cooking smells in upstairs bathroom

[sennen]

Hi,
I live in the upstairs half of a pair of new-ish maisonettes. I regularly experience cooking smells from downstairs in my bathroom, which seems to come from my bath plughole. Only cooking smells, never sewer smells. I always take care to ensure bathroom traps are filled after use.

Both maisonettes are roughly the same layout, with the kitchen at the front of the building, a hallway in the middle, and a bathroom at the rear. There's definitely a soil-pipe inside the rear wall.

I have been told by a (long retired) plumber, who hasn't seen the property, that it could be due to the outlet pipe from the bath having a long-ish distance to go to the soil pipe, and that flushing, etc. from downstairs can cause the water in the bath's trap to get pulled out easily - thereby exposing the bath to the smells from below.

I have also been told (by a non-plumber) that it could be due to a lagging problem on the waste pipe in the bathroom.

Do either of the explanations make sense to you all? Is there anything I can do to prevent the smells coming up?

Thanks,
Carl

 

[WHPES]

It is nothing to do with the oulet pipe - if it were the case you would get drain smells, not cooking smells. That you smell it round the plughole is probably coincidence.

It will be air getting in from down below through gaps in the ceiling etc. Take off the bath panel and check for gaps. You could use expanding foam to fill any gaps.

 

[Puddle]

As said. Probably got recessed lighting in ceiling and a gap under your bath, with these recessed ceiling lights now; there is no seal between flats and house levels

 

[REDSAW]

if there is a cooker hood the pipe may go above ceiling and come disconnected.