How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power

How Do I Air Seal My Home to Improve Energy Efficiency?

Thinking about some Do-It-Yourself (DIY) home improvement projects for your Texas home, but you’re not really sure about what to do or where to start? You’ve come to the right place! Welcome to the DIY Energy Efficiency Tips series from First Choice Power. We’ll show you how to improve the energy efficiency of your home, including hints that make the jobs easier.

What is Air Sealing?

At its most fundamental, “air sealing” your home means keeping the outside air outside and what’s called the “conditioned” (heated or cooled) air inside. By reducing drafts and other places around your home where air leaks in and out, you reduce the amount of energy you use to keep the air inside your home dry and at a comfortable temperature. Finding and sealing drafts throughout your home can reduce your energy consumption and bills by 25%.

Outside Your Home

It all starts by seals around the places where wiring or plumbing passes through exterior walls. This includes:

How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power
Tighten those screws, and make sure air can’t get behind that connecting plate against the house.
  • Wires or conduit for your home’s electrical service;
  • Hose spigots; and
  • Outside condenser for central air conditioning.

For outside outlet boxes, turn off the circuit breaker for these outlets and remove the outlet. Use caulk or expanding foam to seal where the supply wire enters the wall. Reassemble the outlet.

If your older home has concrete block foundations, seal any cracks or gaps with masonry caulk. You can also repoint with mortar, but while repointing is easy, it does take some time and technique.

Look for gaps at the mudsill and joist band. This is where the foundation meets the wooden framing for the house. Sealing here not only eliminates drafts, but it also seals out insects and rodents. If you find signs of rodents getting in in this area, either fill the gap with an expandable foam formulated with a bitter tasting pest-blocker (such as denatonium benzoate) or use mortar/masonry caulk.

How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power
You see that white caulk around the edge of this dryer vent? This homeowner is doing it right.

Seal around the dryer vent and make sure the vent actually seals. If it doesn’t, consider installing a self-closing dryer vent such as one made by Lambro or Heartland. Both vents open like a valve when the dryer is blowing out air but close off the vent tubing when the dryer stops running.

For older homes built before 1980, caulk around windows and door frames. Home construction before this era usually did not seal around windows when they were installed.

Inside Your Home

One of the biggest and most common areas for drafts is where the mudsill and joist band meets the foundation. Cold or hot, humid outside air can easily penetrate here and enter the conditioned living space. Keeping the joint sealed goes a long way to reducing drafts that contribute to your home’s stack effect.

How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power
Ready to ascend into your attic?

The attic is the other major important area to seal. Warm air rises through gaps for wiring, plumbing, and recessed lighting fixtures in your ceiling, enter your attic, and leave your home. This movement will also pull in cold air through drafty gaps at the mudsill joint, doors, windows, and other unsealed parts of your home. By filling gaps and sealing joints with caulk and expanding foam, you can greatly reduce drafts and energy loss.

If you plan on adding insulation to your attic, be sure to air seal your attic first because it’s much, much easier to do when there’s little or no insulation as opposed to when there’s 8 inches or more.

How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power
Hooray for safety in your DIY home improvement project!
  • Bring a 2’ x 3’ piece of 3/4” thick plywood to put across the ceiling joists so you’ll have something to kneel on while you work.
  • Wear knee pads, a filter mask, and a take a reliable flashlight with you, especially if your attic doesn’t have adequate lighting.
  • Start with the areas with the biggest gaps. The soil stack or sewer vent pipe usually emerges into the attic through a wide hole so fill this in with expandable foam. You can also add in pieces of rigid foam for larger gaps. Other common things to look for are the tops of wall joints (called top plates).
  • Seal around wires and pipes that emerge through holes in the top plates. Some experts recommend that the top plate be foamed over because, during construction, sheetrock installers typically leave an expansion when they install the ceiling drywall. It’s not very wide, but if you have a 10-foot long wall, the open space from a half inch wide gap can create a significant draft.
  • For some DIY homeowners, foaming over the entire top plate may not be practical, but sealing the long gaps with foam will make a difference so keep your eyes open.

Recessed can lights can be sealed by using a heat and fire resistant cover. To further avoid any heat-related problems, use cool-to-the-touch LED bulb in these fixtures. Drop soffits and similar structures that hang down below the ceiling surface should be insulated and then sealed over from above in the attic to prevent air movement. Likewise, open stud cavities should also be insulated and blocked over.

If your home has a brick or metal chimney and flue, you’ll need to block air flow around the chimney with aluminum flashing and use high-temperature silicone caulk to seal it. Do not use expandable foam! A heat shield to protect insulation can be fashioned using aluminum flashing to wrap around metal chimneys or flue as long ,as it provides a 2 inch or more gap between the insulation and the flue.

Sealing Windows and Doors

How Do I Air Seal My Home to Improve Energy Efficiency? | First Choice Power

Homes built in the last ten years tend to have better sealed windows and doors. However, dirty and torn weatherstripping prevents doors and windows from closing snugly.

  • The easiest thing to do first is to look inside of the door and window jambs. Check to see if you can close a piece of tissue paper in a door or window and still pull it out. If you can then cold air is entering.
  • Add weatherstripping as needed to help provide a snug seal.
  • On older, single-pane windows, be sure to check for loose window panes and crumbling glazing as these indicate the window needs some work.
  • For some windows, especially those that face north, you might even want to consider covering the window with plastic sheeting on the outside.

In the next installment of DIY Energy Efficiency Tips, we’ll talk warmly about insulation.

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About 

Vernon Trollinger is a writer with a background in home improvement, electronics, fiction writing, and archaeology. He now writes about green energy technology, home energy efficiency, the natural gas industry, and the electrical grid.