Condensation and Mould in Loft of New Extension Information, help and tips on many areas of roofing including trusses, tiling, venting, insulation etc....

[Damp Patch]

We have had an extension built, completed around 3 months ago. The loft (which is seperate from the rest of the house) has suffered from a lot of condensation. The builder assures me it is normal but he does make stuff up. Recently I noticed mould forming on the rafters, so I put a fan in the loft hatch and opened up an indoor window nearby to allow air to flow through to reduce moisture. It has got rid of most of it but I am concerned that the cause of the problem is still there - perhaps lack of ventilation?

The under-felt is Til-R Breather Membrane and I'm told soffit vents are not required. So my thoughts are;

1) Is excessive condensation & mould normal in a new build?
2) Is it temporary while moisture escapes, or is there an underlying problem?
3) What remedial action (if any) should be taken?
4) And additionally, is the extractor fan fitting a bodge?

Thanks in advance!

Some of the remaining Condensation

Mould forming

Temporary ventillation

Is this a bodge?

[welsh brickie]

I would install soffit vents, there is obviously not enough ventilation into the space.
Its hard to see if the vent is a bodge