

It may be fine for smoke to get into your eyes while listening to the classic Jerome Kern and Otto Harbach show tune, but not in your home. In this post we cover key pointers on how to keep wildfire smoke out of your house in three critical areas:

Attic and crawl spaces
Windows and doors
Chimneys

Seal Leaky Attic Spaces

Attic and crawl spaces are ventilated to enable the circulation of fresh, outside air to help prevent mold growth, mildew and other preventable problems that result from stagnant air in dark spaces. Attic ventilation is accomplished using eave vents or bird hole ventilation located around the outside of your attic space. The crawl space has similar venting screens, usually located around the base of the home.

Attic and crawl space ventilation is a building code requirement, and for good reason. You want air to circulate in these spaces. What is not good is when ventilated air leaks out of the attic or crawl space and into the living areas of your home. This is particularly not good when the outside air is filled with smoke.

Here is how to keep wildfire smoke out of your house by preventing attic or crawl space ventilated air from getting into your house and into your lungs:

Seal the Attic (or Crawl Space)

As you probably guessed, sealing the attic means exactly that – closing off all possible leaks from your attic to your home. This can include, but is not limited to, can lights, ceiling fans, electrical connections, ventilation pipes (such as bathroom exhaust fans and kitchen hoods), registers and fire sprinkler heads.

How can you tell if these possible penetrations are already sealed? Take a look around any fixture or piping that leads into your living space. If there’s dirt around any of them, you’ve got a leak. The dirt collects there as a result of air pressure, which is particularly high when your HVAC system is running, forcing particles and debris into the gap.

For small gaps, silicone or acrylic caulk can fill in the leaky spaces. To plug openings bigger than a quarter-inch, use low-expansion polyurethane foam.

2. Seal the Attic (or Crawl Space) Entrances

Doors to your attic or crawl space are a perfect breach point for outdoor air, and outdoor air that brings smoke with it. Don’t assume that if the door is closed, the air in the space is sealed off. This is only true if the door has proper weather strip sealing.

Sometimes weather stripping is forgotten when installing an attic or crawl space entrance. Even when it is properly installed, weather stripping degrades over time. If you have an old house it is particularly important to see if the weather stripping is still acting as an effective barrier. Even if your house isn’t that old, check the condition of the weather stripping just to make sure.

3. Seal Ductwork

Leaky ductwork is a prime source for outside air to make its way into your home. When your HVAC system turns on, it creates a positive pressure in the duct system required to deliver conditioned air throughout the house. If your attic air contains smoke or other contaminants, the pressure in a leaky duct system serves to pull contaminated air into the duct system and distribute it into your living spaces.

This can be resolved with proper duct sealing if the integrity of your ductwork is still good. If your ductwork is old or faulty you might require new, properly sized and secured duct work. Sealing or replacing leaky ductwork is best performed by a qualified HVAC expert and can help keep wildfire smoke out of your house.

4. Check for Proper Insulation

An attic that isn’t properly insulated can allow drafts into your house, and those drafts could contain smoke particles. Even if you are in a smoke-free area, improperly insulated or uninsulated attics are a major source of energy loss. If your attic is properly insulated, your HVAC system runs more efficiently, and a more efficient HVAC system means lower energy bills. For more on attic insulation, see our post on the Top Benefits of Attic Insulation.

5. Be Safe

If you’re going up in the attic to perform any kind of inspection work, follow these basic safety tips:

Attics get hot. During the warm months, you’ll only want to go up there on a cool day, or, at the very least, early in the morning or late in the afternoon.
Wear protective gloves and a mask; there are things up there you don’t want to breathe or get on your hands!!
Essential tools include a flashlight or droplight and a couple of pieces of wood to span two or three joists so you can look in hard to reach areas.

Windows and Doors

Windows and doors can be a direct access point for outside air. Again, don’t assume that just because windows and doors are closed, they aren’t leaking outside air.

Inspect your windows to ensure proper weather stripping is in good condition. Also ensure all windows are secure, latch correctly, and do not have any offset. If you have older windows, it may be time to upgrade to a more energy-efficient and secure model. Not only will you save money with lower energy bills, you’ll be more comfortable inside and have greater confidence that you can keep smoke out of your home.

Check your doors for intact weather stripping around the door trim and the base of the door. Remember that a garage door is, well, a door, even if bigger than most. That means it is a doorway for outside air and smoke. If you have an attached garage, you want to make sure both the garage door and the entrance to your house are properly sealed. Not only does this keep smoky air out of the house, it keeps bugs out as well.

If you have an old garage door or you are concerned about whether it is properly sealed, it’s probably best to call a garage door expert to perform an inspection.

Fireplace Chimneys

Fireplace chimneys are one of the biggest sources of air leaks in your home. Make sure to close the chimney damper completely shut when not in use. And make sure you open the damper before starting a fire, as that’s sure to get smoke in your room.

Schedule a thorough cleaning and inspection of the chimney annually. In addition to cleaning the soot that accumulates inside the chimney, a professional chimney sweep checks for any cracks or leaks and ensures the flashing is in good condition.

But since the whole point of this blog is how to keep wildfire smoke out of your house, use of a fireplace is counterproductive. Sure, there’s something about a fire that literally makes you feel warm. However, fireplaces are notoriously energy inefficient as well as a source of air pollution. If you don’t want to seal up the fireplace altogether, consider using a gas insert. The experience is very similar to a “real” fireplace, with the added advantage of improved energy efficiency and environmental friendliness, less fuss and muss, plus you’ll have a smoke-free living space.

Circulating Air

Your HVAC system continually circulates conditioned (warmed or cooled) air throughout your home. The HVAC system also has an air filter designed to trap smoke and other particulates. This air filter should be changed at least annually, and in many cases twice a year, before each warming and cooling season. A clogged air filter not only contributes to inefficient HVAC operation but it can no longer filter air as designed.

We’ve previously cleared the air about air filtration in our post, Air Filtration and Indoor Air Quality.

Upgrading your air filtration system can significantly reduce smoke and other contaminants even further. Here are 6 Ways An Air Purifier Benefits Better Breathing. For additional peace of mind, consider buying an AQI (Air Quality Index) Monitor to get an accurate reading of the smoke and other pollutants in your home. This helps you assess what remediation efforts you might want to take.