Damp problem...

[dirty boy]

Been in the house a few months now, and we're now getting damp/mould in one corner of our bathroom (upstairs) next to the toilet.

It's an old house 100+ years old, but this is in the extended bit, which I would guess is around 50 years old, not rendered.

Is it just condensation? I think perhaps there may be some water must be getting in near the pipes behind the toilet, as it's expanding from there (I've let it go a week to see how it grows - disgusting huh!)

Is a dehumidifier my only real option here otherwise? I could leave windows open, but that's not exactly a cure.

[Wings]

Mould will form on the coldest spot, so ceiling that lacks insufficient insulation, hot moisture will rise, hitting (cold) ceiling below roof space, where mould will form/flourish. Either insulate in roof space, or increase ventilation, otherwise regularly clean with bleach and touch with paint.

[V12Les]

Very common on older properties. Very cold water coming into a warm house=condensation. If you can see if its possible to lag any of the pipework, may help to a degree.

[rovermorris999]

Almost certainly due to condensation. Fit an extractor fan that stays on for a while after you switch it off, if you get my drift.

[Wings]

rovermorris999 said:

Almost certainly due to condensation. Fit an extractor fan that stays on for a while after you switch it off, if you get my drift.

Good suggestion, particularly fan extracting to loft space,…..but rented accommodation, so OP needs to put that to the landlord/agent.

[dirty boy]

Wings said:

rovermorris999 said:

Almost certainly due to condensation. Fit an extractor fan that stays on for a while after you switch it off, if you get my drift.

Good suggestion, particularly fan extracting to loft space,…..but rented accommodation, so OP needs to put that to the landlord/agent.

Not rented.

What about this http://www.solarventi.co.uk/index.pl?section=7

Any thoughts??

[TooLateForAName]

have a look outside at the guttering and pointing.

Do *not* fit an extractor into the loft space unless your loft space is very very well ventillated.


consider mhrv

[rovermorris999]

Surely nobody vents direct into a loft space? It should be ducted out at the soffit.

[Wings]

rovermorris999 said:

Surely nobody vents direct into a loft space? It should be ducted out at the soffit.

Vent through ceiling via loft space, out through soffit or roof.

[HiRich]

Wings said:

rovermorris999 said:

Almost certainly due to condensation. Fit an extractor fan that stays on for a while after you switch it off, if you get my drift.

Good suggestion, particularly fan extracting to loft space,…..but rented accommodation, so OP needs to put that to the landlord/agent.

Because it's the bathroom that's the problem, I would agree with an extractor. Take a browse at Vent-Axia. I would suggest:

• One with both timer and humidistat (stays on after the lights are used, and also fires up independently when the humidity rises). Tricky to set up well (lots of tweaking the dials), but they work rather well once you do.
• One with an actuated non-return shutter incorporated in the fan unit. Less draughty when the wind comes from the exit side, and you don't get the exterior shutter falpping in the wind.
• One of the loft-mounted units, rather than on/in-wall units. Quieter, easier to install, easier to replace (eventually), tidier, and the inlet can be placed right over the source (bath/shower). But it ultimately has to be vented out of the building, ideally on the leeward side of the building.
• Add an isolator switch by the bathroom door - sometimes you want a bit of piece and quiet.

This may not totally solve the problem, but it will improve it significantly.

[dirty boy]

Thanks for the comments, quite concerned by this, never had any problems at the old place, I've even got condensation in the loft too, but I suspect that's because my loft hatch doesn't fit very well (must sort that!)

Wall mounted dehumidifiers are huge, I think that'd be ideal, but will go with the extractor.

[TooLateForAName]

I've just bought a vent axia HR25H - It isnt fitted yet so I cant give feedback on how effective it is, but it isnt too big compared to a normal fan (6" rather than 4" hole)