I have added a small second story addition on my house that enclosed a
roof vent for my kichen sink. The contractor plans on installing what
he called a "cheat vent" because it vents into the attic. He will of
course have to extend it up a few feet to get into the new attic space.
It does not require him to punch a hole up through the roof. He said
it has a spring like flipper on the top that only opens when air is
being sucked. His reasoning for this is that he wants to minimize the
number of cuts into my roof because of its low pitch. It is almost a
12:4. I already have my chimney, two roof vents and a bathroom vent
poking through and have never had an issue.
My question is, do these things work adquetely, this is a kitchen sink
and I do not want it to be a slow drainer? Will it add moisture to my
attic? I have a very dry attic and have worked hard to vent exhaust
fans and other items outside of the attic. Any reason why I should not
let him use this type of "cheat" vent?
Thanks for all your help.
I wouldn't allow it. a 4/12 is not a low pitch, and punching a vent
through it is not a big deal. Are you subject to plumbing inspections?
I can't imagine a plumbing inspector would let that pass. my
understanding is these devices are used as a last resort, when
conventional venting is not possible. your situation isn't even close
to a last resort.
It's a mechanical vent. Some places allow them, some don't.
In any event, I wouldn't put one in an attic. That's poor design.
If you get freezing temps where you are, it probably will freeze
Instead of cutting another roof termination, he should TEE into
an existing vent.
Back to your question: No they won't add moisture to your attic;
they only draw air in.
Some jurisdictions allow side venting, others don't. Concerns include
where vapors go that come up from the sewer -- some idiot pours gas down
a drain, the fumes come up your vent stack, do they dissipate outdoors
or accumulate in your attic?
firstname.lastname@example.org is Joshua Putnam
I have a vent that goes out the side of the house, and then straight up 6
feet, completely unsupported. I took the 6 foot extension off, since it was
only a matter of time until it broke off. Now, occassionally, it doesn't
smell too good in that area.
Would putting a spring loaded damper on it help, or would it just ruin my
It would ruin your venting. The vent works two ways. It relieves the
vacuum when the last of the water goes down the stack so you don't
suck the traps dry and it also gives backed up sewer gas a way to get
up and out. It is methane rich, even without that gasoline mentioned
You can use a Studer Vent like the OP has for the vacuum break but you
still need at least one free vent to air and that should be above the
roof line. There are rules about the height, roof pitch etc.
The air admittance vent (Studer is a brand) must remain accessible.
Confused, is this a real plumber, who is governed by codes and an
overbearing inspector? ;)
I would suggest you get help from your local code enforcement
personnel. Many times trades people will take shortcuts to not
'cross-trade', meaning this plumber does not want to do roofing work.
tom @ www.Consolidated-Loans.info
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