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Dryer vent clogged

I couldn't find any related topics, so...

In my 3 month old new constructionhome I have a clogged dryer vent. The run of the dryer vent (galvanized pipe, 4" dia.) has a 90 going up to the ceiling, 40-45 to the roof and then a 40-45 to the roof vent. The roof vent (see pic) is where the clog is. Total length is about 15 ft. The clog occured at the roof vent. It built up ont the screen to prevent birds from entering (which is a HUGE problem in our sub division). It makes a perfect rectangular patch of lint. I don't want to remove the screen otherwise I"ll have birds in the vent. The screen is small, maybe 1/4" square mesh.

I don't want to have to climb up on the roof every two months to remove the build up. Any suggestions? Thanks in advance,


Re: Dryer vent clogged

I would suggest a vent with a magnetic flapper that opens when dryer air pushes and closes with magnetic grab when dryer is off but the birds may enter while it is open.

How about an in line "filter" to catch the lint that is getting past the dryer lint screen. Maybe some pantyhose stretched across a section of your 4" pipe that you can easily access and clean every other load.

How about a larger screen cage around the vent and then you can remove the screen that is getting clogged.

Re: Dryer vent clogged

I will have to look into the magnetic thing. As for the panty hose thing, that would be too much a pain in the a$$ to do every load, why not just rod it out every load.

As for the larger screen I was told that anything larger than 1/4" mesh would be large enough for a bird to get through/into to cause a problem.

Supposedly the HVAC company is going to come back and install a larger vent cover similar to what is on our fireplace chimney, a 360 degree open vent, that should eliminate the clogging.

Re: Dryer vent clogged

I have the same issue. Our house was built late 2006 and it seems every few months we have to climb up there and clean the vent out. I found an in-line lint filter from Lambro Industries
(4" x 5' LamaFlex Duct Lint Trap Kit) that appears to go between the dryer and wall hook-up. It is only $13 (Lowes Home Improvement). Seems like it is a cheap way to address this, but like you mentioned may be a pain (although less of a pain than climbing on a roof). I am going to try it and see how it works.

Re: Dryer vent clogged

Did you take the elbows into your length calculation? By NFPA, dryer exhaust must be increased when the run exceeds 25 feet. Each 90 degree elbow counts as 5 feet in itself, so 15 feet of straight pipe and 2 elbows equals the maximum length without increasing. Use 26 ga metal pipe, as flex line increases resistance. 5 inch vent hoods can be difficult to find if you need to increase it. If you can somehow vent it at a closer location or move the dryer closer to the termination point, it will be better. I would vent out a wall if at all possible. DO NOT USE SCREWS to connect pipes or elbows, as they will catch lint. Besides the fire hazzard of a clogged dryer vent, if you have a gas dryer, it can also dump dangerous carbon monoxide into your home when clogged, since the vent pipe also expells combustion gases.

Re: Dryer vent clogged

The trouble with the 4" x 5' LamaFlex Duct Lint Trap Kit is that it is to be used instead of a rigid duct system. It vents back into the laundry room. It is a dead end vent. I think I might try the Dryer Booster Lint Trap - Fantech Model DBLT4 from R. E. Williams Contractor Inc. I will have to install it between the dryer and the roof vent. I will mean cutting a hole in the laundry room wall to install it but will allow me to filter out more of the lint before it reaches the roof vent. Putting a cover or a door over the hole will make it more pleasing to look at and allow me quick access to it. This company also sells in-line fans to boost the air flow.

Re: Dryer vent clogged

I personally would never run a dryer vent up through the roof.

Re: Dryer vent clogged

is it possible for you to vent a pipe out your wall between your floor trusses. i would try the spring loaded,sealed flap dryer vent. i had the same problem with mine.

Re: Dryer vent clogged

I did not have a choice were the dryer vent was routed. That was were the builder had it designed. Might have been a code issue. The dryer is on the second floor of a two story house so the most direct route was through the roof. Any other route would have involved one or more 90% turns, My last house, a one story model, had the dryer vent through the roof also. On that one I was able to get access to it from the attic and clean it from there. The vent tubing on this house is surronded by air conditioning ducts so it can not be reached from the attic. I am hoping that putting an extra filter in the vent line I will remove most of the problem lint and reduce the need for cleaning the vent hood on the roof.

Re: Dryer vent clogged

Locate and purchase the DBLT4 lint trap from FanTech which is a secondary trap in the exhaust duct and catches the lint that would normally go out the duct.


Every dryer exhaust duct should be usinfg them in my opinion.

Re: Dryer vent clogged
paretoslaw wrote:

Are you usinfg one?

When I start doing my own laundry again ---- yep ---- I'll be usinfg one. :D


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