The home we just bought has a dirt floor for a crawlspace, should we do something about it?

Q:

The home we just bought has a dirt floor for a crawlspace, should we do something about it?

A:

Dirt floors (in crawl spaces) are a common occurrence for homes built 30 or more years ago.
Today homes that are newly built have to have a vapour barrier protection installed on top of the dirt that makes up the floor of a home’s crawlspace, this in the building code.

Older homes that don’t have this vapour barrier can have the following problems;

• Mold or mildue forming in the crawlspace on the bottom of the floor joist or on the concrete foundation walls.

• You can have problems with the flooring on the first floor of your home above the crawlspace. These problems can consist of popped tiles; wood floors that heave or a rotting of the sheeting/subfloor.

• If your furnace is situated in the crawlspace then the moisture can be circulated throughout the entire home.

• The furnace can be damaged by the moisture around it; if the moisture is excessive then it can cause corrosion to the metal parts and the electronics inside the furnace.

• Without any protection on the dirt floor you can have living organisms like rodents or bugs that take up residence, there is nothing to stop them from tunneling in and around. This can cause odors and other problems with rotting carcases and waste.

Vapour barrier isn’t the only thing that you can do in the crawlspace to prevent moisture. A lot of homes built in that era do not have any insulation in their crawlspace at all; other homes have insulation that is placed in between the floor joist above the dirt floor. This insulation is usually older cheaper batte insulation and is usually prone to falling out onto the ground below. A lot of insulation companies help solve this problem by spray foaming the entire crawlspace, the floor and the walls.

This gives you an insulated seal that works as a vapour barrier as well. The insulation also will lower your energy bills and help make the floor of your home warmer on the feet.

Another way to control the moisture is to pour a concrete floor down there in the crawlspace. This is not a cheap option as it is labour intensive but it does help stop the excessive water that sometimes makes it into crawlspaces from the spring melt. It also gives you an area that you can now store things safely and have equipment placed their (furnaces or boilers) without the fear of damaging the insulation or vapour barrier.

There are companies that specialize in this sort of thing; they have speciality products that are like a glorified pool liner that is installed over the walls and dirt floor of the crawl space. The product is very strong and has a very good warranty; it works very affectively to stop moisture and organisms from getting into the crawlspace.

Whatever way you choose to do it, doing something is better than not doing anything at all. Overtime moisture can damage a lot of the home without you even knowing it’s happening. Take the time and do it right so that in the future you will not have any problems.

Rob Abbott
Village Builders Inc.