Mould behind bed in bedroom...

[Howie]

Well, I am having some damp / mould problems since buying this modern house! Wish I'd not moved out of my 1820's built one!

Anyway, It's a 1970's build which is all double-glazed. On 3 floors. The bedroom wll I am concerned about is an outside-facing, solid concrete-block wall and is cold to the touch. We have our bed against it. I can't put the bed anywhere else.

In only 6 weeks since we moved in, we have today discovered black mould spots on the pillows, sheet and wall behind the bed.

There is oil-fired CH in the house, - but we don't like heat in the bedroom really. I was wondering if anyone has any suggestions about stopping this problem without freezing ourselves every day by pulling out the bed and opening all the windows ! ?

TIA (I hope)

Howard.

[Christian McArdle]

If you are willing to do a bit of work, I'd suggest sheets of celotex (50mm good, but 25mm will do at a pinch) covered in foil backed plasterboard on the outside wall. You may also need to add some trickle ventilation, particularly if it is older double glazing with no integral trickle vents.

The insulation will substantially raise the temperature of the wall surface, preventing condensation. The ventilation will ensure that any moisture laden air is expelled.

Christian.

[BillR]

If it is indeed a solid concrete wall without a cavity you will continue to get problems unless you have considerable quantities of dry heat and ventilation. Solid concrete walls are ok for carparks but not for homes. I had such a property many years ago, even when it was new the problems occurred. The developer even stripped off all the plaster in the affected wall and replaced it with a layer of polystyrene based insulation underneath, which did not cure the problem.

[Howie]

|> In only 6 weeks since we moved in, we have today discovered black |> mould spots on the pillows, sheet and wall behind the bed. | |If you are willing to do a bit of work, I'd suggest sheets of celotex (50mm |good, but 25mm will do at a pinch) covered in foil backed plasterboard on |the outside wall. You may also need to add some trickle ventilation, |particularly if it is older double glazing with no integral trickle vents. | |The insulation will substantially raise the temperature of the wall surface, |preventing condensation. The ventilation will ensure that any moisture laden |air is expelled. | |Christian. | Well, I appreciate your suggestion, and - I don't mind doing a bit of work. But this outside wall is rather a large surface area. The house is build on a granite hillside and the wall is the side wall which is 3 stories at the front and 1 story at the back (full depth of the house). Under those circumstances, I would rather not do anything to the outside wall if possible.

H.

[David Hearn]

I think he meant to put the celotex on the inside of the outside wall, not on the outside of the outside wall. ;)

D

[Christian McArdle]

Although fitted on the outside wall, you attach the celotex to the inside of it, in the rooms that have problems. It also means you can do one room at a time. No need to do it all in one hit. I'd suggest doing the master bedroom first and seeing what a difference it makes first. It will be substantial, both in comfort and condensation. Much of a human's perception of warmth comes from radiation, not air temperature. Having warm walls helps enormously with this. It is also why an open fire in a cold room can be more comfortable than a warm room with cold walls.

It will also have the side effect of saving you a FORTUNE in heating bills. By insulating your roof and all your walls properly, you could reduce your heating bills to third or a half of their present value. (Even more in some cases).

Christian.

[RichardS]

My wife used to have this problem when she was in her flat - similar construction from the sounds of it.

A small bog standard argos dehumidifier sorted everything out.

cheers Richard

-- Richard Sampson

email me at richard at olifant d-ot co do-t uk

[Thomas Prufer]

If you don't like heat in the bedroom, you must ventilate it, and keep the door closed during the day. Else moisture will move from the rest of the house to that wall: warm air will go in, cool against the wall, the moisture will condense, and the cooled air will circulate, out again. A wall damp for part of the day (somewhere it says 3 hours of damp a day are enough) will grow things...

Perhaps heating the bedroom during the day?

