Chris' Corner: South Simcoe Crawl Space Insulation "Do's and Don'ts"

South Simcoe Crawl Space Insulation "Do's and Don'ts"

Probably two thirds of the homes in Tecumseth Pines have crawl spaces, as do many older homes in New Tecumseth, Angus in Essa, and Adjala-Tosorontia communities like Colgan Everett, Rosemont and Lisle.

Cynthia Freeney, of Basement Systems Inc., in Seymour CT, shares some great "Do's" and "Don'ts" regarding Crawl Space Insulation.  Her post was written for Washington State homes, but her information applies equally well to South Simcoe.

If you are looking to buy and/or sell a home in Tecumseth Pines, New Tecumseth, or in any of the communities of Adjala-Tosorontio or Essa, call me Chris Smith @ 1.866.936.3500 for assistance in helping you achieve your real estate goals.

If you want to leave a comment for Cynthia, click on her link below:

Insulated crawl spaceWashington is one of the coldest states in the union, and the western portion also has some of the highest levels of precipitation year round.

For homes built on dirt-floored, vented crawl spaces, that mix of cold winter weather, and very high humidity year round can have a big impact on indoor comfort and energy consumption.

In fact, according to Advanced Energy, a nonprofit agency devoted to energy efficiency, energy losses through unimproved crawl spaces  are so significant that homeowners might as well put aside any other attempts to improve energy efficiency, until the crawl space is fixed.

A properly insulated crawl space is, therefore, one of the main components of a green, energy efficient home.

For crawl space insulation  to be effective, it needs to be selected and installed properly. There is still a lot of misunderstanding concerning proper treatment of crawl spaces.  While recent studies and years of crawl space disasters point to the inefficacy of  things like open crawl space vents and fiberglass insulation installed between floor joists, many general contractors are still doing things the old way. The folks at CleanSpace Northwest have been successfully treating crawl spaces in Greater Olympia, Port Angeles, Bainbridge Island, and surrounding areas for a number of years, offering solutions developed according to cutting-edge building science findings.   They know what works and what doesn't.

The following are some “Dos and Don'ts” of crawl space insulation, from yourNorthwestern Washingtoncrawl space environment experts.


Don't insulate without sealing air leaks.

Insulation's role is to prevent conductive temperature transfers between the outside and the crawl space. Insulation alone will not prevent temperature changes due to air leakages.


Do: Air seal or encapsulate the crawl space.

Crawl spaces are especially prone to air leakages due to a physics phenomena know as the "Stack Effect". Heated air inside the building rises and escapes through the upper levels. As a result, a low  pressure area is created in the lower portions of the building, causing new, unconditioned air to be sucked in through the basement or crawl space. This is why, having the crawl professionally air sealed, or encapsulated, is so important if the goal is to improve energy efficiency.

falling wet fiberglass insulationDon't insulate a vented crawl space by placing fiberglass between the floor joists.

It might come as a surprise to many that this popular and inexpensive method of crawl space insulation is not only ineffective, as it can be downright disastrous.

Fiberglass insulation is the worst possible choice for a crawl space (or any below grade application). For it to be effective it needs to be evenly spread, and loose with as little gaps in the blanket as possible. That alone is difficult to accomplish when applying batches in a tight crawl space with so many joists, pipes, ducts, wires, etc... 

Also, fiberglass is only effective if completely dry. Vented, unsealed crawl spaces are humid year round. The fiberglass will soak up the moisture, sag and create voids (empty spaces) in the insulation blanket. When fiberglass gets damp it also gets heavy enough to fall out of place.. Wet or damp fiberglass loses all its R-Value, becoming useless as insulation and, to make matters worse, the paper and the adhesives commonly used to hold the batches together are known to support mold growth.

In a vented crawl space, fiberglass also attracts rodents and other pests, providing warm and fluff shelter.


crawl space insulation systemDo: Encapsulate the crawl and insulate walls and floor with foam board insulation.

The best crawl space insulation method consists of a combination of vapor barrier and foam board insulation. Walls are lined with rigid foam board, and the dirt floor is covered with a thick (20mil) liner, which is then overlapped over the foam a few inches and sealed. All the seams are then sealed and caulked, and the crawl space is then conditioned with a dehumidifier.

If you live in Washington and need help figuring out what are the best options for your crawl space insulation, please contact CleanSpace Northwest for your free, no-obligation, in-home evaluation and let them show you how to transform your moldy crawl space into clean, lean and mean energy efficient machine. 

Chris Smith CSSBB
          Sales Representative

Interested in Buying or Selling Real Estate?

  ph: 1.866.936.3500

Chay Realty Inc.,

Comment balloon 0 commentsChris Smith • October 04 2011 02:16PM