Hi there,

Any experiences with air admittance valves?

I'm refurbishing my bathroom.
At the moment the stack pipe takes air from the outside (the roof), and this means that I have a column in a corner of my bathroom.
To save space, and why not to improve insulation, I would like to cut my stack pipe halfway (say at basin overflow level) and close it with an air admittance valve on top.
What do you think?

Also, what's the position of building control about this? Is this stuff regulated?
I'll ask them tomorrow, but BC in my council tends to answer very randomly. So I guess if I get an answer I don't like I'll try again

Cheers,
Julian

"pizza" wrote in message
news

Hi there,

Any experiences with air admittance valves?

I'm refurbishing my bathroom.
At the moment the stack pipe takes air from the outside (the roof), and
this means that I have a column in a corner of my bathroom.
To save space, and why not to improve insulation, I would like to cut
my stack pipe halfway (say at basin overflow level) and close it with
an air admittance valve on top.
What do you think?

Also, what's the position of building control about this? Is this stuff
regulated?
I'll ask them tomorrow, but BC in my council tends to answer very
randomly. So I guess if I get an answer I don't like I'll try again

Cheers,
Julian

pizza


The main stack is there to keep sewer gases from building up inside the
pipes. Sewer gases are very, very explosive and should always be vented to
the open air where possible. Closing the stack with an AAV is a very
dangerous thing to do, but if your BCO guy still gives you an answer you
don't like, then by all means try your idea and find out.


---
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Checked by AVG anti-virus system (http://www.grisoft.com).
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Whoa there Big Wallop,
The vented stacks on your house are there to draw air into the system when
you put water down the pipes. It is not there to let gasses out. If air was
not admitted then as a column of water dropped down the pipe it would cause
a vacuum to be formed behind it and it could and almost certainly would suck
dry all of your water traps on that system. Not a good idea in having no
water trap in your toilet, waste to bath etc.

"Mike Taylor" wrote in
message ...
Whoa there Big Wallop,
The vented stacks on your house are there to draw air into the system when
you put water down the pipes. It is not there to let gasses out. If air
was
not admitted then as a column of water dropped down the pipe it would
cause
a vacuum to be formed behind it and it could and almost certainly would
suck
dry all of your water traps on that system. Not a good idea in having no
water trap in your toilet, waste to bath etc.


So where do sewer gases vent ? If at all ?

I've got a similar and even more inconvenient arrangement to the OP and
would love to get rid of the stack to the roof if possible.

When I wor a lad there were iron "chimneys" in the street, about the same
height as telegraph poles, I was told they were sewer vents. Havn't seen one
for ages though....

"pizza" wrote in message
news

Hi there,

Any experiences with air admittance valves?

I'm refurbishing my bathroom.
At the moment the stack pipe takes air from the outside (the roof), and
this means that I have a column in a corner of my bathroom.
To save space, and why not to improve insulation, I would like to cut
my stack pipe halfway (say at basin overflow level) and close it with
an air admittance valve on top.
What do you think?

Also, what's the position of building control about this? Is this stuff
regulated?
I'll ask them tomorrow, but BC in my council tends to answer very
randomly. So I guess if I get an answer I don't like I'll try again

Cheers,
Julian

everything's regulated these days... side effect of a Labour government I'm
afraid. i cant see much of a problem with it...afaik, as long as your house
has another stench pipe, you can use air admittance valves. why at basin
level? if i were you id cut as low as poss without interfering with flow
etc.

Steve

"pizza" wrote in message
news

Hi there,

Any experiences with air admittance valves?

I'm refurbishing my bathroom.
At the moment the stack pipe takes air from the outside (the roof), and
this means that I have a column in a corner of my bathroom.
To save space, and why not to improve insulation, I would like to cut
my stack pipe halfway (say at basin overflow level) and close it with
an air admittance valve on top.
What do you think?

Also, what's the position of building control about this? Is this stuff
regulated?
I'll ask them tomorrow, but BC in my council tends to answer very
randomly. So I guess if I get an answer I don't like I'll try again

Cheers,
Julian


--
pizza

If you are going to use an air admittance valve, then why not take your
boxing down to 250mm max? Do not forget to also use the anti-vacuum traps on
the bath / shower and sink! The bathroom will look much smarter without the
SVP stack boxing and you do not have to worry about venting gases. if any
gases are ignited in a sewer, they usually just blow some manhole covers
off...

Lee

On 15 Dec 2004 21:42:43 GMT, (OldScrawn) wrote:

When I wor a lad there were iron "chimneys" in the street, about the same
height as telegraph poles, I was told they were sewer vents. Havn't seen one
for ages though....