Thomas Prufer

[Howie]

|On Tue, 02 Dec 2003 10:56:46 +0000, Howie | wrote: | |>There is oil-fired CH in the house, - but we don't like heat in |>the bedroom really. | |If you don't like heat in the bedroom, you must ventilate it, and keep |the door closed during the day. Else moisture will move from the rest |of the house to that wall: warm air will go in, cool against the wall, |the moisture will condense, and the cooled air will circulate, out |again. A wall damp for part of the day (somewhere it says 3 hours of |damp a day are enough) will grow things... | |Perhaps heating the bedroom during the day? | |Thomas Prufer

This all sounds quite common-sense. Thanks for the reality check! I suppose I feel quite strange adding ventilation to a house which is effectively draughtproof. But I can certainly see that this is likely to be the main part of the problem. As a related issue, at this time of year where the air (especially on the s.devon coast), is damp during day and night, is ventilation as effective?

H.

[Christian McArdle]

Provided the outside temperature is lower than the inside, outside air will always have some spare humidity capacity that could be used. However, if the outside air is 100% saturated AND close to the inside air temperature, that spare capacity might not be very much.

Remember that hot air can absorb much more water than warm air. This is the main reason why heating reduces condensation. Even fully saturated damp cold outside air doesn't have much water in it relatively speaking when heated to inside air temperatures. However, you DO have to heat it a little for this effect to happen.

Christian.

[Mary Fisher]

This is an interesting observation. I've noticed that many modern houses make it difficult to place furniture because so often there's at least one 'feature' (window, door, fireplace ) on each wall in a room. Sometimes the door/s is/are halfway along the wall. Since the rooms are quite small to start with the arrangement of furniture is very limited.

Why do architects do it? Do they live in houses like that? I think not.

Mary

[The Natural Philosopher]

All you need to do really is the old German Hausfrau trick of opening all the windows in the morning after getting up, to air the place, and shut em before the heating cuts in in the afternoon.

Its typical of what heppens in places that are double glazed with no other insulation - no ventilation, as DG seals down hard, build up of RH and condensatuon on cold walls that are uninsulated.

Dry lining the wall with a vapour barrier over insulation is the correct solution, as is adding some trickle ventilation - or even leaving the window open a crack and running a little heat in the room.

Full treatment would be to cavity fill with insulation, and add trickle vents.

[The Natural Philosopher]

Today I am utterly in agreement with you. Must be the moon. :-)

[The Natural Philosopher]

Yes. Your room is warmer than outside so the condensation implies the internal air is carrying more water than the external. The trick is to bring in sopoping wet, but cold, outside air, warm it so it can absorb more moisture, and then get it out again where it can form fog etc :-)

To this end, trickle vents on opposite sides of the room to take advantage of wind etc, plus a little bit of heating - may be no more than seeps through the walls floors and ceilings etc - will do teh trick.

Then by raising teh wall temp - insulation - plus a vapour barrrier to make sure o wet air gets to teh cold bits - will stop the localised dampness.

It sounds a nice house - granite, slope, devon? Exmoor? Dartmoor? Lovely. Well worth going the whole hog and dry lining with celotex and plasterboard IMHO. It will make a HUGE difference to how cosy it feels. # I had an old fen cottage I rented on teh cambridge fens,single brick, got double galzed, same probs especially in teh kitchem I used cork tiles and it transformed it - just 1/" of cork made a tremendous difference. That's how cold it was! if you can put on 2" of celotex, you will not believe it afterwards. But you MUST add some vents.

It is crazy, but modern regs require you to build an airproof and heatproof box, and then punch specific holes in it so you don't suffocate :-)

[The Natural Philosopher]

The classic case of that, was in my kitchen two summers ago, when even with an aga running, and inside temps in the 35 region, the incoming cold water pipe was dripping from condensation...

[Thomas Prufer]

One quick fix for now: move the bed away from the wall, six inches, less will do if more isn't possible. This will allow more air behind the bed, and the wall will be a bit warmer. Otherwise, it's a cold pocket... Also check behind any other furniture, pictures, curtains against that wall.

Then, add some local heating: say a 60 watt lightbulb on during the day, between the bed and wall. I'd want to dry that spot aggressively, and kill the mold before it spreads deeper: first, fight the damp, second, kill-with-chemicals -- alcohol, white vinegar, or bleach will all do.

Thomas Prufer

[Peter Taylor]

Howie - insulation/ventilation is the best answer, but it's a biggish job and maybe a bit late to start it for this winter. If you want a KWIK-FIX solution, providing a warm surface e.g. using cork will stop the mould forming, but any vapour getting through to the cold surface will condense so make sure the warm surface is sealed properly. Any oil paint or varnish will do. I don't like heating bedrooms either, but some heat really is necessary - have you thought about fitting a Thermostatic Rad Valve? Or maybe a 500W tubular electric greenhouse-type heater might help.

