Since the early 1970s, people living in cold-weather climates realizes that a lot of heat escaped from our homes during the winter because homes weren't properly insulated. That gave rise to companies that produced fiberglass batts (sheets of insulation) that had to be meticulously installed in homes. Now, there are several insulation products on the market that simply have to be blown into attics and walls. As with nearly all products, though, there are drawbacks.
Insulation is graded by an R-Factor, where the higher the number, the greater the thermal performance of the insulation. For example, you can expect to have an R-factor from 3.1 to 4.2 per inch of rolled insulation, where an inch of blown-in fiberglass yields from 2.3 to 2.8 per inch. That means you must inject 50 percent or more of the blown-in product to achieve the same performance as batts of insulation.
Let's say that you want to convert your attic to a usable space. If you've used rolls of insulation, it's only a matter of pulling the material away from the ceiling or walls. However, it's far more difficult to remove insulation that's been blown in. Considering you must use more inches of the blown-in variety, your difficulty is compounded.
As time passes, blown-in insulation will settle and the result is reduced performance. And because you must use more of it than batting, you'll also run the risk of the plaster or wallboard sagging below where you've blown in the insulation.
You'll need to seal around electrical junction boxes and plumbing because, otherwise, you'll be plagued by inhaling the tiny particles of the insulation that manage to make it down to the living area of your house. While the long-term effect of breathing those particles is unknown, it can be an irritant, according to the Blown Insulation website. In addition, if you need to get to that plumbing or electricity, you must first remove all the blown-in insulation. Then, when you're finished, you'll need to reapply insulation to the area.
Do It Yourself Blown-In Wall Insulation
Fiberglass, cellulose, or mineral wool insulation can be blown into your walls between the studs to provide extra insulation in your home....
How to Remove Blown-in Insulation
Blown-in insulation is composed of small clumps of cellulose loosely packed in your attic. Sometimes, it may become necessary to remove the...
The Disadvantages of Fiberglass Windows
Replacement windows are a considerable expense for the average homeowner, so deciding which type of frames to use should not be taken...