Sealing Air Leaks in Exterior Walls – Energy Saving Project

Energy Saving Projects

Sealing Air Leaks in Exterior Walls

This is one of the simplest energy saving projects you can tackle this weekend. By sealing up penetrations in your home’s exterior walls,  you’ll help prevent air infiltration into and out of your house.

Energy Saving

Little gaps like these are like ants – one won’t bother you, but a whole bunch can ruin a picnic. In this case, if you add up all the gaps in your home, it could be like leaving a window open all year!

If you look around the outside of your home, you’ll likely find electrical conduit and pipes coming out of the walls somewhere. The small gaps and spaces around those protrusions are a prime source of energy loss. They can also allow insects and critters inside!

The Solution:

The easiest way to help alleviate this problem is to use expanding foam to fill the voids. It’s sold commercially under several brand names, including Dow’s Great Stuff. The trick is to buy the right product for your situation. For this project, we’re using the type that’s meant for small cracks and gaps.

Energy Saving

Be sure to get the right foam for your project. Make sure you read all the directions and warnings, as well. (from our crack legal team)

Step 1:

Fill the gap slowly, and be sure to get the foam around all sides of the pipe or conduit. It will begin to expand pretty quickly, so stay alert and stop spraying the foam as it begins to overflow slightly. It will continue to expand.

Energy Saving

Be sure to wear gloves and old clothes, because this foam is one of the stickiest substances known to man! I have a tip for that below…read on.

Step 2:

Once the foam has hardened (which varies but is usually less than an hour), use a utility knife to remove the excess.

Energy Saving

A sharp putty knife or hack saw blade (without the handle) work well, also.

Step 3:

Once the excess is removed and you’ve scraped off the residue, you can paint it to match the surrounding area. I’ve used small wood covers like the one below to further seal up the area and conceal the rough edges.

Energy Saving

You can make a backing plate to cover up the area once you’ve sealed it, if there’s room. Use pressure-treated wood or a piece of aluminum to avoid rot and corrosion.

You’re Done!

It may not seem like a big deal, but if you take the time to fix these small problems, you could start to see the energy savings add up.


Once you start using the can of foam, it’s a good idea to use the entire contents. While it’s possible to clean out the spray tube and nozzle, it can be a difficult and messy job. The most economical way to tackle this project is to identify all the gaps around your home and complete them at the same time.

As I mentioned above, the expanding foam is extremely sticky on just about any surface. It’s a good idea to have a package of these hand wipes for clean-up afterward. You can read more about them, and see them in action in my review HERE.

Great Stuff Wipes

These wipes are effective and inexpensive. You can find them on Amazon for about $3.00/package of 30.

There are plenty more tips and projects like these in my book, Spend a Little, Save a Lot Home Improvement. Hey, look – you can buy a copy right here! It’s just $20 and I’ll even sign it for you – what a deal! Just click the secure link below and the magic happens. Limited supply, though, so don’t delay 🙂

Spend a Little Save a Lot Book

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Brad Staggs

Contributing Writer/Producer at Tool Skool
Brad has worked in and around the home improvement and tool industry most of his life. He was host of Talk2DIY Home Improvement, Co-produced DIY Tools & Techniques and is the author of Spend a Little, Save a Lot Home Improvement.