Finding and Stopping Insulation Leaks

Attic beams and insulation.

Have you ever noticed how tightly sealed newly built homes are? A family friend recently purchased a newly constructed home that is sealed so tightly, it takes physical effort to open and close interior doors. An older house, however, is a different case entirely. With time, the ground moves and shifts, as does the house and the joists holding it together. Leaks caused by a messy builder can grow or crack further, and even the most insulated of homes can become airy and filled with drafts. But what can one do about it? How can a homeowner even tell if their home has insulation leaks in the first place? This article will explain how an older home can find energy efficiency by identifying and sealing insulation leaks the DIY way.

The Most Common Places to Find Leaks


Ductwork and ceiling beams in an attic.

Attics in older homes are known for being drafty and uncomfortable places, often only used as a storage space. They're common ground for insulation leaks, but they can easily be fixed if one only knows how to find them. A simple interior inspection of the area can tell all one needs to know. Here are some things to look for.

Follow the Pipes and Wires

If your house is anything like mine, your small attic space is littered with pipes and wires with no apparent destination in mind. These are wonderful to follow in the search for air leaks. It's also wise to examine the areas surrounding chimneys, attic hatches, and windows as well.

Look for Color Changes

If the insulation is present and easily accessible, look for consistency in the color of all the cuttings. A dark or off-color piece of insulation usually warns of a leak in the general vicinity. The color change is simply caused by air sneaking in through a small hole in the wood the piece is held against, and with it comes moisture that can alter color.


A basement window with rain on the pane.

In the lowest parts of a house, there are a lot of pipes entering and leaving the home since water heaters, washing and drying machines, and even sump pumps tend to be located there. Assuming your basement in unfinished and has walls and beams exposed, this is an easy place to access, inspect, and repair holes, fixing energy waste. Here are some insulation leak traits in this type of environment.

Basement Windows

I think many builders, eager to work on the much more exciting upper floors above, rather hurriedly finish home basements. In mine, for instance, the windows are rather sadly constructed and are the main way a large colony of ants enters my house when the weather is warm. In your search for potential insulation problems, the sealant surrounding each window should create a seamless and finished look. When it doesn't, it often proves to be a main way of air entry.

The Beams

Using a flashlight, study the beams, joists, and insulation that act as the underside to the floor above. There should be no holes or cracks allowing airflow surrounding the pipes and air conditioning/heating ducts. As mentioned before, all insulation present should be uniform in color.


Especially in older homes, original cement or stone foundations tend to have holes and cracks that let in air, water, bugs, and small creatures. These gaps are often plain to see, yet easily overlooked. Using a flashlight, run a hand over all surfaces, paying special attention to areas that have access to the outside world (around water and heating pipes, windows, and basement doors).

What to Do? Try This Simple Solution


So what does one do when they find a crack or hole that lessens the effectiveness of an insulated area? Some experts suggest DIYers follow remedies that require many tools and materials—and those solutions can admittedly be effective. While attics and basements differ greatly (mainly because basements often have high levels of moisture), a single solution can work well for both.

For an attic, small to medium sized holes can be easily filled with a universal agent that I have used in many parts of my house: caulk. This material is actually made to be a sealant surrounding tubs, sinks, and showers, but as a water resistant, permanent material, it has many applications. When sealing an air leak, tube caulk is an easy and cost-effective solution.

For larger holes, such as gaps located around ductwork or exposed piping, some patching may also be required. The remedy is just as simplistic, yet involves the added step of cutting a piece of drywall or foam board to fit the hole and adhering it with nails or screws. Make the area airtight by using caulk around the board’s edges.

In a basement, caulk can be used to seal space around water and heating pipes, as it can withstand high, troublesome temperatures. It also works around drafty windows and in cracks from shifting foundations. Just apply and allow 24 hours for the product to fully cure.