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Not Sure of What to Make of Your Crawl Space Ventilation?

Learn how crawl space venting affects the quality of indoor life in your home and what you can do about it.

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For many years, homeowners in Grand Junction, CO, built their homes with crawl space vents and never thought it would drive up moisture levels. What happened? Moisture-laden air would flow into their crawl spaces, build up, and condense on cooler surfaces. Condensation would then encourage mold growth and other issues. 

If you’re struggling with the thought of venting your crawl space or wondering how it elevates moisture, this article will provide you with the answers you need. But most importantly, we will show you how to keep moisture under control. 

crawl space ventilation problems

What’s the Origin of Crawl Space Venting? 

Many people have grown up seeing vents in their crawl space. Few bothered to investigate the purpose. Building codes were introduced around the 1930s, and since then, homeowners have adhered to their requirements. Anyone who cared to build a crawl space used masonry blocks, if not poured concrete, and foundations were typically fitted with vents to the outside. 

HUD recommendations were that homeowners were to install crawl space vents and leave the ground uncovered. Codes also encourage homeowners to set up vents on adjacent walls. 

Venting was supposed to enhance ventilation and reduce moisture buildup. Unfortunately, these fixtures worsened the situation by encouraging moisture. The result was crawl space engendered health problems and structural issues. 

Sources of Air Leaks 

Many things can cause air leaks. Gaps in electrical and plumbing, floor/ceiling junctions, and the intersection of external walls. Ventilation ducts and your chimney are other conduits. Windows, doors, and wall sockets bring in air to your home too. 

In the past, homeowners had to abide by crawl space standards that required them to use ground cover together with ventilation. Things have changed, and builders have room to wiggle when controlling moisture. 

Dealing with Crawl Space Moisture  

Combining ground covers and air exchange has always been the accepted method of regulating crawl space conditions. Homebuilders recommend that you do the following: 

  • Seal your ventilation ducts and create air pathways 
  • Clear any surface water and install a vapor barrier  
  • Remove ineffective insulation and install properly functioning material 
  • Set your AC thermostat above the dew point.  
  • Enhance moisture removal by sizing your dehumidifier and maintaining it 

Avoid passive venting. Above all else, for persistent moisture problems, it is best to completely cover the vents as well as encapsulate your crawl space before conditioning it. 

Is Crawl Space Ventilation Useful?  

Study after study points to the fact that crawl space vents are detrimental to your home. They act as a conduit for moist and warm outside air. When this air floats into your crawl space, it’s likely to cause any of these problems: 

  • Crawl space condensation 
  • Mold and mildew growth 
  • Crawl space insulation damage 
  • Wood decay and rot 
  • Termites or pest infestation 

Research shows that a considerable portion of crawl space air ends up in the living space. But that’s not even the problem. The real issue is that venting has the potential to double the amount of radon gas in your home. 

If you’re lucky enough to escape radon poisoning, we’re not sure you will fare any better with musty smells and heating costs. Your only recourse is to seal the vents and condition your crawl space. Talk to your local contractor if you need help with choosing a dehumidifier. As well as lowering humidity, this appliance will prevent condensation and forestall mold growth. 

Why Seal the Crawl Space? 

There are many benefits of sealing the crawl space. One is sealing locks out air from the outside meaning moisture won’t build up and cause condensation or mold growth. You will also notice a significant improvement in air quality. The crawl space, which was once colder, will become warmer, as there’s little temperature variation. You won’t be running your heater as much, so the costs of heating will drop. And you will have a clean, dry space below your feet. 

As long as the vents remain open, it’s going to be an uphill task of trying to control moisture. Schedule a free crawl space repair inspection and quote with the experienced professionals at Foundation Repair of Western Colorado and find lasting fixes to your perennial moisture issues today. We will assess your home and the crawl space and advise you on the best way to tackle moisture.

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2401 SE Creekview Dr.
Ankeny, IA 50021

Kansas City Location

211 SE State Route 150
Lee's Summit, MO 64082
(816) 774-1539

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Moberly, MO 65270
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Springfield, MO 65803
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Fenton, MO 63026
(314) 207-9995