6 Ways Extreme Heat Damages Your House (And How to Prevent Them)

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Extreme heat is defined in various ways depending on who you ask. Some sources describe it as multiple successive weeks of temperatures that are more than 10 degrees Fahrenheit above average for a region. Others say extreme heat occurs when air temperatures are over 90 degrees with high humidity. Either way, there's no doubt that high temperatures are uncomfortable and potentially damaging to a home. With the increasing number of heat waves hitting the U.S. as climate change advances, extreme heat is a major concern for homeowners.


Despite the long list of potential problems that extreme heat can cause, hope remains. There are numerous ways to limit or avoid much of the damage that it can do to your home. Here are several ways that extreme heat can damage your home and what you can do to protect against it.

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Extreme heat often goes hand in hand with high humidity. This pairing can have devastating effects on your home and wallet. Many home insurance policies don’t cover indirect damages that high temperatures can cause, which can leave you on the hook for substantial repair bills.

1. Roof Leaks

Cold wintertime temperatures don't do your roofing material any favors. On a similar note, extreme heat can quickly destroy the integrity of your home's roof. While your roof is busy protecting you and your belongings on a typical day, it also has to do battle with radiant heat from the attic below and the air above as it tries to hold up against damaging UV rays from the sun year-round. Toss in an extreme heat wave or two during the summertime and the resulting deterioration can cause roof leaks, with related problems escalating quickly.

How to Prevent Roof Damage in Extreme Heat

To minimize radiant heat damage to your roof, you can take one or more of several steps.

  1. Install a fan: ​Installing a dual-power vent fan in your attic will reduce the heat and humidity that build up above your home’s living spaces 24 hours a day. Lowering the attic temperature is better for your roofing materials and less humidity means a lower chance of dangerous mold and mildew growth.
  2. Protect the roof from UV rays: ​UV rays are notorious for shortening the life span of any roof regardless of the air temperature. Adding a protective coating to your roof won’t eliminate UV-ray damage, but it can slow down the molecular process of degradation and help prevent leaks. When it’s time to replace your roof, consider installing light-colored materials to reflect the sun’s rays instead of absorbing the heat.
  3. Plant trees: ​For long-term protection, plant trees in your yard. Your roof will appreciate the shade they will provide when they have grown.

2. Paint and Siding Damage

Extreme heat and high humidity attack your home's paint and siding with a one-two punch. The heat expands wooden siding, while the moisture in the air soaks into the boards. When the temperature drops, the siding contracts again. The combination can cause irreversible damage to the siding material itself and causes paint to bubble and crack, leaving your walls exposed and vulnerable to moisture damage behind the siding.


How to Prevent Paint and Siding Damage in Extreme Heat

The best way to prevent further damage on your paint and siding is to maintain the paint diligently. Add caulk or filler in cracks and touch up missing paint spots often. If your budget allows, consider replacing vulnerable wooden siding with a material that’s less prone to heat damage, such as heat-resistant vinyl or fiber cement siding. Stucco is particularly well suited to dry climates — it's a heat-resistant siding material with some insulating qualities and is mostly maintenance-free.

3. Buckling Flooring

Extreme heat can even negatively affect your wood floors inside the house. High humidity can cause the boards to expand and potentially buckle. The damage is often irreversible and leads to expensive repairs or replacement.



How to Prevent Flooring Damage in Extreme Heat

The simplest way to keep humidity from becoming a factor in your home is to leave the windows closed at night to keep out cool, moist air. Running your A/C in auto mode at night will allow it to keep humidity levels low without having to run constantly.

4. Air Conditioning Unit Overuse

Home insurance doesn't cover normal wear and tear on your HVAC systems. During extreme heat events, your air conditioner must work extra hard to keep your home comfortable. The higher demand on your A/C can prematurely age the system, which increases its chances of failing when you need it most.


How to Prevent Overworking Your A/C Unit in Extreme Heat

There are numerous methods to save energy in your home and reduce the workload on your A/C system, even during high-heat periods. Here are six ways to avoid overworking your air conditioner in extreme heat.

  1. Keep drapes and blinds closed during the daytime to prevent radiant heat from the sun.
  2. Turn up the thermostat a few degrees if possible.
  3. Add insulation to your attic and walls.
  4. Hire a professional inspector to perform an energy audit in your home and follow the recommendations.
  5. Seal air and moisture leaks around doors and windows with high-quality exterior caulk.
  6. When it’s time to repaint your home, consider light colors that reflect heat away from your home.

5. Mold Growth

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Mold and mildew love to grow in warm, damp places around your house during extreme heat events. Your basement, crawl space, and attic, which are fine during normal weather, can trap moisture and heat and become breeding grounds for mold during stretches of unusually high temperatures.


How to Prevent Mold Growth in Extreme Heat

Consider installing a vapor barrier throughout your crawlspace to keep moisture from entering your house. For basements, maintain low humidity levels with a dehumidifier. You can also employ alternative dehumidification methods, including running fans or using more natural, passive devices.

One way to keep your basement or crawl space humidity levels in check is to install a passive dehumidifier. Here's how to install your own.

  1. Drill several holes in a gallon-size or 5-gallon bucket.
  2. Fill the bucket with rock salt, charcoal, or silica gel beads. The filler will absorb water from the air.
  3. Pour out the water that pools at the bottom of the bucket regularly.

6. Settling Foundation

Image Credit: Tanut Nitkumhan/iStock/GettyImages

Perhaps the most devastating and costly damage that extreme heat can cause is the settling and subsequent cracking of your home's foundation. It's an extreme situation, but it can happen when groundwater evaporates from excessive heat. The sudden change in the soil moisture can allow house foundations to shift and crack. Not only is the situation bad for the overall structure when it rains, but the water won't shy away from pouring into the new cracks and causing even more damage.

How to Prevent Foundation Damage in Extreme Heat

Running your sprinklers may seem like a great way to add soil moisture and prevent foundation damage, but it will only replace a fraction of the groundwater around your home. Your best defense against foundation damage in extreme heat is being in a state of constant inspection and making repairs as soon as you suspect damage to prevent the problem from getting worse.



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