Open Crawl Space

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What is an open crawl space and why does it need to be “fixed”?

A typical open crawl space has open foundation vents and an exposed or partially covered dirt floor.

Open Crawl SpaceThis type of foundation construction is very common throughout the United States and Canada.

Reasons a home is built on a crawl space

There are several reasons a home is built on a crawl space instead of a basement or a slab foundation. The two major reasons are cost and ground water problems.

Ground water problems

An area that has a high water table or is near a lake, river or canal will have little choice but to explore a crawl space foundation or a slab to build a home on. Basements most often are not an option unless they are located on high ground due to the dept of the foundation required to build a basement.


Another reason homes are built on crawl spaces is because it is cheaper. Most crawl spaces are only 20? to 36? to the bottom of the home floor joists. Compared to a basement which has an average height of 8', there is much more work and expense involve in making the foundation 5-6' deeper into the ground for a basement. Although homes on a crawl spaces are less expensive to build they are more expensive to heat.

Open crawl space problems

The list of problems associated with an open crawl space goes on and on. For all homes built on a crawl space there are similar problems but always one or two major reasons to get it fixed. What we hope to do here on our website is to alert you to what else might be going on under the floor and help you find a solution that won’t break the bank.

There are five major problems with six common symptoms and four distinct causes to the negative issues associated with the open crawl space environment.

To help you better understand what is going on in the crawl space you have to first separate the real problems from the symptoms. Once you understand the problem you can fix your crawl space instead of medicating the symptom.


  • Odor
  • Mold/Mildew/Fungus
  • Wood Boring Insects- i.e. Termites, Powder Post Beatle, Carpenter Ant
  • Structure Rot
  • Cold Floors
  • Moisture
  • Foundation Vents/Outdoor Accesses
  • Foundation Walls
  • Gaps Around Sill Plate and Rim Joist

What does this all mean?

Although many homeowners see the symptoms listed above as the real problem, but actually are not. Like any part of life, fixing a symptom will only gain short term results and with a crawl space it may end up causing more problems. By identifying the real problems, as listed above, we are able to find the cause.

Take odor for example, there are two factors that increase odor, heat and moisture. A dead animal on the side of the road does not smell as offensive in the winter as it does in the hot summer. A dog might not smell bad when he is dry but if he gets caught in the rain he will smell like a wet dog and that’s usually not pleasant.

The point I am trying to make is if you fix the cause of the problem, the symptoms go away. It is easier and less expensive than you may think to get these problems fixed as a DIY Project. It is however, a bit more complicated that just putting down plastic. Keep in mind this project is just as much about what not to do as it is about what to do.