Condensation on walls - please help!

[Basketofchocolate]

Our bedroom has a large bay window that faces north.
We moved into the house last year and found that around this time, we had a condensation problem with the wall under the window. We sought advice and tried a couple of things, but thought it was mainly due to a radiator under the window that was badly placed across an angle. Also, the survey mentioned that it was a single brick wall just there.

So, over the summer just gone we sealed the bricks on the outside (pebbledash) and then painted three coats of anti-condensation paint (after stripping all paint off inside walls), a top coat of emulsion and removing the radiator.

We don't have the small radiator on in the bedroom (on opposite wall to window) and usually have the small window open.

However, last week, when it turned cold, we suddenly had a wet wall again. Really wet :( Paint bubbling up and now there's even some mould on the nets :( Am really depressed by it and we really don't know what to do next.

Self-confessed DIY ingenues and no spare cash really.....can you help?

Any suggestions that we can do for this winter? And anything we can do when the wall dries out again?

We've started making sure we dry the windows each day and have put a small de-humidifier by the wall - has taken in some water but wall still wet.

Sorry this is so long.

[Basketofchocolate]

Anybody??

[OliviaBenson]

I'm sorry to say but sealing the brick work can make a problem worse. Do you dry washing indoors? You need to ventilate as much as possible. Is there any pipe work near the wall, could that have split and be causing the problem?

[Basketofchocolate]

No, no pipes.
We do dry washing indoors - no alternative - but not in that room, usually use a room downstairs for that

[wonkylegs]

Agree pebbledashing the exterior probably has made it worse.
Condensation needs both heat & ventilation to improve. With ventilation being the key ingredient that most people can't get right.
You need to tackle it 2 ways.
Reduce the amount of moisture in the air in your house - make sure you use extractor fans, dry washing outside or in TD or in a room with vent or open window, use dehumidifiers.
Then you also need to sort out the ventilation and air circulation in your house.
Do your windows have trickle vents? If so make sure they are open/clean. If not consider fitting them.
Make sure there isn't any furniture up against badly affected walls.
Make sure you have adequate extracts in bathrooms & kitchens AND that they are used.
Easiest thing is to actually air your house everyday by opening windows although I understand that this is less desirable when it's cold outside.

[Basketofchocolate]

Wonky = we didn't pebbledash, that was there already.

No room/cash for a tumble dryer and nowhere to dry with a window open. An airer next to the radiator (hardly on) is not drying washing in 3 days at the moment.

No trickle vents on windows - are they the small vents in double glazing? Sadly these ones don't have those. Windows are open or closed only. Can only be open when someone at home, so makes it tricky...and cold! I do try and air the rooms, but then the heating comes on as it is colder, so then we are paying for the heating to go out the window.

No furniture up against the wall.

[Rowlers]

What everyone else has said.
What kind of houe is it?
Is it yours?
It's quite unusual to have single brick walls in main house - OK for a garage but in house - no!! Pebbledash and sealing it will do nothing to ease the problem.
You can get exterior and interior insulation for walls but I suspect it will be relatively costly.

[Basketofchocolate]

it's our house and was built in 1930.

[mrsminiverscharlady]

I would imagine that the biggest issue is that the wall is single brick and that it is cold and any moisture in the air condenses there. I would get a builder in to see about putting internal insulation on the single brick parts which will make the wall less cold and reduce the amount of moisture condensing there. In the meantime I would try and get into the habit of wiping down the wall every morning.

[schmalex]

My bedroom in my parents' old house had this problem. It was also 1930s with a single brick wall under the bay window. I think my dad cleaned it off and then bought some internal insulation panels from B&Q and that solved the problem? I am not very handy though, so I'm not quite sure how it's done!

[wonkylegs]

Trickle vents go in the frame here
You can add them to existing windows to improve ventilation

[mousmous]

if washing takes 3 days to dry your house is very humid.
maybe you can get a dehumidifier to help?

you need to ventilate more effectively. that doesn't neccessarily mean leavingthe window openall the time, you can also open all windows as far as they go for a few minutes a few times a day. heat in between.

(simple physiscs: warm air can hold more moisture than cold air, so by heating up the room the moisture is drawn out of the furnishings/walls/laundry. opening the windows exchanges this warm humid air with colder dryer air from outside-even if it is raining).

wrt wall, you need a damp specialist, I think it would be difficult to get a good solution with diy.

[vj32]

Open windows, and take ALL your washing to the laundrette if you can't get it dry outside. We had this problem in our last house. We also used dehumidifiers - the chemical water catcher things not electric ones. It all helped, but didn't cure the problem.

[HelnBack]

We had the same problem in a 1930s house and have improved things by not drying any washing in the house, using a special insulating wallpaper on the affected walls (found on the internet) and anti mould paint/wallpaper paste.

We also keep furniture away from the problem areas and try not to let any of these rooms get too cold.

[PigletJohn]

have you got an extractor fan in your bathroom? Does it work?

[Basketofchocolate]

HelnBack - THought idea was to keep the room cold so same temp as outside?

Piglet - nope. People who put DG windows in had no forethought/money

[PigletJohn]

dry the wall with a cloth, and tape a piece of clear plastic tightly to it. See if water forms on the wall side or the room side and report back.

Does the wetness coincide with rainy weather?

If you drape wet washing around your home, without ventilation, then your home will suffer condensation, damp and mould. Also if you have baths and showers without ventination.

Before and during airing the house, turn the heating thermostat down. A good time is in the morning while the beds are airing. They get warm and moist at night.

[Basketofchocolate]

PigletJohn - DH is intrigued by the plastic thing. Will clingfilm work?

[PigletJohn]

yes

tape the edges

[steppemum]

If you have damp air anywhere in the house, it basically spread through the house and then condenses on the coldest spot, wherever that it. In your case it is your bedroom wall.

You need ventilation. Which doesn't help if it is raining a lot outside.

There have been a lot of threads about condensation, I would google some of the them for ideas. Drying washing is probably the issue. Do you have extractor fans? In the bathroom and kitchen?

[Basketofchocolate]

Will try the cling film.

This morning the wall was dry. Had the window open as usual overnight but I guess wasn't as cold as was cloudy and rainy over night.

Sunday was clear and sunny all day so I guess was colder over night which led to a soaking wall on Monday?

Will the drying washing help if I keep the bedroom door closed of that room? And keep the washing downstairs? There's more ventilation downstairs due to front door being opened and more draughty downstairs.

[PigletJohn]

if you do drape wet washing inside the house, spread it thinly and open the window, but not the door. use the side of the house where wind blows out of the window, not inwards. Turn the radiator off in that room. Airflow dries water, not heat.

Look into getting an extractor fan fitted, in the bathroom certainly, but preferably also the kitchen, preferably an extractor hood. A core drill from a tool hire shop will make a neat round hole in a brick wall. It is rather heavy, noisy and dusty.