Also consider ways of minimising the amount of vapour you produce. The obvious problems are drying clothes indoors (esp on radiators), non-ducted outlets from tumble driers and cooker hoods, using gas or paraffin heaters (freestanding ones without flues) and keeping the window closed when/after you have a shower. Gas cookers make tons of vapour just from burning the gas, as well as steam from things on the hob. Is there a fan in the bathroom or the kitchen, and is it working OK? Maybe a humidistat fan controller might help. A dehumidifier would certainly make a difference, but they use a fair bit of power.

Hope this helps Peter

[Howie]

|The Natural Philosopher wrote: | |> All you need to do really is the old German Hausfrau trick of opening |> all the windows in the morning after getting up, to air the place, and |> shut em before the heating cuts in in the afternoon. |>

|> Its typical of what heppens in places that are double glazed with no |> other insulation - no ventilation, as DG seals down hard, build up of RH |> and condensatuon on cold walls that are uninsulated. |>

|> Dry lining the wall with a vapour barrier over insulation is the correct |> solution, as is adding some trickle ventilation - or even leaving the |> window open a crack and running a little heat in the room. |>

|> Full treatment would be to cavity fill with insulation, and add trickle |> vents. | |Howie - insulation/ventilation is the best answer, but it's a biggish job and |maybe a bit late to start it for this winter. If you want a KWIK-FIX solution, |providing a warm surface e.g. using cork will stop the mould forming, but any |vapour getting through to the cold surface will condense so make sure the warm |surface is sealed properly. Any oil paint or varnish will do. I don't like |heating bedrooms either, but some heat really is necessary - have you thought |about fitting a Thermostatic Rad Valve? Or maybe a 500W tubular electric |greenhouse-type heater might help.

Ah. I like the greenhouse-heater idea. We have one of those beds with a base made of 2 sections, wooden frame covered in fabric. I could stick a heater in there and it will heat the bed (a bit), whilst radiating warm air away from it all around (including next to the problematic outside wall. Would this work I wonder?

|Also consider ways of minimising the amount of vapour you produce. The obvious |problems are drying clothes indoors (esp on radiators), non-ducted outlets from |tumble driers and cooker hoods, using gas or paraffin heaters (freestanding ones |without flues) and keeping the window closed when/after you have a shower. Gas |cookers make tons of vapour just from burning the gas, as well as steam from |things on the hob. Is there a fan in the bathroom or the kitchen, and is it |working OK? Maybe a humidistat fan controller might help. A dehumidifier would |certainly make a difference, but they use a fair bit of power.

All good points. Thanks. I have a dehumidifier - but I don't want to run it in the bedroom. I might be able to find a place for it on the landing though. I WAS going to sell the damn thing! | |Hope this helps |Peter

Certainly does. Cheers.

[Scott M]

Got a whole house like that. The lounge has a staircase as one wall; the hall door, window and radiator as another. There's a fireplace on the long wall opposite the stairs and the kitchen door in the remaining wall. The two chairs of the three piece suite look as if they're waiting for someone to collect them...

Then we have the kitchen where they only allow you two standard sized appliances, ie a fridge & a washing machine. There's no allowance for a fridge-freezer unless you cut out the worktop over the fridge, so you end up putting the FF in the dining room end of the room (yay) unless you want to have a separate freezer in the garage. But you wouldn't be able to get at it as the ba****s from Ba****s couldn't be bothered to put a backdoor into the garage so it's a 50 yard dash out the front door if you do.

And don't get me started on the main bedroom - there's pretty well only one way round the furniture'll go! Or the 3rd so-called bedroom where I can reach both walls at the same time...

Moving soon.

[Brian S Gray]

One thing that might help a little when you try the earlier suggestions is to make sure that there is room for air to circulate between the bedhead and the wall - I have used cotton reels fastened to a headboard to provide some space in the past. Trickle vents in the windows and some heat sound the essentials. Incidentally, from your description, I am not clear what is on the outside of the wall at this point - is the house on, or in, the hillside?