Damp and Mould

Katie-Kat-Kins

Hi,

I'm looking for some advice on how to get rid of mould and prevent it from recurring.

Our house has three electric storage heaters for heating and some panel heaters for top up heating.

In winter we get problems with condensation on the windows and black mould on the bathroom ceiling, and a little bit where the wall meets the ceiling on the external wall in one of the bedrooms.

We have an extractor fan in the bathroom which we use whenever the shower is on.

We dry washing indoors in one of the bedrooms, but not the one with the mould.

Last winter I got a dehumidifier, but it doesn't seem to be making much difference.

So what I can I do to stop this problem getting worse? I'd like to have a strategy before the really cold weather arrives. Plus I'm sick of seeing the black marks on our bathroom ceiling everytime I'm in the shower!

I should add that it is a ten year old house with double glazing. Some of the windows have trickle vents, and those which don't are left in the locked open position which allows some venting.

Thanks

WestonDave

Re the bathroom. Check there is sufficient loft insulation above it so the ceiling is kept as warm as possible. Change the extractor fan for a humidistat one (this detects damp air and keeps running until it clears) - if yours is turned off after you shower or after five minutes then most of the moisture is left in the room. Consider opening the window and leaving the door shut for say half an hour after you finish with the bathroom (while you have breakfast etc).You need to get all the moist air out of the bathroom.

In terms of the bathroom ceiling - we had similar problems albeit just with the last bit of ceiling nearest the wall - which was always colder. We used to have to bleach the mould off every few weeks. We then painted it with some Zinsser Perma White paint which has a mould inhibitor in it - the small can which is about £16 should be enough to do the two coats you need (its a two layer process so needs two coats) - ours has stayed clear since we did ours in January. Alternatively you can get anti mould additives for normal paint but they are normally about £7 anyway plus you will need the paint, so for a small area like this its probably worth getting the Zinsser paint. You can also run this along the affected edge in the other room.

To resolve the rest of the issues you need to confine the moist air - keep the bathroom door shut (fan on and window open) so the steam from the shower goes out not into the rest of the house. Likewise with the room you are drying washing in. I'd guess that the other room with a problem is the one you sleep in - if so you need more ventilation to get rid of your breath! That will be building up moisture in the room.

Katie-Kat-Kins

WestonDave wrote: »

Re the bathroom. Check there is sufficient loft insulation above it so the ceiling is kept as warm as possible. Change the extractor fan for a humidistat one (this detects damp air and keeps running until it clears) - if yours is turned off after you shower or after five minutes then most of the moisture is left in the room. Consider opening the window and leaving the door shut for say half an hour after you finish with the bathroom (while you have breakfast etc).You need to get all the moist air out of the bathroom.

In terms of the bathroom ceiling - we had similar problems albeit just with the last bit of ceiling nearest the wall - which was always colder. We used to have to bleach the mould off every few weeks. We then painted it with some Zinsser Perma White paint which has a mould inhibitor in it - the small can which is about £16 should be enough to do the two coats you need (its a two layer process so needs two coats) - ours has stayed clear since we did ours in January. Alternatively you can get anti mould additives for normal paint but they are normally about £7 anyway plus you will need the paint, so for a small area like this its probably worth getting the Zinsser paint. You can also run this along the affected edge in the other room.

To resolve the rest of the issues you need to confine the moist air - keep the bathroom door shut (fan on and window open) so the steam from the shower goes out not into the rest of the house. Likewise with the room you are drying washing in. I'd guess that the other room with a problem is the one you sleep in - if so you need more ventilation to get rid of your breath! That will be building up moisture in the room.

I think insulation may be the problem, we have very thick loft insulation, except over the bathroom, where the electrician had to take it up when he wired in the shower, extractor and recessed spot lights because of the risk of fire.

Any suggestions?

It is probably made worse because we don't have heating in our bathroom either.

But we do leave the extractor going for a good while after a shower, and ALWAYS have the window open a crack 24/7.

You are right that the other room is the one we sleep in, but we have a trickle vent on one window and the other is left open a crack 24/7, I think having a window open any more would lead to an unpleasent draft at this time of year. I suppose we could make sure we leave the door open to the rest of the house as an alternative.

I'll look for that paint though - thanks for that!

Norman_Castle

I use rentokil Tri-spot on the ceiling part of a dormer window in my bathroom. Before using this the ceiling would be covered in mould every winter, it is now mould free. I am not sure if is still avaliable. I tried google-ing it and nothing came up. It is a biocidal wash. I expect it is still made under another name.

WestonDave

Get some of these - http://www.screwfix.com/prods/97932/Lighting-Lamps/Internal-Lighting/Fire-Rated-Downlights/Fire-Hoods/Halolite-Downlight-Fire-Guard-220mm

to put over the lights - then you can put insulation over the top. We've put the slightly bigger (and more expensive) versions from the same site because we wanted to be absolutely sure that there wasn't too much heat build up. You can put insulation under the shower cable as long as you let it have plenty of air to stop it overheating - it might be worth putting some insulation in between the joists then putting some board (hardboard would do) over that with the cable on top so the cable doesn't sink into the insulation.

To be fair with the room you are in, its not a big problem - its probably just the cold strip where the insulation doesn't reach in the loft - not that much you can do about that other than use the paint. You won't find it in B&Q - I got mine from a decorators merchants - if you google for one in your area.

Katie-Kat-Kins

Brilliant! I thought there must be some sort of solution so that we could insulate the area again. I'd been thinking about something like that, but didn't want some homemade version to cause a fire hazard, I'll buy some of those and get them fitted asap.

savemoney

Yes sounds like insulation is the main problem we use to get it in old house due to insulation not going into the far reaches of the roof

I also when I wallpaper I line the outside walls with polystyrene paper it helps a little. Maybe for ceiling put some bathroom paint on it. Its suppose to be more resilient to condensation. Dulux do one we used it in our bathroom walls so far so good outside walls dont get as we when we showered although we also replaced the extractor at same time so that will probably help a little

Katie-Kat-Kins

It is bathroom paint, and the extractor is less than two years old!

The problem started when we had the shower fitted, and at the same time the recessed lights and new extractor. Prior to that the extractor was faulty, but we had full insulation and no shower!