I had a roof leak inside my garage, so I cut a hole in the ceiling sheetrock and traced it and found the spot that is wet and most rotted, took some measurements and went up to the roof and marked that spot with white tape. It is the "+" next to the vent. Then I called a roofer(I don't DIY roof repairs because I get rubber legs if I get on the roof).



I thought it was a circulation vent for the attic space...the roofer came and said it is leaking around the vent and so he removed the vent, tiles and membrane in that area and found two spots where the membrane was penetrated.

However, the removed vent and the membrane has a lot of lint in it. He said it must have been a dryer vent once upon a time. The current dryer runs into the crawlspace and out a side wall so that vent is not connected to anything.





So my first question is - is it normal/typical at all to exhaust a dryer out the roof? I have never seen this myself.

Then the decision I need to make was, do I want to put that vent back with a hole to the attic, or just close it up and remove the vent? I had a decide at that moment...and since I know I will need a vent (for the washing machine) because the washing machine is unvented at the moment, I asked him to drill a 3" hole and put the vent over it. Now I think it's a bad decision because it is not likely the washing machine vent pipe will end up being in the same exact spot. But it's done now.

If the house is slab on grade and dryer is centrally located, it might be an issue trying to sidewall vent it. I don't see many residences with roof dryer vents, but laundromats roof vent all the time. There was plywood there for roof sheathing, where the rot was, and 1x boards surrounding the plywood, so it seems to me that maybe the plywood was installed because of previously rooted sheathing? I think you made the right decision for keeping the vent. Run the laundry pipe to it. Otherwise, you'd be calling the roofer back to open up another section of the roof.

steve, you are right. The original roof is 1X6 tongue and groove planks back in 1941. In 1992 they tore down and rebuilt the garage due to a fire. I believe they switched to 3/4" plywood then. It has been leaking for some time.

I have never seen residential dryer vent out the roof. Seems strange, someone would have to climb on the roof to clean the lint off the vent opening?

We had a new house built in NE OK in 2012. The dryer vented through the roof. Every house in the subdivision was built that way.

It is not a good idea to vent a dryer thru the roof as lint can build up and the dryer won't have enough force to lift it the height of the roof. It can sometimes cause a fire.

(shown prior to insulation)


as with everything else there are corect ways and incorrect ways

[www.finehomebuilding.com]


'device' should be interlocked with dryer preventing (dryer) operation if ductwork is obstructed

Quote

The typical maximum-allowable duct run for dryers is 25 ft.; anything longer than that requires a booster fan. The 25-ft. limit presumes a 4-in.-dia. smooth, straight run, so flexible duct and fittings reduce the limit. A 90° elbow has the same airflow restriction as 5 ft. of straight pipe, and a 45° elbow will cost you 2-1/2 ft. of duct run.

Also, insulate the duct in unconditioned space. If it stays warm, it will be less likely to form condensation and collect lint.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 2 times.

Around here (No Calif) many homes have drier vents terminating out of roofs.