Damp smell in extension to modern house

[John Kelly]

No there isn't. Like I say the building inspector did his usual turn up, have a cup of tea, chat to the builders, and leave. Do they inspect anything? Having said that he did insist the footings went down about twice as deep as the builders had dug them so maybe he just knows what t look for.

It's bone-dry under the polythene. I've also put a newspaper on the floor to see if it gets damp. After one night it's also dry.

Which, by chance, having come from a damp house previously, we have in storage somewhere. Never thought I'd be digging it out for a new extension though. I'm hoping that this is just damp from the building process and once it's all dry then it won't need any more drying out.

Today it smells fine. Is it a co-incidence that yesterday was bucketing down all night and day and today it isn't and yesterday it stunk of damp and today it doesn't?

[djc]

Where does the rainwater go?. Leak in gutter, down pipe, drain disturbed by new foundation?

[John Kelly]

Should be okay as the drain is all new. I'll lift the drain cover and make sure it is all going where it should be. Bit stuck for time now as (unfortunately my lottery numbers didn't come up) I've got a weeks work to do :-(

[robert]

You can get a very funny - musty/rotting smell from overheated plastic light fittings.

I spent several months trying to track down the source of a damp/rotting smell in my extension which came and went , before discovering the slightly brown bayonet light fittings.

Robert Robert

[Tournifreak]

According to the BBA it can be, depending on the design and construction of the roof. See here:

our new roof has no additional ventilation - our builder appeared to be under the impression that this was very common practice these days.

Jon.

[Bob Mannix]

> Certainly, our new roof has no additional ventilation - our builder

It is, we have just (2002) had an (excellently constructed) extension finished. Breathable membrane was on the approved plans and passed on the building with no additional ventilation.

[John Kelly]

>>> Certainly, our new roof has no additional ventilation - our builder

Thanks for confirming that it's okay in that respect. I was getting a little worried...

Since sunday morning (the rain stopped) it's been absolutely fine. Smells perfectly normal in there now.

[IpsoFatto]

replying to robert, IpsoFatto wrote: Hi, I hope you don't mind me reactivating this thread - I just came across it and @John Kelly's issue describes exactly a problem we're having with a garage extension we had done.  I wonder if you might be able to tell me if you were able to resolve this and if so, how?Any advice would be much appreciated - we're at hte point of considering a surveyor to come around and do an investigation as the smell in humid weather is so strong, while the rest of the time, there is absolutely no smell at all.  It's very odd. Grateful for any advice!

[tabbypurr]

You should find online diagrams of all the usual sources of water. Just che ck for them.

NT

[Brian Gaff (Sofa)]

Were any pipes or inspection covers etc, moved when it was built to allow them to still be accessed. However the only in humid weather sounds more like a leak that will not dry due to the high humidity periods. Could be some kind of organism is present. Brian

[harry]

Probably just the smell of new plaster and cement. Get yourself a de-humidifier. It'll probably fix the problem in a few days.

It must be run with all the windows and doors shut.

[tabbypurr]

pointless in this weather!

NT