The Proper Way to Insulate Your Crawl Space
Posted on: Mar 14, 2011 Category:Insulation
Problem: Cold Crawl Space
In any heating climate (climate that experiences winters like here in Ann Arbor MI.) it can be very cost effective to insulate crawl spaces. A crawl space is an area under your home that varies from about 15” deep upwards to 4ft deep. The crawl is usually sealed (or so we think) with an access door in a basement, outside, or even a floor hatch within the house. It is cold, dusty, moldy, and sometimes even wet. Crawl spaces are nasty buggers! The crawl often spans an addition or sometimes the whole home is on a crawl. In homes such as these homeowners often complain a particular room is very cold and drafty or that the floor itself is very cold. Sometimes they notice the walls in such a room are very cold also. In a situation such as this it would be a good idea to retrofit the crawl space with insulation.
The old school method done by handymen, unknowledgeable builders, or the homeowner themselves was to place batts of fiberglass insulation inside the crawl. Often it is placed on the walls or just thrown on the floor. Both methods are wrong and hazardous to your health for several reasons:
- It does not allow for the moisture factor involved with exposed earth.
- It allows for the growth of mold and mildew which is then transferred through interstitial spaces (walls, rim joists, floors, etc) and of course so is the cold.
- It allows deadly radon gas to enter the home.
This is not a job I recommend a homeowner do themselves. A trained energy specialist should undertake this job because of the air quality issues, moisture and mold issues, and of course energy efficiency calculations involved.
Solution:
Crawl Space and Foundation insulation should be done if the vents can adequately be sealed off. The best product to use under these conditions should be true closed cell, fire retardant, vapor barrier foam. Crawl space sealing should be done with a true continuous ground vapor barrier applied to the floor of the crawl and slightly up the wall. The vents should be sealed. Any duct work within the crawl should also be sealed and insulated with a fire rated foam. Finally all rim joists should also be sealed. This method usually will pay itself back within a couple of year. If done by a professional the room above the crawl will usually become instantly warmer. More importantly the air quality of the home is dramatically increased; thereby reducing asthma causing pollutants and deadly radon gases from being transferred into the home. Save energy, increase air quality, prevent future water issues. This is a no brainer when it comes to retrofits. However, please deal with an insulation specialist! I have seen several handyman jobs that actually cost the consumer quite a bit of money to fix, not to mention the air quality issues they and their families face a few years after their project is finished. Don’t be that person. Please contact us for more information if your home is experiencing any of these issues. We can help!
April Rue, President
Ms Green Construction
