Spring is finally here. Without a doubt there were a few times during cold snaps this winter when you were reminded of the places in your home where the cold air is creeping in and creating drafts. Check out our handy home insulation guide for advice on how to get started.
Home insulation basics
Let’s go back to the basics of what insulation is and what it does. Every construction product used in your walls and roof has an R-value. R-value is a measure of thermal retention. When you think of your home, the insulation in the attic is intended to keep the warmer air in your home from warming the attic or being conducted through the ceiling to the attic. The higher the R-value a product has, the more resistance it has to heat loss through conduction. Pretty basic stuff. The problem in some homes is not how much insulation it has, or having enough, or having a high R-value, or the right R-value. Sometimes you need to go back a little further and address air flow in the space.
The point of adding insulation in your home is to retain heat and minimize heat loss. However, even the best insulation is no match for air leaks in your home. Warm air rises, up through your ceiling and roof, leaving space for cooler air to come in. Your insulation, as great as it is, cannot stop air flow and heat loss due to air leaks.
There is no right or wrong time to add insulation or plug air gaps. In fact, working in an attic is going to be a lot more comfortable while it’s cooler outside.
Where to begin
You can start with simple steps and move on to larger projects over time. Some of the places where air is coming in are going to be obvious. You may feel cooler air coming in around outlets and switch plates. These are areas where the insulation in the wall may have gaps. Spray foam insulation can be used to fill the voids around electrical boxes. Other areas in your home that may need attention are the frames around windows and doors. Stopping air flow at these points may be as simple as adding new weather strip to a door or adding heavier curtains or drapes at the window. Caulking windows and doors around trim can also prevent air leaks. Caulking can be done on the exterior when the weather is milder, and on the inside at any time.
For insulation batts, pay attention to the installation instructions from the insulation manufacturer. Johns Manville offers a series of videos on using their insulation products, check out this playlist on our YouTube channel:
Remember, insulation all by itself is not the key to keeping your home warmer or reducing your energy use. The job of insulation is to reduce heat loss in the winter and reduce heat gain during the summer, keeping you more comfortable all year long. Keeping your already-heated (or cooled) air from seeping out through air leaks and gaps will help you to be more comfortable and will allow you to feel the results of a properly insulated home. As an added bonus, you may see a difference in your energy costs year-round as well.
The US Department of Energy explains it on their site https://www.energy.gov/energysaver/weatherize/insulation:
“Regardless of the mechanism, heat flows from warmer to cooler until there is no longer a temperature difference. In your home, this means that in winter, heat flows directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors–wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house.
To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.”
Here’s what you can do
The Department of Energy also provides these tips for sealing air leaks in your home, an important first step to reduce the air flow of your heated or cooled air:
- Test your home for air tightness.
- Caulk and weather-strip doors and windows that leak air.
- Caulk and seal air leaks where plumbing, ducting, or electrical wiring comes through walls, floors, ceilings, and soffits over cabinets.
- Install foam gaskets behind outlet and switch plates on walls.
- Inspect dirty spots in your insulation for air leaks and mold. Seal leaks with low-expansion spray foam made for this purpose and install house flashing if needed.
- Look for dirty spots on your ceiling paint and carpet, which may indicate air leaks at interior wall/ceiling joints and wall/floor joists and caulk them.
- Cover single-pane windows with storm windows or replace them with more efficient double-pane low- emissivity windows. See the Windows section for more information.
- Use foam sealant on larger gaps around windows, baseboards, and other places where air may leak out.
- Cover your kitchen exhaust fan to stop air leaks when not in use.
- Check your dryer vent to be sure it is not blocked. This will save energy and may prevent a fire.
- Replace door bottoms and thresholds with ones that have pliable sealing gaskets.
- Keep the fireplace flue damper tightly closed when not in use.
- Seal air leaks around fireplace chimneys, furnaces, and gas-fired water heater vents with fire-resistant materials such as sheet metal or sheetrock and furnace cement caulk.
Looking for great insulation product for your home? We have a variety of insulation products for different uses, including fiberglass batts from Johns Manville, mineral wool batts from Rockwool, spray foam insulation and more. For rigid insulation, try DOW TUFF-R . It’s easy to handle and can be applied to a variety of surfaces. Read our previous blog to see how you can use this high-quality product!