How to seal a dryer vent pipe: Sealing gaps of all sizes

Learning how to seal dryer vent pipes is an easy way to prevent moisture issues and pest intrusion. Find out what products and procedures will provide the best results.

• How to seal dryer vent pipes: An important installation tip
• How to seal dryer vent pipes: Closing large gaps
• How to seal dryer vent pipes: Dealing with small- and medium-size gaps

How to seal dryer vent pipes: An important installation tip

It’s vital to seal your dryer vent properly as you are installing it. Once the dryer is pushed back into place, this little detail is easily forgotten. But leaving gaps around the pipe may result in heat loss and moisture problems. It might also leave a pathway for insects or other pests to enter your home. Here are a few things to consider when installing or servicing your dryer.

It’s best to position the dryer so that the dryer outlet is as close as possible to the vent opening in the wall. Short straight runs minimize the buildup of lint.

Another consideration is the type of vent pipe you choose. Rigid or semi-rigid duct pipe is now the preferred type among professionals. The old foil ducts tend to collect lint and are prone to slippage and tearing.

After installing the dryer duct, seal the gap all the way around the exterior of the duct where it meets the wall.

How to seal dryer vent pipes: Closing large gaps

If you have a gap larger than 13mm (½”), it is too big for most acrylic and silicone sealants to effectively protect. We recommend an expanding foam. Here are some tips for getting the best results.

1. Clean the area of dust, dirt, and lint before applying the foam.
2.  Shake the can of foam vigorously for 30 seconds to 1 minute.
3. Insert the extension tube into the nozzle and turn the can upside down to dispense.
4. Squeeze the trigger and inject foam into the gap.
5. Spray a little at a time and allow it to expand. Add more until the area around the vent pipe is completely sealed.
6. Clean any tools or spilled foam immediately. Use acetone on a clean cloth. Wear nitrile gloves for this step.
7. Once the foam has cured, cut away the excess so that the foam is flush with the wall surface.
8. Apply paint, sealant, or mortar to the foam. This is especially important on the exterior side to protect the foam from UV light.
9. Install a vent hood or cover over the outside of the opening.

Looking for a more rigid solution? In cases where you need a more solid material to seal a dryer vent pipe, Loctite Epoxy Gel is a great option. Just dispense equal amounts of the two components, mix, and apply. This gel formula won’t drip or run and forms a durable, rigid bond in just 6 minutes.

How to seal dryer vent pipes: Dealing with small- and medium-size gaps

Smaller gaps can be filled with a good-quality sealant. You can choose a paintable acrylic latex sealant, 100% silicone sealant, or a silicone-fortified latex that is paintable. Silicone is excellent for the exterior side of the vent as it is the most water resistant and flexible. However, pure silicone is not paintable.

As you inspect your dryer vent from time to time, you may find that a small gap or tear has appeared. No need to get out the caulking gun and open a new cartridge of sealant. Here’s a quick and easy way to make those repairs.

Loctite Extreme Glue is a super versatile adhesive that is perfect for sealing dryer vent pipe leaks. The high-viscosity and permanent flexibility make it resistant to vibration, moisture, heat, and UV light. Extreme Glue dries clear and can be used indoors and outdoors, and it even stands up to extreme temperatures!