Spray Foam Insulation

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Solving Crawlspace Problems in Winnipeg


Depending on where you live, critters from snakes and rodents to spiders, bugs, may have taken up residence in your crawl space. Add a little water—or even a lot when flooding occurs—and mold and rot create indoor air quality problems and structural deterioration. Oh, and did I mention that soil gases like radon or methane can find their way into your house through the crawl space? Research has shown that whenever it’s warmer inside your house than outside, the buoyancy of the rising warm air in the house sucks air into your home from the lowest point, often that's the crawl space.

Historically, most crawl spaces have been vented to the exterior. In some climates—especially with the introduction of central A/C—this can cause problems. In climates with extended periods of hot-humid weather—closed crawl spaces are the best option. Under hot-humid conditions, warm, moist air enters the vented crawl space from outside and can condense on the cooler surfaces. These cooler surfaces are created within the crawl space by the shade provided by the building and the moderating effect of the contact between the crawl space and the ground. Even when condensation doesn’t take place, relative humidity (RH) above 80% for an extended period can support mold growth and eventually rot wooden structural materials. Add A/C to the house, and the floor above the crawl space becomes even cooler—and any ductwork in the crawl space creates an added risk of condensation.

At Red River Spray-On we specialize in closed crawlspaces. In closed conditioned crawl spaces insulation is normally placed around the perimeter and not in the floor. With perimeter insulation the house is coupled to the cooler temperatures of the ground, and this can reduce the overall amount of A/C needed to cool the space above. When closed conditioned crawls are used in heating-dominated climates life Winnipeg, this same ground coupling can actually increase the heating load of a house, but that may cost very little compared to the cost of damage done by moisture brought in by venting. To help reduce the heating load in winter and to additionally control the relative humidity we add a thick continuous air and vapor barrier on the ground seal it to the perimeter wall with gets sealed and insulated with 3-4 inches of closed cell spray foam insulation.



1. Crawlspace vents are not necessary

A Sealed and Conditioned Crawl Space is the best solution to reduce air infiltration. A sealed crawl space is achieved when you eliminate all vents in the crawl space which stops all outside air infiltration to the crawl space.

2. Sealing off the dirt floor is important

After you eliminate the venting of the crawl space you now need to seal the crawl space floor (skip this step if your crawlspace has a concrete floor) from the crawl space area. This seal normally consists of a moisture/vapor barrier installed on the crawl space floor and sealed to the crawl space wall to keep the moisture from the soils down below the barrier.

First, a 15 mil vapor barrier will be laid on the crawl space floor. The vapor barrier will extend between 6 to 12 inches up the crawl space wall. The vapor barrier will then be ramset with concrete nails into the concrete block crawl space wall. You can also use an adhesive this is just to hold the poly in place so we can permanently seal it the wall with spray foam

3. Now lets condition the air

Next we need to condition the crawlspace by adding current heated or cooled air from the heating/cooling system directly into the crawl space. This keeps the temperature of the crawl space very consistent and close to the interior tempter of the home, regardless of the season. This helps reduce moisture build up on the duct work, reducing humidity levels, and allow the heating and cooling system to supply air flow through the duct work in the same temperature it will be received in the interior of the home.

4. Now comes the most important part

Next we need to insulate the parameter walls thus creating a mini basement. The crawl space walls will then be sprayed with Spray Foam Insulation by Red River Spray-On's expert and fully trained applicators by adding approximately 3 to 4 inches or R19-24 from the crawl space floor area to the top of the crawlspace Rim Joist. All areas where the floor vapor barrier laps onto the wall will be completely sealed thus sealing off the floor as well.

Here's what we accomplished.


• We eliminated air infiltration by sealing the walls, vents, and rim joist

• We eliminated heat loss through conduction(heat transfer) by applying at least 2 inches of spray foam insulation to the perimeter walls

• We eliminated moisture intrusion by laying the vapor barrier on the crawl space floor

• We conditioned the crawlspace area by supplying the now un-vented area with conditioned air thus eliminating humidity, condensation, mold and rotting floor boards

• The conditioned space also creates energy efficiencies by allowing the air ducts to operate at a constant temperature

• The Sealed Conditioned Crawl Spaces Saves you money and eliminates all crawlspace problems