I live in a flat with an internal bathroom. It has an extractor fan that
seems to be able to prevent the bathroom from steaming up very well, but
somehow seems to suck in fumes from other bathrooms in the same block.
Looking from outside we seem to have an outlet on the outside wall (about 3m
from the bathroom) on each floor but still we are getting smoke fumes from
other flat's bathrooms.
We have an Xpelair extractor which has a flap behind the fan that only
flaps 'outward' thus
preventing air from coming in. We can only smell smoke coming in when the
extractor is on - when it is off there is no problem. The extractor is
sucking air out, but I assume not very efficiently.
My question is, is it the extractor that needs replacing or do I need to put
some sort of backdraft "preventor" behind it? My innitial though is that
the extractor needs replacing since the problem only occurs when the
extractor is on so maybe it is just not powerful enough, and the exhaust
from other fans in the block is coming back in through mine.
Any thoughts?! Any help appreciated.
What do you mean by 'smoke fumes'? No bathroom should be emitting smoke!
What actually comes back in?
If a fan is extracting, no matter how poorly, then it is very unusual for
any air to be coming the opposite way through the duct. If the fan is
pushing out, then air can not push back in.
The ducts should not be shared, unless there is a communal fan serving all
ducts from all flats - which clearly does not apply to you.
You say that there is a vent from all flats, which indicates individual
ducts. Now it is most unusual for someone else to be using their bathroom
every time that you use yours and so push 'fumes' back into your property.
I would get your fan checked to make sure that the smell is not actually
coming from the unit itself.
Thanks. I mean smoke as in cigarette smoke.. Sorry for being unclear! It
doesn't happen everytime, but if we leave our fan on for a period of time
then we nearly always end up with the smell of cigarette smoke in our
bathroom. I agree that it sounds like the ducts are individual, but maybe
the ducts I can see on the outside are from the boiler and not the
bathroom - I was assuming that the bathroom and kitchen shared the same duct
but this may not be the case.
Ok, that's more likely. I have seen shared ventilation ducts and they were a
You often come across them in hotels...
I can see no possible solution other than increasing the power of your fan
to keep the neighbour's fumes out.
Cigarette smoke would have to be in a very large concentration to get in
through the duct from outside, plus I can't see how it could get in as to be
detectable if the fan is extracting out.
Is there any other way the smoke could be getting pulled into the room by
the fan - i.e. through any gaps in walls , behind units etc? If the fan is
extracting it is pulling air into the room, and this air could be containing
Some of our high-rise flats had problems with cooking odours getting in
through open joints and cracks between wall and floor concrete panels. These
were hidden behind timber panels and cupboard units and were hard to trace.
We initially thought it was due to close proximity of vents and open
windows, but this was not the case.
If you are in a flat then any ingress of smell is potentially serious as the
flats should be compartmentised in case of fire in an adjacent flat. If
smoke is getting in then so could smoke and flames from a fire.
You should have a service agreement with a management agency for repairs to
the structure, and I would contact them without delay to investigate.
| Thanks. I mean smoke as in cigarette smoke.. Sorry for being unclear!
| It doesn't happen everytime, but if we leave our fan on for a period
| of time then we nearly always end up with the smell of cigarette
| smoke in our bathroom.
The air that the fan extracts from the bathroom has to be replaced from
somewhere. Possibly it is being replaced, not by air from your own hall, but
by air being sucked from an adjacent flat. I'd have a look at the boxing-in
of pipes esp the soil stack and underneath the bath panel.
Thanks to everyone for their help. The problem is with the air being sucked
in from another flat - the cistern is kind of built into the wall, taking
the cover off of this there is a strong smell of smoky air. I can't see
where all of the pipes go but I assume that the sewage pipe at least must
join up to other sewage pipes in the block and there is probably not a
complete seal between each flat. Would my management company being legally
abliged to do something about this or is this normal?
Thanks again to everyone who replied.
Chris Green wrote
| Owain wrote:
| > The air that the fan extracts from the bathroom has to be replaced
| > from somewhere. Possibly it is being replaced, not by air from your
| > own hall, but by air being sucked from an adjacent flat. I'd have a
| > look at the boxing-in of pipes esp the soil stack and underneath the
| > bath panel.
| Exactly what I've just said (differently)! :-)
A combination of great minds and off-line newsreaders.
Sure the fumes aren't coming through the floor or ceiling, and by
activating the fan you're sucking them through?
Could try with the door open and see if that fixes it - otherwise
you're sucking the air out of a room; it's either going to come in
from *somewhere* or your bathroom will implode.
Simon Avery, Dartmoor, UK
uk.d-i-y FAQ: http://www.diyfaq.org.uk /
Well, if it is, the chances are that you have a path to the other rooms
via some unseen pipe run or somesuch. The fan must be sxtractingf, so
where is the air getting IN to the bathroom?
You are supposed to have e.g. a hole in the door, or a gap underneath,
to let air in from the rest of your property. If it ain't there, the air
will come from wherever it can. Possibly over a ceiling void, through
holes punched in walls and floors for pipes etc etc.
A few weeks ago, there ws this terrible smell in a room with and
extractor...traced it to a giant puppy turd miles away up the hall. Yup.
Thats how far the air had moved towards te extractor..
I would guess that it's odds on that when the extractor is sucking air
out of your bathroom, air is being sucked in somewhere else in your
flat and it's the sucked in air that carries the smells. So no amount
of messing about with the extractor is going to fix the problem.
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