Extractor fan ducting
MarkK
kitchen ceiling, which is plasterboard, and a bedroom floor, which is T&G
floor boards?
I'll be using 125mm ducting. I'm primarily concerned about building regs &
fire risk, but would guess the temperatures involved shouldn't normally be a
problem. The joists run in the right direction and there are no
obstructions, so in principle it looks straightforward.
I'm planning on buying the ducting from Screwfix.
Any advice, or alternative suppliers would be appreciated.
Mark
JoeJoe
"MarkK" <ma...@alslskdjfasdf.co.uk> wrote in message
news:V46dnT856a0...@bt.com...
http://www.kiltox.co.uk/shop/en-gb/dept_21.html
David Hansen
<ma...@alslskdjfasdf.co.uk> wrote this:-
>Is it OK to run 3m of extractor ducting (for a cooker hood) between the
>kitchen ceiling, which is plasterboard, and a bedroom floor, which is T&G
>floor boards?
Will this pass through any walls, other than the external one.
From what materials will the ducting be constructed?
>I'll be using 125mm ducting. I'm primarily concerned about building regs &
>fire risk,
Is the ceiling and/or floor designed to be fire resistant? If so,
for how long?
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54
Ian_m
box. He has seen numerous cases where the extractor hood fan motor has
caught fire (possibly due to dirt and grease) and the fire then passed
through into the ceiling space before entering the room above.
The boxing was made with plasterboard (spare bits of 15mm sound block
plasterboard in my case) with gaps sealed with fireproof mastic. There were
a couple of peices of wood (to hold the plasterboard in place) in the
cavity, which were covered with expanding fireproof foam.
I got the mastic and foam from Travis Perkins, but I notice Screwfix sell
also.
Also fitted an intumescent collar to a waste downpipe passing through the
kitchen (behind boxing) as he has seen a kitchen fire pass into the down
pipe and get into the room above. The collar crimps the pipe off from the
heat of a fire, again Travis Perkins.
MarkK
"David Hansen" <SENDdavi...@spidacom.co.uk> wrote in message
news:kq79b2p0f074ugmnq...@4ax.com...
> On Wed, 12 Jul 2006 00:09:33 +0100 someone who may be "MarkK"
> <ma...@alslskdjfasdf.co.uk> wrote this:-
>
> >Is it OK to run 3m of extractor ducting (for a cooker hood) between the
> >kitchen ceiling, which is plasterboard, and a bedroom floor, which is T&G
> >floor boards?
>
> Will this pass through any walls, other than the external one.
No
> From what materials will the ducting be constructed?
Not finalised, but how about:
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=59769
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=17489
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=72110
> >I'll be using 125mm ducting. I'm primarily concerned about building regs
&
> >fire risk,
>
> Is the ceiling and/or floor designed to be fire resistant? If so,
> for how long?
I don't think either ceiling or floor above are designed to be fire
resistant. House is 1950-built 2-storey.
MarkK
news:R9OdnZkXxbuUfynZ...@tcp.co.uk...
Mark
David Hansen
<ma...@alslskdjfasdf.co.uk> wrote this:-
>> From what materials will the ducting be constructed?
>
>Not finalised, but how about:
>http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=59769
>http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=17489
>http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=72110
Couldn't you just say?
Assuming the flexible ducting is metal then I see no problem. Make
sure it slopes down gently to the terminal. I certainly wouldn't
bother with intumescent collars.
Lobster
> My brother, a building consultant, put my kitchen ducting in a fireproof
> box. He has seen numerous cases where the extractor hood fan motor has
> caught fire (possibly due to dirt and grease) and the fire then passed
> through into the ceiling space before entering the room above.
If one guy has genuinely seen numerous cases that implies this is a
really common problem. How many is 'numerous'? I've never heard of
this issue.
David
MarkK
> On Wed, 12 Jul 2006 23:45:41 +0100 someone who may be "MarkK"
> <ma...@alslskdjfasdf.co.uk> wrote this:-
>
> >> From what materials will the ducting be constructed?
> >
> >Not finalised, but how about:
> >http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=59769
> >http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=17489
> >http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100139&ts=44140&id=72110
>
> Couldn't you just say?
I could've said "plastic & metal" but for all I knew you may have wanted to
know the type of plastic, etc. Linking to the items I'm considering allows
people to respond with "they're fine" or "don't use that" type responses.
> Assuming the flexible ducting is metal then I see no problem. Make
> sure it slopes down gently to the terminal. I certainly wouldn't
> bother with intumescent collars.
By terminal I assume you mean the outlet to atmosphere, and that the sloping
down is to allow any condensate to drain away from the extractor unit?
Mark
David Hansen
<ma...@alslskdjfasdf.co.uk> wrote this:-
>By terminal I assume you mean the outlet to atmosphere, and that the sloping
>down is to allow any condensate to drain away from the extractor unit?
Correct on both counts.
Long vertical runs of ducting should have traps and drains, largely
because water and normal electric motors don't mix, but also because
water dripping out of the hood is not appealing. However, there
should be no problem with a short vertical run to the ceiling and
then a constant downward slope from there.