Hi,

I have a bungalow built in 1950s with a suspended floor and a pitched roof
extension. The extension measures 12ft x 15ft and is heated by a 2ft x
2.5ft single radiator (inadequate, I know). Since moving in 9 months ago, I
have noticed mould growing on curtains / carpet etc particularly in the
extension. The extension is noticably colder than the rest of the bungalow
even though it's directly off the lounge. I pulled the carpet up today and
found that there was white mould (smells mushroom-like) underneath the
underlay on the chipboard flooring - it feels damp. I removed a piece of
the flooring and got a good draught so the air bricks must be Ok. It's just
chipboard flooring - no insulation of any kind. The original part of the
lounge has floorboards and does not feel damp.

What do you reckon - is it a ventilation problem? Should I take up the
chipboard and lay floorboards and hope that improves things? Or does the
floor need insulating - how would I go about doing this? Could condensation
have built up in the chipboard due to inadequate heating?

Any advice greatly appreciated!

Graham.

In an earlier contribution to this discussion,
Graham wrote:

Hi,

I have a bungalow built in 1950s with a suspended floor and a pitched
roof extension. The extension measures 12ft x 15ft and is heated by
a 2ft x
2.5ft single radiator (inadequate, I know). Since moving in 9 months
ago, I have noticed mould growing on curtains / carpet etc
particularly in the extension. The extension is noticably colder
than the rest of the bungalow even though it's directly off the
lounge. I pulled the carpet up today and found that there was white
mould (smells mushroom-like) underneath the underlay on the chipboard
flooring - it feels damp. I removed a piece of the flooring and got
a good draught so the air bricks must be Ok. It's just chipboard
flooring - no insulation of any kind. The original part of the
lounge has floorboards and does not feel damp.

What do you reckon - is it a ventilation problem? Should I take up
the chipboard and lay floorboards and hope that improves things? Or
does the floor need insulating - how would I go about doing this?
Could condensation have built up in the chipboard due to inadequate
heating?

Any advice greatly appreciated!

Graham.

Are the joists wet? What is supporting them? Is it possible that there's a
sleeper wall under the joists which doesn't have a proper DPC?
--
Cheers,
Set Square
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"Set Square" wrote in message
...

Are the joists wet? What is supporting them? Is it possible that there's a
sleeper wall under the joists which doesn't have a proper DPC?
--
Cheers,
Set Square
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Please reply to newsgroup. Reply address is invalid.



You are spot on! The joists are wet and they do appear to be supported on a
sleeper wall. How should I damp proof this? Can I lay a damp proof
membrane directly under the joists?

Thanks,

Graham.

It is unlikely that your mouldy curtains, or indeed the majority of
symtoms you are suffering in the room are the result of anything other
than condensation.

Which elevation is the extension on - North, North East? or is it in a
particularly windy environment?

Also, being built in the fifties, It will have dreadful u values in the
walls and floor which aren't going to help.

Heat it better, ventilate it better (does it have PVCu double
glazing?), generally follow all good guidelines to combat condensation
and your mould will disappear.

If you do indeed have wet joists this could be caused by a lack of damp
proofing on the sleeper wall, as SS suggests. Howver, if this is so,
it's an error on the builder's part and, to be honest, if you've had
wet joists sincer 1950, you're very lucky you haven't got any kind of
rot. You should check on top of the sleeper walls for a black
substance between the brickwork and the timber, probably plastic but
maybe bituminous which is acting as a dpc. If you can't see it, the
sleeper walls may be built directly off the oversite and they've put a
dpm beneath that.

If you really haven't got any form of dpc then you're going to have to
slightly jack up east joist (quarter of an inch or so) in the vicinity
of the sleeper wall and slip a piece of dpc between the wall and the
joist - no big deal. To be honest, this is unlikely, it's more likely
to be sub-floor condensation.

If you can hire (beg, borrow,steal) an electronic damp meter, your
joists should have a mosture content of less than 22%. Ideally it
should be less than 20% but sub floors are never ideal places and
they're usually on the high side. Don't use it on the walls, you'll
frighten yourself with the levels of condensation you obviously have

If you want any more info on condensation, email me directly and I'll
give you the url of my website.

HTH

Xav

Have alook and post back