dryer vents through the roof

[Bruce A. King]

I heard today that this is becoming a common problem:

Dryer vents clogging up quickly due to condensation inside the uninsulated duct. The clog is occurring up near the roof termination point.

I guess this could occur on ones that run horizontal to a wall too.

I'm going to start recommending these ducts be insulated starting with a predrywall I did today.

Also,
I have started seeing more insulated condensate drain pipes in attics too (new homes). With the larger homes and owners that run the A/C a lot, there can be a lot of dripping condensation off these pipes into the attic insulation/sheetrock.

[Ian A. Niquette]

How long is the run that these are clogging up on Bruce?

[Joe Funderburk, CMI]

Insulating a dryer vent seems extreme to me. What do you have to base that recommendation on? (You're going to make your Realtor friends mad!)

I just say this: "The dryer vents vertically. The lint trap must be kept clean, because trapped lint can rapidly turn into a fire hazard. Inspection of the vent every 6 to 12 months is recommended to ensure it is not clogged."

[Keith Runquist]

Pretty common in dry south west locations and W. Texas but it doesn't get very cold and the dew point tends to be very low. I would guess that a big part of the problem is that no one ever cleans the lint out of the exit point since it's up on the roof.

[Gary L. Farnsworth, CMI]

I see some here in KC. I always have a concern about snow covering the vent.

[Bruce A. King]

Originally Posted by jfunderburk

Insulating a dryer vent seems extreme to me. What do you have to base that recommendation on? (You're going to make your Realtor friends mad!)

I just say this: "The dryer vents vertically. The lint trap must be kept clean, because trapped lint can rapidly turn into a fire hazard. Inspection of the vent every 6 to 12 months is recommended to ensure it is not clogged."

Realtor friends? ha! You know better than that!

A maintenance guy for a homebuilder told a friend about this, he said its becoming a major issue for them. Not sure if he is working for the builder or working on the side but that does not matter.

The typical roof run is probably 20-30 feet depending on the pitch, ceiling height etc. I agree with keith, the problem could be less if these outlets got cleaned once in a while, its just bad design to assume homeowners will do any maintenance.

Nothing wrong with recommending upgrades as long as they are stated as such.

[Nick Gromicko]

http://www.nachi.org/dryer-vent-safety.htm

[Robert Sole]

Thanks for the post Nick. I am always looking for good safety and informational links for my website.

[John M. Murray]

Originally Posted by gromicko

http://www.nachi.org/dryer-vent-safety.htm

Good info that cuts through the reality correct propaganda.






Cincinnati Ohio Home Inspection Services

[Ryan Selwood]

I just recently came across a dryer vent that entered the crawl space before exiting through the wall. The ribbed flex vinyl was completely torn apart and judging by the pounds of lint strown all over the crawlspace, it has been for quite some time. It gets worse too. Although the residence was currently empty(including the dryer), and there were gas and hydro hook-ups available, I could tell by the teflon paste apparent on the gas fitting that it was likely gas exhaust pumping straight into the three bedrooms immediately over that portion of the crawlspace. Those flexible ribbed vents should always be listed a defect.

[Brian E. Kelly]

[Dale Duffy]

Originally Posted by bkelly2

Beat ya--

[Dale Duffy]

Or through a Garage Cabinet terminated in a Cabinet.

[David P. Valley]

I had one yesterday that was venting over a lower roof. The shingles (below) were full of lint.

[Richard W. Washington]

Originally Posted by gromicko

http://www.nachi.org/dryer-vent-safety.htm

Good article.

A dryer vent booster fan should be installed if the run exceeds 25'. This is determined after taking into acct. the 90 degree turn reduces it by 5' and the 45 degree turns reduce it by 2.5'.