Dryer vents through roofs

Often, when I see a dryer vent vertically out the roof, the vent termination cap has a wide grill and a cap over it. Often, they are clogged or partially clogged.

The 2006 IRC states: “Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.”

If you are familiar with what I’m talking about, those vents through roofs, do you think they meet the definition above? (To me a damper is a flap device and I don’t think they have them.)

Photo: Dryer vent is right side of plumbing vent.

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Did it look similar to this?


It happens frequently, when the vent does not get cleaned. I would imagine that this could be a hazard due to gasses or fire.



I use this in the appendix of my report:

The exhaust duct for the dryer should be metal. Be sure to clean the lint from the duct on a regular basis as it can restrict exhaust air flow leading to overheating in the dryer. Recent statistics from one year in the United States are instructive as to how important the two previous items can be:

DRYERS- Fires caused by: 14,600 ________Deaths: 20 __________Damage: $87 millions

That vent looks like it was made as a bathroom roof vent and has a mis-applied use!!



Some info .
… Cookie

From this site:

Dryer vent pipes vented out through the roof must be vented through a special “dryer roof vent”. (make certain that the screen has been removed) Dryers cannot be vented through the regular square type roof vent. These vents due to their design, get clogged with lint and are considered a fire hazard.

If it was a “special” dryer roof vent, why would it have a screen to remove in the first place or is the unit a converted sidewall kit?

If it’s got a screen and lint is moving through the dryer vent, the screen is likely to get clogged whether it’s on the roof or wall. Seems like accessiblity for cleaning purposes is the issue.

Dryer vents should not go vertical at all. Dryer blower motors aren’t designed to force exhaust upward and will have a shortened life. Most manufacturers, that I have seen, are pretty clear about this.

Can you give me an example of a manufacturer with this requirement?


I can not find any information regarding this .
Some of the corcerns with roof venting is to make sure you insu;ate it in the attic if you live in a cold area .
Through the roof could be harder to clean the pipes
( We all of course clean our pipe yearly Correct ) you need a proper spring vent no screen on it .
Remember support the vent pipe in the attic.

Ther vast majority of dryers in our area are located in full 8’ deep basements. to get to the rim joist they all have to blow air up at least 7-8 feet to vent to the outdoors.

My own dryer (almond colour) has been blowing up the 7’-8’ for 23 of its 33 years!! And it doesn’t seem to want to break badly enough that I can’t repair it!! The joke with my wife is that when I die she can buy a new dryer with the insurance $$$; until then we’re using what works. (so Scottish!!)