Terrible Condensation on walls = Mould ... Any help?

[BetterBetter]

Hey,
We have lived in our property for nearly 6 years and every winter we have a terrible problem with condensation on the walls. We have problems in the back and front bedrooms. The walls just drip with water and if the wall is covered with a piece of furniture it gets considerably worse. We try to wipe it every day, but we still get mould growing on the walls.
It’s terrible, we all live busy lives so it’s just impossible to move the furniture every day to wipe the walls down, so we try to do it every week which is just getting ridiculous. It’s so bad that even where the curtain hangs over the wall a little, the area where it’s covered is covered in mould and soaking wet.
It only appears on the outside walls, and we try to ventilate the room as much as possible. Both rooms have vents that are left open 24/7 and we leave the windows open in the rooms as much as possible.
Anyone have any solutions where we can sort this problem out? I have been told about putting polystyrene on the walls where we get the problems as this will warm the wall up and sort out the problem, but I’m not sure if this will work, we have tried many things in the 6 years to try and sort the problem but nothing seems to work (We have tried stripping the wallpaper and just painting on the walls, tried a humidifier ...)

Any help will be greatly appreciated!

 

[JohnD]

you say you leave the ventilators open all the time? so where is the water coming from?

you don't drape wet washing about the house, do you?

//www.diynot.com/wiki/building:condensation_in_houses

 

[BetterBetter]

you say you leave the ventilators open all the time? so where is the water coming from?

you don't drape wet washing about the house, do you?

//www.diynot.com/wiki/building:condensation_in_houses[/QUOTE]

Hey, thanks for replying!

Well thats the thing, I have no idea where its coming from, and the silly thing is the ventilator is right next to the worse area where we get the condensation in one of the rooms!

We have recently got a new roof, so we know that's perfect but it has done nothing to stop the condensation.

The washing is a big no, we actually have our tumble dryer in the shed so I don't think washing has anything to do with it really.

As I said, its worse where furniture is hiding the wall, such as behind a mirror and it's only on outside walls.

Do you think the polystyrene sheets on the wall will help to warm the wall and therefore get no condensation?

 

[Nige F]

what sort of vent are you describing ...Window vent -hole in wall . Also is it a cavity wall construction ...or one of the ex- NCB (coal board) framed houses.

 

[JohnD]

have a look for sources of water described in the article I linked

usually washing, breathing, showering without extractor fan, unvented drier, can also be from wet under floor; gas heater with faulty flue, plumbing leaks including radiators, damp walls due to breached dpc or earth piled up on it, steamy water tanks in loft, condensing boiler emitting water. Is the loft wet or ventilated?

 

[FLIPPINeck]

invest in a good dehumidifier its surprising how much water it`ll take out of the atmosphere.......................

 

[BetterBetter]

Cheers guys for the replies.

I'm talking about a hole in the wall type vent.

The wall is also not a cavity wall constrution.

I have looked at all in that list (and have done for a few years) and still it keeps happening.

I have also invested in a dehumidifier that we have on as much as possible, and though it takes a hell of alot of water, it still ends up on the walls!!

I have been told that the reason why this is happening because its warm air from indoors hitting the cold wall, could this be true? and if so, would the polystriene sheets work to stop the consendation?

 

[malshep]

BB,
One thing that makes a surprising difference is keeping the bathroom door closed while showering/bathing. Not always comfortable if you haven't got heating in there. Also, after you've finished, keep the door closed until the bathroom is fully dried out (at least an hour)

If you're really sure you've got rid of all the water vapour you can, then insulation on the cold walls is the next thing. We used to have polystyrene liner on the walls at home 40years ago. Pretty good as I remember except that it is very easily dented, which means that if you have wallpaper over the top, the slightest knock actually punches a hole straight though the wallpaper! However I've looked everywhere on the internet and can't seem to find plain polystyrene liner available anywhere these days.

Your only option as I see it is Wallrock Thermal Liner. Never used the stuff myself but it is well reviewed. Sold at various prices (mostly ridiculous) but I've seen it for £40 a roll. That makes it about £6 per sq.metre ! Very expensive I know but the alternatives are even more so eg to line the inside of your walls with insulated plasterboard costing many £100s or else to clad the outside of your home costing many £1000s.

If you've struggled for 6 years, I would think your next step is to buy a roll and give at a try in one room!

PS Reading your posting again, are you sure the water isn't soaking through from the outside of a badly pointed wall (no cavity to stop it)

 

[malshep]

Ah! I was searching using the wrong words.
Try googling for "polystyrene veneer".
Readily available and cheap!

However, all parties seem to recommend:
1) Polystyrene veneer
2) Strong lining paper on top
3) then paint or wallpaper to decorate

 

[BetterBetter]

Many thanks malshep!! I'm gonna take everything on board ans give it ago! wish me luck!

 

[Nige F]

Cheers guys for the replies.



I have been told that the reason why this is happening because its warm air from indoors hitting the cold wall ?

Exactly that. have you got extract fans in Kithen and bathroom

 

[EngineerDave]

Given that the condensation is a sign of warm air hitting a cold surface, which cools the air and condenses the water vapour, it is telling you that you are losing a serious amount of heat through those walls.

Polystyrene veneer may help reduce the condensation, but insulated plasterboard, with a vapour barrier, would be the best solution, as it would cut your heat loss through the solid wall. It will cost more, but as energy prices are only going to go up, it could be a good investment - better energy performance certificate if you come to sell the house, and less wasted heat / money while you live there.

Externally insulating the walls would be the best solution of all, as it would keep the thermal mass of the walls within the insulated envelope of the building, but would be very expensive and not really a DIY job.