Could not locate dryer vent termination

M Kelekci · 09-22-2007, 05:30 PM

Dryer is in the utility room. Could not locate where it is terminating.
Questions
1. How many feet run can the dryer vent duct be?
2. Can it be vented thru roof?

Thanks,

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**John Arnold** · 09-22-2007, 05:51 PM

Yes, it can be vented through roof.
I found one once terminating in the attic in a trash can with screening over the top.

**Scott Patterson** · 09-22-2007, 06:00 PM

Originally Posted by M Kelekci

Dryer is in the utility room. Could not locate where it is terminating.
Questions
1. How many feet run can the dryer vent duct be?
2. Can it be vented thru roof?

Thanks,

I want say that 25' is the max length for the dryer vent pipe without it needing a booster fan. I bet that if you go to a dryer manufacturers website you can look it up.

**Michael Thomas** · 09-22-2007, 06:13 PM

Per M1502.6 <= 25 feet dryer location to the wall or roof termination. Less 2.5 feet for each 45 and 5 feet for each 90-degree (not inc transition duct) or per manufacturer’s installation instructions.

Nolan Kienitz · 09-22-2007, 06:50 PM

Matt,

Which Houston community was your inspection? One or two story home? Odds are it took a dive into the wall and up through ceiling/attic and out the roof. At least one 90-degree turn and possibly two.

As noted earlier ... Max run on a dryer vent pipe is 25'. Each 90-degree turn costs 5-feet and each 45-degree turn costs 2.5-feet in distance calculations.

Now ... a booster fan can be installed, but if they are they should be accessible for service/maintenance, etc.

I've seen many in custom homes that were "not" service accessible ... I was fortunate to be doing the framing inspections and "caught 'em". Otherwise you may not readily see or run across unless you start digging and calculating "assumed" routes of the pipe.

**Jerry Peck** · 09-22-2007, 07:08 PM

Some dryers will push (are rated at) 90 feet, no booster fan required.

Thus, the answer is "It depends.".

M Kelekci · 09-22-2007, 07:09 PM

Originally Posted by Nolan Kienitz

Matt,

Which Houston community was your inspection? One or two story home? .

Houston Suburb Fairfield area. Two story.

Originally Posted by Nolan Kienitz

Odds are it took a dive into the wall and up through ceiling/attic and out the roof. At least one 90-degree turn and possibly two.

As noted earlier ... Max run on a dryer vent pipe is 25'. Each 90-degree turn costs 5-feet and each 45-degree turn costs 2.5-feet in distance calculations.

Now ... a booster fan can be installed, but if they are they should be accessible for service/maintenance, etc.

I've seen many in custom homes that were "not" service accessible ... I was fortunate to be doing the framing inspections and "caught 'em". Otherwise you may not readily see or run across unless you start digging and calculating "assumed" routes of the pipe.

This house was built by Lennar. I don't think builder took too many shortcuts, however I still don't trust the subcontractors. They might have just put the vent duct in the wall chase or just routed it to the attic somewhere under blown in insulation, because I did see a plumbing vent terminating in the atttic.

What are the signs of having a dryer vent thru roof? Wasn't I supposed to see the lints over the roof? Any particular roof jack type?

This is a 2 story house. Let's assume it is 9 feet per floor. 2x9=18' plus the attic. I am sure there is at least 1 90 degree. Looking at this numbers, I don't think it is in compliance with the code.

Is it still 25' for vertical runs?

Thanks for the prompt responses.

**Bruce Breedlove** · 09-22-2007, 08:14 PM

Originally Posted by M Kelekci

What are the signs of having a dryer vent thru roof? Wasn't I supposed to see the lints over the roof? Any particular roof jack type?

You will see a dryer vent at the roof. Usually there will be lint around the opening and below the hood, often times preventing the flapper from closing (if the vent has a flapper).

**Jerry Peck** · 09-23-2007, 06:39 AM

Originally Posted by Bruce Breedlove

(if the vent has a flapper).

It's *supposed to have* a damper.

It's *not allowed to have* a screen.

**Scott Patterson** · 09-23-2007, 07:48 AM

Originally Posted by M Kelekci

Houston Suburb Fairfield area. Two story.

This house was built by Lennar. I don't think builder took too many shortcuts, however I still don't trust the subcontractors. They might have just put the vent duct in the wall chase or just routed it to the attic somewhere under blown in insulation, because I did see a plumbing vent terminating in the atttic.

If you can't see it, you can't see it and you need to report it as such. If a dryer is in the home, I have turned them on when I have had trouble locating the vent. This works great as you can hear and sometimes see it.

What are the signs of having a dryer vent thru roof? Wasn't I supposed to see the lints over the roof? Any particular roof jack type?

You will see the vent housing. Most of the time it looks like a box with a slanted side. Several designs but you will see it. Now if they ended it at a soffit vent in the attic you might not see it. Also I have seen soffit mounted dryer vents that discharge to the exterior.

This is a 2 story house. Let's assume it is 9 feet per floor. 2x9=18' plus the attic. I am sure there is at least 1 90 degree. Looking at this numbers, I don't think it is in compliance with the code.

Is it still 25' for vertical runs?

Thanks for the prompt responses.

Hard to say, but chances are that it is not. ?With two floors and one 90 degree turn you are just shy of the max distance. You are the only one that can really tell as you were at the house.