Multiple vents through one opening - InspectionNews

Jeff Eastman · #1 (**permalink**) 06-02-2007, 01:14 PM

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Jon Randolph · #2 (**permalink**) 06-02-2007, 05:30 PM

I may be wrong, but it appears to me that the vent pipes are "stuffed" into the opening for a roof vent. All household vent fans should be vented to the exterior of the home. Stuffing them inside a roof vent is not the same as venting to the exterior.

I don't know the code that applies, but I'm sure that someone will post it.

Thom Walker · #3 (**permalink**) 06-02-2007, 06:57 PM

That's some creative use of truss plates. What part of what kind of roof am I looking at?

And were those vents going out of a roof vent?

Jon Randolph · #4 (**permalink**) 06-02-2007, 07:24 PM

[quote=Thom Walker;7909]That's some creative use of truss plates. What part of what kind of roof am I looking at?

QUOTE]

Kind of hard to tell, but that looks like it may be a manufactured home.

Bob Harper · #5 (**permalink**) 06-03-2007, 08:38 AM

These creatures are spreading everywhere!

It must vent to the "outside". Are these secured in such a fashion they are right in that ridge vent and will stay there? Is there any chance someone would need to walk by there that they could disturb those Slinkies? I would at least recommend rigid duct, which could be properly supported and secured so it stays in place. This is a poor practice, if allowed because there is nothing to stop the humidty from recirculating back into the attic to rot the roof deck right there.

Scott Patterson · #6 (**permalink**) 06-03-2007, 08:53 AM

You need to check with the AHJ for the area. They might not require them to go through the roof. Some allow them to terminate in the attic; Some allow them to terminate at a soffit vent; Some allow them to terminate in a vent like the one in your picture. In my area they must terminate outside of the building envelope (out the roof or wall). But, one town down the road allows them to terminate at a vent.

IRC says that they must terminate to the exterior of the home.

Thom Walker · #7 (**permalink**) 06-03-2007, 10:13 AM

Quote:

Originally Posted by Jeff Eastman

This is a house! Not a manufacture home. Truss rafters.

You are looking at a ridge , where the air ducts are routed out.

What's wrong with the truss plates?

A truss plate is "a" type of fastener. It is not "the only" type fastener. From your picture, I see one instance where it may be properly used. That's at the top cord and a compression web. In all other cases I see, they are improperly used where another type bracket should have been used or they are improperly installed. They are supposed to be properly sized for the application. A batch of these aren't.

I realize this is a little picture of a bif space, but at first glance I'm not overly impressed with the framing. But, as my father used to say to me, "If you are so damned smart, how come you're not rich?" Do you have more pictures of the framing and or where the vents come through the roof?

I'm not a huge FEMA fan, but I thought the attached was a handy reference for when I'm on site. http://www.flash.org/resources/files/HGCC_Fact17.pdf

Jerry Peck · #8 (**permalink**) 06-03-2007, 02:41 PM

Quote:

Originally Posted by Scott Patterson

You need to check with the AHJ for the area. They might not require them to go through the roof. Some allow them to terminate in the attic; Some allow them to terminate at a soffit vent; Some allow them to terminate in a vent like the one in your picture. In my area they must terminate outside of the building envelope (out the roof or wall). But, one town down the road allows them to terminate at a vent.

IRC says that they must terminate to the exterior of the home.

The two underlined ones are not allowed by code, and, while the AHJ has the right to "interpret" the code, they do not have the right to "change" the code.

Look at the manufacturer's installation instructions - if those show three going into one, seal around all three to keep the air outside, otherwise, do it like is shown in the installation instructions (I've never seen where three into one have been shown in the installation instructions).

Jon Randolph · #9 (**permalink**) 06-03-2007, 03:04 PM

[quote=Jeff Eastman;7945]This is a house! Not a manufacture home. Truss rafters.

I realize that this is a truss system and that this is the ridge. It looks to me like the ridge is 2 separate pieces fastened together. I see verticle webbing side by side, one on each haf of the ridge.under each half of the ridge. From the pic, it appears that the roof was in 2 separate pieces and tied together (such as when they place a mfgd. home on the foundation and bring the sides together.

Scott Patterson · #10 (**permalink**) 06-03-2007, 06:06 PM

Quote:

Originally Posted by Jerry Peck

The two underlined ones are not allowed by code, and, while the AHJ has the right to "interpret" the code, they do not have the right to "change" the code.

Look at the manufacturer's installation instructions - if those show three going into one, seal around all three to keep the air outside, otherwise, do it like is shown in the installation instructions (I've never seen where three into one have been shown in the installation instructions).

While that is true, I think it all boils down to interpretation and the fact that the AHJ is the voice of authority even if they are wrong.

Jerry Peck · #11 (**permalink**) 06-03-2007, 06:18 PM

Quote:

Originally Posted by Scott Patterson

While that is true, I think it all boils down to interpretation and the fact that the AHJ is the voice of authority even if they are wrong.

True, they are the "voice of authority", and, when wrong, they need to be prompted, prodded, cajoled, poked at, reminded, etc., as necessary to make them realize that they are wrong.

Only then will things change.

Sometimes, many times, it is up to us (HIs) to do that prompting, prodding, cajoling, poking, reminding, etc., and do it in a way which gets the HI and the AHJ to know each other and so the AHJ does not resent, despise, or other pooh-pooh what the HI says, only then will an exchange of information be possible.

Jerry Peck · #12 (**permalink**) 06-06-2007, 07:40 PM

Quote:

Originally Posted by John Stephenson

Ridged vents for bath exhaust air ducts ARE NOT required, correct?

There is no such thing as 'ridge vents for bath exhaust', at least not that I am aware.

Bath exhaust *are required* to discharge to the outdoors.

Other than than, I do not know what you are referring to.

Jerry Peck · #13 (**permalink**) 06-06-2007, 07:45 PM

Bathroom exhaust ducts may be of any approved material, typically you will find flexible metal used.

Clothes Dryer ducts, on the other hand, are required to be rigid metal, with their thickness specified.