Condensation problem

Warm air, cold surface = condensation.

Dehumidifier will help when switched on but not a cure for the problem. One needs ventilation but also the air needs to be 'moving'.

Make sure no gaps in attic where the insulation is directly above the ceiling. Yes, sofit vents need to be clear.

Do you keep the windows slightly open?

 

As Kools says - you need to vent out that damp air to stop it condensing.

Many peeps equate 'cold' with 'damp', but it ain't necessarily so. You can prove this to yourself in 24 hrs - tonight, if it's cold and you know you would get condensation, leave both windows cracked open. You might have a chilly draught, you might have to make a dash for the warm bed, but you should wake up to a dry room.

In the evenings, when your heating is on, the moisture levels in this warm air builds up. It comes from you, your washing, your bathing, your showering, etc.

Overnight, when the heating it turned down or offski, the air temp drops and it can no longer hold that moisture in it - it will therefore condense out on the coldest surfaces it can find - and that bedroom window and ceiling are two of these places.

Solutions? Keep the bedroom door closed all evening to reduce the warm air getting in there, and also keep both windows on 'vent' setting all evening. That will help give it a good start for the night.

If you find that too chilly, and that's understandable, then at least keep the door shut and allow the radiator to warm up the room before bedtime. However, as soon as you go to bed and the heating is turned down, you will end up with condensation unless you vent it out - and that means both windows on vent. Can you try this, or is there too much traffic noise outside?

Ok, you know where the coldest spots in that room are - that window and the ceiling above it. The window is obvious - they are the coldest surfaces. Perhaps an upgrade in quality will help? Or adding secondary glazing almost certainly will - but both options will cost. Other than that, it's 'vent'.

That ceiling is cold there 'cos it's nearest the soffits where cold air is flowing over it. However, you MUSTN'T block these soffit vents or you will risk having a similar condensation problem up in your roof space, and that could cause rot over time. So, instead, you need to add extra insulation to that ceiling.

I'm guessing you do have loft insulation already up there? If not, that's probably your answer! But if you do, you need to look at boosting it in that cold area without blocking the actual ventilation up there.

Not sure what the best solution is (well, I do - it's to add a layer of insulated plasterboard to the actual ceiling below, but that will take work). For a quick and cheap improvement, perhaps removing the 'wool' loft insulation you currently have up there away from the first metre nearest the eaves and then cutting a high quality insulation sheet such as Celotex or Kingspan and fitting it tightly down between the ceiling joists and against the p'board upper surface? If you use, say, 2" stuff it should, I thin, make a noticeable difference. Then roll the 'wool' stuff back over this, but stopping short of where it might block the eaves venting - taper or bevel the wool layer down as it goes in to the eaves to make SURE it ain't blocked.

The best solution to your ceiling is to line it on the bedroom side with insulated plasterboard - the thinnest 35mm thick stuff will do. This is simply attached using longer p'board screws and it will then need a skim of plaster to finish it. Your call as the whether it's worth it.

One thing to check - make 100% sure that the mould on your ceiling is being caused by condensation from the room (ie it's only on the surface) and not by condensation (or a leak!) dripping on to it from the loft side.

Anyhoo, to prove to yourself a point, if you can try leaving both windows cracked open one cold night... Wake up to a cold - but dry - room!

 

He said the windows are new so should be fine

 

Ah...

All I can suggest is that you throw on an extra duvet... By all means have the heating on and the windows shut in your room until bed time - but then crack them open and jump into bed...

During the night your bod gives out summat like a pint or more of water? So 2 pints in your case. That water has to go somewhere - either out the window or else running down your window.

(And there's the moisture already in that warm air - ready to come out as soon as the temp drops.)

Best procedure, I think, is - leave your bedroom cool in the evenings and with door shut but windows cracked open. It'll then be cool but dry. Then send yourself or summat up then an hour before bedtime and close the windows and turn on the rads (you know you can get timed TRVs - so automatic?!).

Get ready for bed - get your partner in there first nice and cosy...

Shut off the rad and crack open the windows.

You won't be cold during the night - 'cos you are in bed with a cosy person.

