Author

Topic:   termination of dryer vent thru roof - 1306 visits (1 today, 5 this week)

Al Roden
Member


Posts: 448
From:Victoria, Texas
Registered: Mar 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 14, 2006 10:14 AM            

Most dryer vents that go to the roof just terminate inside a roof jack - they are not sealed to the roof jack and lint falls back onto the attic insulation.

So how is it supposed to be installed to prevent lint from falling back down - would you seal the joint of the pipe to the roof jack with foil backed tape?

Jerry Peck
Member




Posts: 8270
From:Pembroke Pines, FL
Registered: Feb 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 14, 2006 10:44 AM            

That is because they are NOT using the proper roof jack.

The ones made for dryers have a 4" duct fitting attached to a plate which is made onto the bottom of the roof jack and closes that off. These also have a damper.

When the dryer duct is attached to the duct fitting sticking out for it, everything is 'sealed' together.

------------------
Jerry Peck
South Florida

Al Roden
Member


Posts: 448
From:Victoria, Texas
Registered: Mar 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 17, 2006 12:21 PM            

Thanks Jerry...sadly, I've never seen a dryer vent over a roof with a backdraft damper.

If they come back with foil backed tape, etc. and seal it up where it meets the roof vent...would that be considered adquate or is the only proper repair for this to install a new, appropriate backdraft damper designed for this purpose?

Jerry Peck
Member




Posts: 8270
From:Pembroke Pines, FL
Registered: Feb 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 17, 2006 04:14 PM            

Al,

"If they come back with foil backed tape, etc. and seal it up where it meets the roof vent...would that be considered adquate or is the only proper repair for this to install a new, appropriate backdraft damper designed for this purpose?"

In my opinion, only that latter is "correct".

Frank Bombardiere
Member


Posts: 168
From:Oklahoma City, OK
Registered: Aug 2002

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 18, 2006 05:23 PM            

Now here is a nice dryer vent installation I saw on a new home the other day.Click for photo (65058 Bytes)

Jim Vaughn
Member


Posts: 80
From:Arlington, VA
Registered: Jan 2001

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 20, 2006 12:03 AM            

I haven't seen a roof mount dryer vent that wasn't clogged - with the exception of new construction.

Jerry Peck
Member




Posts: 8270
From:Pembroke Pines, FL
Registered: Feb 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 20, 2006 05:07 AM            

Jim,

Probably because they were an improper type (most common on older homes) and /or had a screen (most common on newer homes).

If the proper type and no screen, they take a long time to clog, and many do not.

But put a screen on them and they will be clogged in less than one year.

------------------
Jerry Peck
South Florida

Brent Koerting
Member


Posts: 105
From:Ramona, CA
Registered: Jan 2001

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 20, 2006 05:26 PM            

Mine has terminated through the roof since I built the house 15 years ago and always works fine, stays cleaner then a vent with a horizontal run.

Wen Myrick
Member


Posts: 631
From:Sacramento Ca.
Registered: May 2004

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 23, 2006 08:11 PM            

Brent Hi,
I have never spoken to you , welcome...

Heres my thought on the subject....being as this is all about input, being in this site.

I have seen lint build up with horizontal venting thats a meer 2-3 feet (firehazard)

I have seen lint on roofs (firehazard) with vertical termination

so when you see the lint trap clean in the dryer (if you check them) but still see lint from the exterior routed venting.....

There is a potential problem....(firehazard)

(maybe theres potential for dryer sweeps LoL/as opposed to chimney sweeps)

I always make sure that there are no turns in the venting (that its direct)

because if there are turns the lint builds up! its loaded daily with moisture....because We dont dry, 'dry' clothes We dry wet ones.... potential for Mold now!

Most dryer venting isnt taped and sealed because the buider doest think its a hazard...

Ive never seen a 40ft dryer vent so i know there has to be joints in there somewhere for roof termination!

Just think logically

its our job!

~Wen~

Mike Schulz
Member


Posts: 379
From:Fuquay Varina, NC
Registered: Jan 2003

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 26, 2006 05:09 AM            

I have inspected several homes that had vertical run dryer stacks that leaked. Most leaked from the moist air condensing and running back down. Most clog over time from lint. See sheetrock damage where it enters through the ceiling from leakage. Dryers don't have super fans so why run it vertical for 20 to 30 feet. Poor design to me.
Mike

Jeff G. Hooper
Member


Posts: 822
From:Palm Beach Gardens, FL
Registered: Jan 2005

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 26, 2006 01:45 PM            

The maximum allowed length is 25'. Reduce 5' for each 90 degree bend and 2.5' for each 45 degree bend. And yes, there are dryers that are approved by their listing for up-wards of 75' of vent. You must read the listing and labeling of the specific dryer.

David Banks
Member


Posts: 420
From:Southborough, MA.
Registered: Mar 2004

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 26, 2006 02:09 PM         

This is what I incude in my reports.

VENTING: Dryer should be vented. Suggest rigid metal vent pipe (Aluminum or galvanized) for dryer as plastic is fire safety issue! Especially if concealed. Maximum length should not exceed 25 feet. Dryer exhaust booster can be used to exceed 25 feet recommendation. This should be placed within 15 ft from dryer outlet. Best on vertical applications. In cold climates insulating the dryer exhaust duct in unheated spaces may limit condensation from forming inside the duct and collecting lint.
Dave

Brent Koerting
Member


Posts: 105
From:Ramona, CA
Registered: Jan 2001

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 27, 2006 05:37 PM            

Hello Wen Thanks

I was doing some home inspection for a bit (couple years) but I'm doing Building Inspection again. So I'm on here time to time just to share thought from the field and give other view points being there is much talk about regulations and AHJ information.

Just my experience: I never have any lint build up but I don't have any other elbows or horizontal runs. I also have a t at the bottom with a cap on the opposite side of the wall where there is a cabinet (I put it in when I built the house) there is never anything in it. No lint aside from a light dusting across the roof time to time.
Also most of the new homes I inspect they are vented through the roof (homes that are running a million plus any more generally don't have laundry in the garage any longer.) They need to by design.

Wen Myrick
Member


Posts: 631
From:Sacramento Ca.
Registered: May 2004

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 28, 2006 12:06 AM            

HI Brent......

I have had to do mold/moisture remdiation from some funky venting on homes for dryer venting foupas (how is that spelled?)

Hey a couple of questions for you;

how long ago did you install that T ?

What do you think might be at that capped end of the T if you opened it?

How often do you do laundry?

Does your dryer have the new double lint traps that you empty after each load?

I have a 2 foot termination on my home directly to the outside and empty the trap after EVERY load....

I still have to vaccuum the back porch vent and wipe down anything close to it....I have a new maytag...and new flex vent... (please beware)

Just wondering and sharing,
~Wen~

John Arnold
Member


Posts: 715
From:Philadelphia PA
Registered: Dec 2001

Sponsors keep
InspectionNews.com FREE.
Have you clicked on a
banner ad today?

If you don't click,
who will?

posted January 28, 2006 03:49 AM            

Wen - faux pas.