If you feel as if your house is never quite as warm as you’d like and you’re not sure why, the answer may lie behind your walls. Inadequate insulation for walls can be a key reason your energy bills are higher than you’d like. ENERGY STAR® says properly insulating walls can also help reduce outside noise; decrease pollen, dust and insects entering your home; lower the chance for ice dams on roofs; and help with humidity control.
Ideally, your home has a continuous barrier of insulation, from your attic all the way down to your basement and including all your interior and exterior walls. A coat, after all, isn’t as effective if it’s not zipped. Until the 1960s, though, standard wall insulation codes for homes did not really exist. This means that if you’ve got a home built before then, chances are good that your exterior wall insulation or interior wall insulation might be inadequate or even nonexistent if you live in a really old home.
Insulation is basically a coat for your house: It slows the flow of heat, ideally keeping more of it where you want it — either inside when it’s colder outside, or outside when you’d prefer not to melt in your home. Like a coat, the thicker (generally) the insulation, the warmer the house in the winter. A down parka is warmer than a thin fleece, right?
Before you decide whether or not you need to add exterior wall insulation or interior wall insulation, you’ll want to take a few other steps. Check for air leaks (which could include some easy DIY fixes to your leaky home). An energy audit makes sense, too, since that can illuminate other places where your home is letting energy escape.
Assuming you’ve determined a need for insulating walls, here’s what you need to know to get started.
While you are looking behind your walls to determine how much interior wall insulation or exterior wall insulation your house currently has, David Darling offers this plan to check your wall insulation in his Encyclopedia of Alternative Energy:
Now that you’ve got a sense of how much insulation your walls have, you’ll need to consider types of insulation and pay attention to R-value as you decide how to insulate walls. R-value is a number used to explain how much heat flow is restricted by a certain type of insulation. Different R-value levels are required for different parts of your home but basically the higher the R-value, the better your insulation. Energy.gov has a handy chart to see what kind of R-values your home should ideally have in different climate zones.
We have focused on how to insulate walls for existing homes rather than how to insulate walls on a house under construction, under the assumption that if you’re building a new house, you’re working with a contractor and architect who are going to inform you about best practices for insulating walls. Energy.gov recommends the following types of wall insulation for insulating walls:
So now you know more about insulating walls, including the types of insulation to use. Don’t forget the rest of your house’s “coat.” We’ve got you covered for attic insulation and basement insulation, too. We also offer insulation for light switches and outlets, a good starting point for insulating your walls.
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