Moisture in loft and OsmaVent

[Hozier]

Hi.

This last few months we've noticed a musty smell in the loft and pretty much all of the roof membrane (if that's what you call it) has little condensation drops on it.

Not sure what is causing this as it's never happened for the previous 9 years but I will be double checking extractor vents e.t.c.

Today though I noticed a particular wet patch on the floor (insulation and board) which surrounds the OsmaVent 110 4S304 and some of the vent looks discoloured.

What does this mean, and how do I deal with it? Could this also be the source of the condensation issue or is that a different player?

Thanks.

 

[Hugh Jaleak]

The Osma part is an air admittance valve (AAV), should o exactly as it says on the tin and let air in, but not out. Possible its stuck open and is allowing steam/vapour out into the loftspace which is then condensing and going towards causing your issue, but I wouldnt say its entirely at fault, (and that is assuming it has stuck open.) I would check for any other possible issues and also make sure there is adequate ventilation in the eaves, and insulation isnt blocking any soffit vents.