Acceptable Dryer Venting Through Slab Foundations

Full Outdoor Venting

• When you vent your dryer, vent all the way to the outdoors. Do not vent partially through your basement, or into a garage, or any other structure. The vent needs to go all the way through the foundation and into outside air. Trying to vent into an area such as your crawl space will only create moisture problems and mildew issues that you will have to address later.

Foundation Vents and Sealing

• The chief problem with venting through a foundation is sealing. You will need to enclose the vent with an air-tight seal that keeps any air from entering or exiting around the vent duct work. In a slab foundation that is already made, this may be impossible. However, you might be able to install an alternative device such as an automatic foundation vent that creates an opening for your duct work to move through while also sealing itself against the concrete.

Insulation

• Insulation is another key element when you are venting through a slab foundation. Foundations can become very cold in winter months, which leads to greater condensation within the duct work and the potential for leaks. Insulation will keep the duct work your dryer uses from becoming too cold and developing these issues.

Leveling and Length Issues

• If you have your dryer at ground level, you might want to avoid venting down into a slab foundation. Dryer vents should be level or at a slow decline whenever possible. Venting steeply down into a foundation is asking for pooling condensation and leak issues. Likewise, don't vent more than 25 feet away from your dryer itself, no matter where you put the vent.