where is this mould and mildew coming from?

The kitchen is extended so three outside walls. In the corner nearest the original house wall there is black mould. It is getting worse.

I have used a bleach solution several times to no avail, it is actually getting worse!

I have lived in this house for 30 years and never had this problem before. I have checked on the neighbours side but there are no downpipes or other water problems that I can see.

There are no water pipes under the floor at that point, the washing machine , sink and dishwasher are on the other side.

Could it possibly be from the roof if there was a small leak? If that was the case should the mould not come from the ceiling down, this stuff is from the floor up.

I am baffled!

Any suggestions?? Many thanks.

Re: where is this mould and mildew coming from??

Could be rising damp prob.... is there a step outside at this place.. if water can get in above your damp proof course that could be prob... had this ourselves and simply sealed the step up properly and problem went...

when an extension is built, there really should be an expansion joint constructed where new meets existing, this is almost never done.

The new build will move independantly of the existing and invariable cracks and gaps will appear between old and new. It sounds to me like water is coming in through here.

see pic:
http://i48.photobucket.com/albums/f242/sydthebeat/newblock.jpg

My advice would be to engage an architect / engineer to survey the property and advise on best remedial work. Mould / fungi has health implications.