Making anti-mould bathroom

[Authenticity2020]

We are finally having our bathroom redone in August, the shower was leaking and even without that we had a huge mould problem, despite having an extractor fan ducted to the outside.

Does anyone have any tips? Was thinking anti-mould paint for ceiling and maybe find out if underfloor heating is expensive, it sounds it though. X

@SwedishEdith I’ll check for YouTube vids, do you have a link of the one you saw? Mould spray definitely did a number on our sealant!

Sorry, meant to add the link. This one

Looks like not working but search this one and it's Charlie someone: 'How to Paint over Mould & Mildew'.

@SwedishEdith thanks I’ll check it out now

for bathrooms, tilers now often use a waterproof cement-based backing board instead of plasterboard. there is a version incorporating a layer of insulating foam.

It does not seem very thick. If you have old solid walls, and can lose a few inches, I'd consider drylining the walls with rigid foam then the backerboard next time you have it tiled. If the tiles are warm they will not attract condensation.

I have CWI and a good fan, and the walls are free of condensation even in winter

Fibreglass shower cubicles are supposed to be the easiest and leak proof. No grout, or silicone to seal gaps for example.

@PigletJohn what is CWI? And would you recommend underfloor heating in a bathroom and a shower room?

CWI = cavity wall insulation

UFL is quite expensive to install, if wet, and expensive to run, if electric. In a new build or extension where a new floor is being laid, wet UFH is worth considering.

For a small bathroom or shower room it is pleasant on the feet and helps dry bathmats and even towels that have been dropped on the floor.

I am not keen on tiles on a wooden floor, and definitely not on chipboard, because the slightest movement will crack the grout.

Zinsser anti-mould paint is good.

Looked into HVAC or MVHR as they have in "passivhaus" buildings (German standard for eco-buildings that are super-insulated and air-tight), but very expensive to retro fit to an old property, and not as effective as in a new build.

As a compromise solution we have a small heat recovery extractor fan which uses heat in the air being extracted to warm the incoming air, so saves energy. Needed a bigger hole (6 inches as opposed to 4 inches) and cost more than a normal extractor fan. Ours is a Kair. Other makes are available. It constantly monitors humidity and trickle vents air - keeps small house mould free. You have to get a qualified electrician to fit it because electrics in bathrooms.