You still see these occasionally. When I lived "at home" with the
parents we had a 1901ish town house with a vent pipe some 8' high from
the manhole in the back yard as well as the normal pipe extending some
2' above the gutter on the house.

When I considered fitting an AAV a while ago I contacted the BCO and
was told that since I share a sewage manhole with my next-door
neighbour who still has a normal "stench pipe", this is acceptable,
that is, our communal m/h is adequately vented.

I would _love_ to visit a Victorian-type tunnel sewer!

--
Frank Erskine

On Wed, 15 Dec 2004 22:54:25 UTC, Frank Erskine
wrote:

On 15 Dec 2004 21:42:43 GMT, (OldScrawn) wrote:

When I wor a lad there were iron "chimneys" in the street, about the same
height as telegraph poles, I was told they were sewer vents. Havn't seen one
for ages though....

Got one or two just down the road here (Station Road, Herne Bay, Kent).

I would _love_ to visit a Victorian-type tunnel sewer!

They do trips down the Brighton sewers....

--
Bob Eager
begin a new life...dump Windows!

"Frank Erskine" wrote in message
...

When I considered fitting an AAV a while ago I contacted the BCO and
was told that since I share a sewage manhole with my next-door
neighbour who still has a normal "stench pipe", this is acceptable,
that is, our communal m/h is adequately vented.

Yes, provided one of these is evident at least every few properties; for
buildings in between an AAV alone is OK. When I had this job done some
months ago, I had the AAV terminating within boxing behind the bath, but the
BCO insisted the pipe was extended upwards into the roofspace, terminating
there instead. I think this was a somewhat subjective opinion TBH; it would
be worth the OP discussing it with his BCO to see what's considered
acceptable; if it's the same as mine there wouldn't be a lot of point in
doing the work!

David

"r.p.mcmurphy" wrote in message
...

"pizza" wrote in message
news

Hi there,

Any experiences with air admittance valves?

I'm refurbishing my bathroom.
At the moment the stack pipe takes air from the outside (the roof), and
this means that I have a column in a corner of my bathroom.
To save space, and why not to improve insulation, I would like to cut
my stack pipe halfway (say at basin overflow level) and close it with
an air admittance valve on top.
What do you think?

Also, what's the position of building control about this? Is this stuff
regulated?
I'll ask them tomorrow, but BC in my council tends to answer very
randomly. So I guess if I get an answer I don't like I'll try again

Cheers,
Julian

everything's regulated these days... side
effect of a Labour government I'm
afraid.

Don't be silly. Stop making things up.

i cant see much of a problem with it...afaik,

See the Building Control dept, Usually every 4th or 5th house requires an
open stack.

Thanks everyone.
Though what I'm most interested in I guess is: do these things actually work? Or am I gonna find out in two year's time that it's leaking foul odours and I have to replace it or worse go through the roof again?
Any brands you recommend or I should avoid?

Cheers,
Julian

On Thu, 16 Dec 2004 14:40:39 +0000, pizza
wrote:

Though what I'm most interested in I guess is: do these things actually
work?

They're designed to stop vacuums from emptying your waste traps. This
much they do.

They're not intended to release over-pressure. So complaining that
they don't doesn't really cut much ice.

I can't see myself ever replacing a two-storey stench pipe with one,
but they are useful for flat conversions in existing buildings, or
even for replacing a single-storey stenchpipe if your bathroom is in a
single-storey rear extension to an old terrace.

If you install it in an internal cupboard, then it doesn't need to be
deliberately vented (few cupboards are airtight), but it does need to
have a reasonably large internal volume.

Or am I gonna find out in two year's time that it's leaking foul
odours and I have to replace it

One day it'll stop working. I've seen them (admittedly only a handful)
in service for about 7 years now, and not yet seen a failure.



--
Smert' spamionam

Bob Eager wrote:
On Wed, 15 Dec 2004 22:54:25 UTC, Frank Erskine
wrote:


On 15 Dec 2004 21:42:43 GMT, (OldScrawn) wrote:


When I wor a lad there were iron "chimneys" in the street, about the same
height as telegraph poles, I was told they were sewer vents. Havn't seen one
for ages though....


Got one or two just down the road here (Station Road, Herne Bay, Kent).


Got one in our back garden. It's at least 50% higher again than eye
level from an upstairs window.


I would _love_ to visit a Victorian-type tunnel sewer!


They do trips down the Brighton sewers....


The manhole cover in our garden approx 15ft away from the big pole
exposes steps down to a very small 3ftx5ft approx "room", with the sewer
gully running through the bottom of it.