Strange weed/old beer smell from attic/bathroom

chamelious

Just moved into an old terraced house and we have a weird intermittent smell that seems to come from the attic, but is also particularly noticeable in the bathroom below it, and a bit in the hallway where the attic hatch is, but not really the other upstairs rooms.

Haven't pinned it down to any specific situation, woke up to it this morning after a relatively calm, rain free night, heatings been off for 72 hours.

Only thing i can think/find is maybe the neighbour is actually smoking weed, i know at least one of them does have an attic room. When we moved in the attic had a load of junk in it, which has been tipped for a week or two, didn't notice anything out of place up there.

Norman_Castle

Try blocking any gaps in the party wall between the lofts. Pushing bits of loft insulation into them works.

After doing this check through the winter for damp or mold. Blocking the gaps may decrease the ventilation.

chamelious

Thanks, i think the ventilation will be ok as there is clear air space under the rafters. You think the smell coming from next door is likely? Tbh i thought it was a long shot.

Norman_Castle

If you've got decent access in your loft it won't take long and will eliminate next door as the source.

I've got a soil stack running through my loft which until recently was incorrectly fitted to a standard roof vent. A soil stack pipe should extend above the roof. I had a musty smell in the loft which I blamed on two vast, 100 year old birds nests. After removing the nests the smell was still there. I noticed that air was entering around the air vent the soil stack was fitted to. I had an internal cap fitted (air admittance valve) to the soil stack which allows air in but not out. The smell in the loft has now gone.

chamelious

Thanks, i'll try that.

Thanks for the info but theres nothing like that in my loft unfortunately. Just a standard unused chimney and boards and insulation!

lstar337

They could also be growing it. Keep an eye on your electric meter to make sure they don't tap off of it.