How To Seal Around Pipes & Vents

Once you have identified air leaks around pipes and vents, both interior and exterior using our "how to find air leaks" guide, use these directions to seal them up.

There are two foam sealants you can use to seal these gaps:

Latex foam sealant:

Easy to apply and clean up, latex foam can be used to seal up small air leaks and gaps.

Before starting any project, be sure to read the entire package to ensure you have all materials the job will require and to budget for dry times in your project. Carefully review all safety precautions on the package. Latex foam sealants are EXTREMELY FLAMMABLE WHEN DISPENSING! Refer to the Material Safety Data Sheet and product label for additional information. Extinguish all ignition sources during use and dry time. Wear safety glasses and gloves and use in well-ventilated areas.
Clean and dry the surface you will be sealing to ensure it is free of all dirt, dust, grease and debris.
Follow manufacturers instructions on product application. Most latex foams dispense at 90% of their final size, so make sure to leave room for the foam to expand an additional 10% of its dispensed size.
Make sure to apply at temperatures directed on can.
Fill the gap between the wall and the pipe by applying foam around the circumference of the pipe. Latex foams can be tooled or shaped while wet.
Application not recommended for use at or below grade or for closed cavities.
With latex foams, undried foam can be cleaned up with soap and water. Excess dried foam can be scraped off.

Polyurethane foam sealant:

As these products are packaged in aerosol containers, it is very important to read the entire package to ensure you have all materials the job will require. Carefully review all safety precautions on the package. Foam sealants are EXTREMELY FLAMMABLE WHEN DISPENSING! Refer to the Material Safety Data Sheet and product label for additional information. Extinguish all ignition sources during use and dry time. Wear safety glasses and gloves and use in well-ventilated areas.
Make sure you have a clean and dry surface that is free of all dirt, dust, grease, and debris. All areas not to be foamed should be covered with masking tape or drop cloths.
Follow the instructions on the package of the product you have selected. Polyurethane foams expand and dry very hard, so be sure to follow directions closely so as not to damage your pipes or surrounding surfaces. Before applying around piping, familiarize yourself with the foam by practicing on newspaper. Gauge expansion by allowing test line of foam (called a "bead") to expand for 60 minutes as most polyurethane foams expand at least two times their dispensed size.
Make sure to apply at temperatures directed on can.
Fill the gap between the wall and the pipe by applying foam around the circumference of the pipe, leaving enough room for the foam to expand. Do not disturb foam while wet.
Application not recommended for use at or below grade or for closed cavities.
Dried foam exposed to sunlight must be coated with paint or stain.
Undried polyurethane foam can be cleaned up with paint thinner or acetone. Excess dried foam can be removed by trimming with a sharp knife. DO NOT use acetone or other solvents to remove product from skin.