Q&A / 

Dryer Vent Ice Dam

Mark has an ice buildup and ice leaking out of his soffit where his dryer vent exits his home. It's pretty severe. Here's his story:

"I am getting icicles on the side of my house near the dryer vent. This happens in Nebraska sub-zero weather. This side of my house faces the northwest.

I made sure the duct extends all the way to the exit. The vent flaps on the hood outside properly open slightly when the dryer is on.

There is no obstruction that I could see in the duct when I shined a flashlight in the duct.

Do I have a problem with my siding and/or dryer vent that should be corrected?

I am concerned this could, in the long term, rot the under-layer siding and/or get moldy underneath.

Or it could just be the condensation that I have to deal with in these conditions? Here's a photo of the ice."

This amount of ice indicates vast amounts of water vapor are seeping behind the siding where it WILL CAUSE rot and mold. Photo credit: Mark Nielson

This amount of ice indicates vast amounts of water vapor are seeping behind the siding where it WILL CAUSE rot and mold. Photo credit: Mark

Mark, I know exactly what's going on.

First and foremost this is a serious problem. You're correct that it's condensation from the hot water vapor from the dryer. You're going to deal with this in the spring or at an earlier warmup.

If you don't you will have rot and mold for sure.

If you have access right on the other side of that wall in the basement where the pipe is, it's going to be easy.

You just need to disconnect the pipe from in the basement and pull it OUT to the outside.

It's best if you can pipe from the basement to the outside wall louvered wall cap as ONE SOLID PIPE with no joints. Also, you MUST get access to the soffit once the pipe is reinstalled.

It’s imperative that you insulate completely around the pipe. It's got to be WARM so condensation is at a minimum while the dryer operates.

You will get some condensation in the pipe no matter how well you insulate it. The longitudinal seam in the pipe must face the SKY so any condensate heads back to the basement.

Slope the pipe back to the basement if possible so condensate collects in the basement, not in the pipe in the wall.


One Response to Dryer Vent Ice Dam

  1. I would run the clothing through another spin cycle and extract as much water as possible before they go into the dryer. The less moisture going into the dryer the less coming out!.
    What type of dryer does he have? If electric, he should make sure that all elements are working. I had A dryer I bought used and it had A long run time to get the clothing dry. Upon inspection and troubleshooting I found A burned out heating element and after replacement it worked like new. As I didn't care to replace this element again I now double spin my clothing before they go into the dryer and I save A bit of money as it cost less to run the spin cycle than run the dryer.
    Good Luck!

Leave a Reply

You have to agree to the comment policy.