Five Home Winterizing Myths
It is time to start thinking about getting our homes ready for winter. Maintenance and repair work done while the weather is still mild will pay off not just in the coming cold weather, but with year round benefits. Here are five common issues to think about when considering your winterization projects, and how to avoid making some common mistakes while improving your house.
Window film insulates windows. False.
A window film serves as a draft barrier to stop air leaks, rather than effective insulation. The plastic film itself will contribute very little. Having another air layer is more helpful, and keeping moisture sealed out can help reduce frost forming on old windows. But if you have big windows that are losing lots of heat, a quilted curtain can be more helpful. Windows are big thermal holes in your walls, and even very efficient windows lose heat much faster than the walls that support them. A window film adds only a slight increase, but it can be effective for stopping drafts.
Stuff more insulation into a space to make it tighter. False.
Fiberglass insulation works by keeping the air in the space between studs from moving. But the insulation itself can be a heat conductor. Cramming more insulation into a cavity pushes the fibers together, increasing their surface contact and increasing the heat transfer, rather than decreasing it. In attics, even when it is at the proper thickness, insulation needs to be kept away from the underside of the roof deck in order to allow proper airflow for ventillation.
Every house gets icicles on the roof. False.
Once there is snow on the roof, it should stay there. If your roof is melting and you have lots more icicles than your neighbors, that’s one sign that you may have inadequate insulation in your attic. Because heat rises, attic insulation can have a more significant impact than wall insulation. And, as long as the attic space is even moderatel accessible, it is far easier and less expensive to add insulation to the attic than it is to add it to exterior walls. Just be certain not to block the necessary airflow to keep the underside of the roof properly ventilated.
Sealing all the air leaks will make my house too tight. Mostly false.
Some recently built houses may be super-tight, but the vast majority have plenty of air leaks. In addition to caulking windows and doors, check other penetrations in the exterior of the house to make certain they are air tight as well. On the interior, check outlets, light fixtures, and other penetrations in ceilings and outside walls. These can be sealed with inexpensive foam gaskets that go behind the switchplate to keep the drafts out.
I can’t insulate my walls. Mostly false.
A variety of methods can be used to insulate walls in older homes. Spray applied or blown in insulation can be installed in most any kind of cavity wall. Old, loose-pack cellulose insulation may have settled and need to have additional insulation added. But existing walls can be filled with insulation. The technology to fill concrete block (CMU) cores with insulation is even available for commercial projects (it’s likely to be too expensive yet for the average single-family residential project yet).
Other measures we have discussed before, such as having a home energy audit, can also help evaluate your home’s efficiency and can help find the key areas where repairs or upgrades can make the biggest contribution to improving your energy use.
Image Source: Natasha2006 via Wikimedia Commons
Applying sealant/caulking to outside gaps around windows and doors stops drafts and keeps cold air from getting as well.
Absolutely true, Brian. But there are gaps in many operable windows that cannot be caulked. Older double-hung windows may have gaps at the sides or at the meeting of the two lites, for example, that one would not want to caulk and that cannot be easily and securely weatherstripped.
There are removable caulk tapes that can serve similar purposes. And storm windows can also cut down on the associated problems, as well.
There are many good steps that can (and should) be undertaken.
Window film insulates windows. True.
A draft is by definition cold air sinking fast, so if you don’t have a draft you have insulation. In fact, putting on the film (I am talking about the stuff that shrinks when you heat it with a hair dryer, not film that is put right on the glass) creates an air space with an R value of 1 and two surfaces with an r each of .16, totalling 1.32. since a single glazed window is R .96, putting on film more than doubles the R value.
I can’t insulate my walls. Mostly false.
If you have an old house like mine with 8″ of brick, 3/4 inch strapping topped with lath and plaster there is nothing you can do. the plaster breaks the voids up and trying to put any kind of foam in just pushed the old plaster right off the wall. I have tried it, there is nothing you can do.
“Older double-hung windows may have gaps at the sides or at the meeting of the two lites, for example, that one would not want to caulk and that cannot be easily and securely weatherstripped.”
I go through two tubes of removable caulk per season on my 100 year old doublehungs and it pulls off like a dream in the spring.
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