Damp in bathroom - a few questions

[Jethro]

With increased use (teenage lad start seeing girls) our bathroom is clearly not properly ventilated - black mould seems to build up everywhere.

Current ventilation is a fan, which came with a shower light. It's only a small thing, so not up to the job.

I am reluctant to start punching more holes in the ceiling, and mounting a fan to the outside wall is not possible. Could I get away with replacing the current fan with a more powerful one ? Assuming the new fan is bigger, would using step up/down adapters be viable ?

Once the ventilation is sorted, what's the best way to deal with the mould that has gotten into the grouting ?

[TMC]

Open the window?

[Andrew Gabriel]

Can you describe exactly where the mould is?

On ceilings, and corners particularly, it could be due to cold spots due to lack of insulation behind.

In showers, it won't grow directly on tiles or grout, but it will grow on the soap scum which can thinly coat these. A descaling cleaner will remove this, and using liquid soaps rather than bars of soap will reduce the build-up in the first place. If the grout is porous, then food for the mould can soak into it. Try cleaning the grout using a plastic scourer to see if the mould is just on the surface, or if it's penetrated into the grout. Make sure the scourer is either not coloured (available from tile shops) or is same colour as the grout, or it may stain the grout with colouring.

With regards ventilation, check the fan will draw a piece of paper onto the grille. Does the room have an air inlet somewhere? Does the fan have a run-on timer, and how long does it run-on? It seems unlikely to me that a larger fan is required.

[NT]

Also regular bleach cleaning will deter mould, and walls/ceilings etc can be treated with a mould preventer.

NT

[Tim Lamb]

In message , NT writes

Can you extend the extract fan *run on* time?

regards

[Jethro]

The most apparent is in a patch, just above the shower. However there are rings of mould around the taps, *in* the taps (the little plastic widget they put in to aerate the water), along the grouting (especially near the bath). The shower nozzle and outside of the hose too.

I'll check the roof insulation tonight ...

I've tried bleach and a nail brush, but the discolouration hasn't gone.

The fan's run on is on maximum (about 15 minutes). It can hold a piece of paper up. There's no express air inlet into the room, but the door is left open most of the time (except when in use, obviously).