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Is Opening Crawl Space Vents Really Worth It? Find Out the Truth

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The never-ending debate about opening and closing crawl space vents has left many people in limbo. Some homeowners know the downside of opening vents, but they can’t withstand the sweltering summer heat. They believe opening vents is the best way to cool their homes in summer. What they forget is that a vented crawl space puts them at a higher risk of water damage. So, don’t take this issue lightly. Is there a way out? Read on to get the answers.

While local codes in Florida, encourage homeowners to leave the crawl space vents open, it doesn’t forbid them from sealing their fixtures. Whether you want to encapsulate the crawl space and condition it or leave it exposed to the elements, the choice is yours. But there are conditions that you have to meet.

We encourage you to seal vents and enclose with a plastic vapor barrier because the vents will continue letting in moist air, so you won’t be able to control moisture.

Crawl Space Vents Are Retrogressive

If there’s one thing that vents instigate the most, it’s condensation. This fixture is open 24/7. On hot days, when the air is moisture-laden, it can increase the relative humidity in the crawl space significantly. Every one-degree change results in a 2.2% increase in humidity level. If the temperature changes by 20 degrees, the humidity will soar by a whopping 44.4%.

It doesn’t help that the logic behind crawl space vents is faulty, though people don’t often see it. Your home will be much healthier and drier if you sealed them. This way, you will be able to control moisture.

Why You Should Avoid a Vented Crawl Space

Over the years, studies have shown that crawl spaces with vents harm the home in many ways. These openings let in warm moist air during summer. When this air gets into the crawl space, it increases moisture levels and encourages many problems. Moisture problems will continue growing until these fixtures are sealed.

The number one problem that arises is condensation. It happens when warm, moist air comes into contact with cold surfaces. As the warm moist air cools, it will get to a point where it will give up moisture.

That’s when you will have moisture droplets. Condensation increases dampness and encourages wood rot, wall staining, and rust. If the issue isn’t addressed, water puddles may form on the floor of your crawl space.

The warm air from the outside weakens wooden support structures in your crawl space, specifically joists and beams. With time, these structures won’t be able to support the load above, and this can lead to structural failure.

More than half of the air in your living space originates from the crawl space. If your crawl space measures 1,000 square feet, that’s roughly 10 gallons of moisture ending up in your home. This air will cause wall paint to peel, rust to form and start eating away at metal surfaces, and force your HVAC to work extra hard.

The outside air isn’t clean. It’s packed with many harmful particles like dust, pollutants, and mold spores. Upward-moving air will bring them right into your home. When you inhale this air, you’re likely to develop breathing problems. Anyone with asthma will suffer the most, as their condition could worsen.

When cooler air gets into the crawl space, it goes up into your home and creates a stack effect. You may have to run your HVAC for many hours just to create a comfortable home, and this could translate into higher energy costs.

Seal Crawl Space Vents

If you want a dry, clean, comfortable home, seal the crawl space vents with durable, airtight vent covers. Studies show homes with sealed and encapsulated crawl spaces use less energy, are mold-resistant, and have better air quality than those of their unsealed counterparts. You will enjoy significant dryness during hot and humid summer months when everyone is struggling to tame moisture.

Additional steps include insulating the crawl space walls with rigid panels like ExTremeBloc­™, encapsulating the space with a thick and durable 20-mil CrawlSeal™ vapor barrier, and dehumidifying the air with an energy-efficient dehumidifier.

Get in touch with the crawl space experts at Alpha Foundations for a free crawl space inspection and quote. We are happy to assess your crawl space and tell you the improvements you should make to keep it dry and clean.

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