Morning scenario - jump out of bed before your partner, slam shut the windows (I mean, close them quietly...) and turn on the rads.

Happy days

 

Yes, rads and heaters will help. But do bear in mind what these will actually do - and that's warm up these surfaces so that they are no longer the coldest in the room! It won't get rid of the moisture, so it'll try and condense out on the next coldest surfaces instead.

You might then find damp on walls in places like behind units, wardrobes, etc., or in corners, low down the walls.

If you can't leave both windows open, could you crack open one and also leave the bedroom door open? Perhaps that through-draught might help.

 

Ooh - I like that!

So, you coat the occupants of the house with damp-proofing compound so their sweat no longer comes out and causes condensation?

Nice.

Now, go back down under from whence you came.

 

Yeah, insulate walls/ceiling as best you can, maybe think about putting another rad under the window. I wouldn't be in a rush to shut your windows in the morning, I'd do the opposite and open the windows wide when your out of bed and dressed, and let the room air for a while - it doesn't matter how cold the room is when you're not in there. Don't overheat the room, hot air holds more moisture and the walls and ceiling will still be cold if your insulation is poor.

 

Extra heat in the room will just drive the moisture into the air as hot air will hold more moisture. The cause of the damp is occurring within the building structure (interstcial condensation). As the moisture moves through the brick from the warm side to the cold, at some point the moisture will condense in the brick. In time the brick will become wet and the mould will grow on the internal face. Your best solutions are, 1 fit a cooker hood that extracts to outside. 2, stop drying clothes on the radiators. 3 Fit an extractor over the shower. 4 get a dehumidifier and use it every day when the windows aren't open. 5 Dry line the room with battens and plasterboard with insulation behind and a vapour barrier. 6 Throw out the old vented tumble dryer and buy a condensing one, or better still a heat pump type, these are very cheap to run but will cost £600. Hope this helps.

 

We have a bathroom with no window. It's in the centre of the house and we get condensation but it's very little and all gone in around 10mins. Open window or close window makes no difference. The answer is to insulate walls and ceiling. All I here is open window. Get a vent. Fit an extractor. Won't do a thing to stop the problem. Insulation will though but not easy to do. Products like Swish Marbrex works well though .

 

Think you posted this before Wayners on another thread.

 

Probably. Drives me mad though. Folks saying open window or fit a vent. Family members really get on to each other about it. Not the answer though. All to do with due point. Due point calculation ect. Right old read that. I won't post again on subject.

 

One cause of condensation on walls that is often missed is irregular heating of the building. If the heating is only switched on a certain times (eg no heat all day because at work) and the building fabric i.e. walls, ceilings and floors, along with all the furniture, cools down. When the heating is then switched on, all the cool surfaces can suffer from condensation. Bearing in mind it can take several hours for a buildings fabric to warm up to air ambient when heating is switched on, this can lead to severe condensation problems. By the time the fabric/furniture reached ambient it is often time for the heating to go off again i.e. bedtime and the whole cycle starts again. This is no only costly in energy terms but uncomfortable as well. Unfortunately the only solution is good insulation and try and not let the building cool down too much in between heating cycles. Of course if the house is empty for a long time each day this is not always economical although there is a plus point in that where the fabric/furniture is maintained at a reasonable temperature, the actual room temperature when the building is occupied can be less whilst still being comfortable. There is little that is more uncomfortable than warm air and cold furniture.

Phil

 

It is because some one is breathing, we exhale moisture and also sweat, I had a room with problems, when stopped using as bedroom and it became a store room no more problems. The original windows were single glassed and steel framed there was a tray built into the frame and holes to outside, so water condensed onto the window, ran down the window, then was drained to outside.

When double glassed units are fitted they can't remove the moisture any more, fit an extractor fan and you have just got rid of the whole idea of double glassing and keeping heat in, so only real option is a heat recovery unit.

We are living people so we produce moisture some how it has to be removed, be it an AC or a de-humidifier, open window, extractor fan, or heat recovery unit, we have to do something to remove the moisture. I liked the single glassed window, it removed moisture without causing a draft, however didn't look that good.

 

Ya I used to have the same problem as well. I remember back then I had to wipe the window all the time...