Crawlspace question

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Posted by: from Toronto
7/17/2018 at 9:27:26 AM

We have a small crawlspace in our basement (closed off from the rest of the basement) which has a dirt/soil floor and it is currently covered with a plastic sheet. We were told that it is not good to keep that sheet there as it can cause moisture issues but another friend told us that we should have this sheet there to prevent the soil moisture from seeping into the rest of our house through the air. Not sure which is the correct way to keep that space which we do not use. Also, our area is prone to termite/pests so we want to keep that space clean and pest free.

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Date/Time7/17/2018 at 10:07:27 AM


Is the crawl space heated area?

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Date/Time7/17/2018 at 10:54:22 AM

Hi Kay,

Your one friend is coming, keep the plastic there. If you choose you can even replace the plastic with rigid insulation this will help keep the space warmer in the winter months and cooler in the summer months. However, moisture build up is only a problem when there is no air movement. Your crawlspace is vented out the sides (or should be, if not you need to do this) creating the airflow and allowing moisture to vent. This is why the space does not smell of mould and mildew. If you start smelling that, you're going to want to make sure ventilation is not blocked off or if it isn't you can add an extraction fan to one of the vents to assist in air movement.

Hope this helps.

- Tim

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Date/Time7/17/2018 at 12:58:09 PM

Hi Kay, I would recommend leaving the plastic covering the soil or even better bye a proper soil covering sheet. The most important thing is that your crawl space is vented from two opposite sides tool all boister Xscape it will also keep the floor above warmer in the winter cooler in the summer. The best way to to ensure that insects to. Get up through your floor is to spray for a 2 lb spray foam insulation. You can also cover the underneath side with a plywood if the sprayfoam insulation is too expensive, it's not an expensive that's for sure. Make sure it's vented Kay! Jeff

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Elbert from GTA Basements 416 in Innisfil
Date/Time7/23/2018 at 10:01:50 PM

Please, dont take the plastic away from the soil, it will create severe problems of Mold in the crawlspace.

Best regards,


GTA Basements 416

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