What You Do NOT Want to See in a Crawl Space

It’s expected that the real estate market in southwestern Ontario will continue the current upward trend. We know that it’s a great place to live, work and play… and others are discovering our part of the province as well!

If you are a realtor, or in the market to buy or sell, we would like you to be informed about a critical feature of a home: the crawl space.

Here are six things that you do not want to see in a crawl space. It impacts the home; the structure, its health, its enjoyment and the future value.

Crawl Space before and AfterUnsealed vents – Unsealed access or vents to the crawl space is the first sign of a problem. Many people believe that vents allow airflow to condition the space below a home, but in reality, open or unsealed vents allows the outside air to enter the home. Cold air enters in the winter, and hot, humid air enters during the summer. This outside air creates condensation and humidity problems which can result in higher heating and cooling costs, mould growth, wood rot and musty smells throughout the house.

Bugs or critters – These unwanted houseguests are a sign that the crawl space is not sealed correctly. If bugs and critters can enter, so can the outside air!

Evidence of water penetration or damage – Muddy areas, rotting wood, efflorescence on concrete walls or floors and mould are all signs that water is damaging the crawl space. 

Falling insulation – Fibreglass insulation that has dropped to the floor of the crawl space is a sure sign of a humidity problem. The damp air soaks the insulation, causing it to fail, fall and become completely ineffective.

Vapour barrier on the underside of the floor joists – If you see a vapour barrier on the ceiling in a crawl space, enclosing the floor above, this is a big no-no! This barrier traps moisture and significantly accelerates wood rot.

Dirt or concrete floor – Dirt naturally holds moisture and concrete is porous – both which allow water to penetrate and become a source of moisture and therefore humidity in a crawl space.

Advanced Basement Systems Service Area

What do you want to see in a crawl space?

A completely sealed space!

-        Sealed vents

-        A professionally installed and heavy-duty vapour barrier which is sealed and encapsulates the floors and walls.

-        Insulation that is effective and moisture resistant

-        An acceptable humidity level

If you have any questions or concerns about a crawl space, whether in your home or a home you are looking to purchase, we would be pleased to help you. We proudly serve all of southwestern Ontario.

Please reach out to us anytime by phone: 1-866-277-1277 or online by clicking here

About the author

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Ben Bates
Ben Bates lives in the Chatham-Kent area and has been involved in the basement, crawl space and foundation industry since 2008. He has a passion for improving homes the right way and knows what it takes to waterproof, encapsulate or stabilize homes in Ontario. He assists with over 900 projects per year.

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23576 Prince Albert Road
Chatham, ON N7M 5J7
1-226-706-2439


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199 Exeter Rd Unit E
London, ON N6L 1A4
1-226-271-8708
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