Heat, Mould & Condensation

trinity_p

Hi,
We live in a 2 bed end of terrace house and our windows upstairs always get covered in condensation as soon as summer leaves us, we wipe them down every morning and open them but the main issue is mould, it continuously grows along the ceiling on the window wall and is particulary bad in my 4 year old sons room. My son has asthma (well suspected) and has been hospitalised with croup a few times, now this may or may not be related to the mould but Im sure the spores cant be good for him.

We have tried sleeping with bedroom doors open and the bathroom window open slightly which is next to his room but this doesnt really make much difference, we really need to be able to close his bedroom door when we go to bed at night because we have cats and one in particular finds his bed appealing and ends up waking him.

I cant keep his window open all night because its just one big 1 metre square window with one of those cockspur handles and because in able to open it just a tiny bit (so he doesnt freeze when the weather is very cold) you cant lock it and therefore it doesnt feel safe.

We use all the radiators in the house except his because his bed is next to it but I wouldnt have thought this would be the cause as our room still gets mould and we use our radiator. Ive also stopped drying clothes on the radiators as Ive heard that causes humidity.

We have trickle vents in the kitchen window downstairs but none up, would it help if we drilled some in?

I read that leaving the heating on constant might help and I will try this altho I dont know how true this is and also am slightly worried about the cost.

Our house is fairly open plan, ie lounge onto stairs no hallway with door seperating so we cant just shut off areas we dry washng in and cook in (although I do open the kitchen window to let the steam out)

Can anyone help with this, we are at the end of our tether! We dont really have the room for a de-humidifier either.

Thanks

[Deleted User]

There are air filters around such as Bonaire etc which claim to filter mould spores and many other spores,which you can use until you get expert help in clearing the mould. Bonaire is one of the best, but expensive. Others are quite noisy to be kept on in a bedroom all night

rogerblack

There is one main reason for mould growth - damp.
This can either be from a leak, or from condensation.
Condensation occurs because you have warm moist air from inside the house hitting a cold surface.

http://www.ebay.co.uk/itm/Digital-Infrared-IR-Thermometer-Temperature-Laser-Gun-50-to-380-/320863922381?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item4ab4fae8cd

can be useful, as an example, to find out about cold differences easily - though simply placing the flat of your hand on the wall/ceiling and comparing it with walls in other rooms can be useful.

If the inside wall is cold, and air from the inside of the house is condensing on it, then it may be a defect in the insulation.
There is little you can do, other than to _drastically_ dry the air in the house or room.

A humidity meter of some sort - they are quite cheap - http://www.ebay.co.uk/itm/NEW-Digital-LCD-Temperature-and-Humidity-Meter-Thermometer-Clock-Alarm-Calendar-/140870928687?pt=UK_Kitchen_Accessories&hash=item20cc8fc92f
for example - will tell you about if the house is excessively humid.
Inadequate ventilation can cause this - but you really need to know in combination the temperature of the walls on which mould is occurring.

If the wall is not excessively cold, then there is no reason for it to be damper than other walls.
This leads to the other causes of dampness, water ingress.
Have you looked in detail at the roof?
Does it look in good condition?
Can you get into the attic?
Is there insulation all the way to the edges of the walls?

Sorry for a random and scrappy post.
I do not specifically recommend either of the ebay vendors mentioned, nor the products, simply as examples, I've not dealt with either.

Short-term-fixes - air filters have been mentioned - window catches to limit the opening of windows are readily available. 'cat gates' to allow an open door.
I would _not_ suggest a dehumidifier as a first step, without investigating if the wall is cold - if it is, then you need to get the room down to unhealthy humidities in order to stop condensation.

Condensation appearing on windows is entirely normal.

grahamc2003

You need to control the relative humidity, and the main way of doing that if you have a problem is with a dehumidifier and/or more heating. (Heating causes the relative humidity to drop, for the same amount of water in the air).

You can get dehumidifiers with filters which actually remove mould spores as well as other micro stuff (so the blurb says) - looks at Ebac for example, although I'd recommend a dessicant dehumidifier, which dehumidify down to zero degrees (the other type - compressor types - virtually can't dehumidify at all below about 13C).

The other thing to do is to minimise putting moisture into the air. Certainly drying washing on radiators puts lots of water into your room air (which, when the air cools on a cold surface, condenses out again as liquid water not only on your windows, but on everything else also at that temperature, possibly on walls in corners of the room). And water is what causes mould to grow - there's a certain relative humidity below which mould doesn't grow - you should measure your RH with a meter linked to above (a couple of quid off ebay).

When you have a bath or shower, isolate the room from the rest of the house and open a window. When finished keep the door closed and window open (or door closed with dehumidifier going) until the RH drops to about 60 if possible. Don't keep wet used towels in the house - get them outside on the line (anything drying in your house is putting water into the air). Don't leave water boiling on the hob without a lid on. Check no water ingress from anywhere like a leaky roof or guttering, or rising damp.

ariba10

Warm air holds moisture that reforms to water on a colder surface.

As mentioned a Dehumidifire would help dry the air.

trinity_p

Hi, Thanks so much for your responses, I thought I would wait until I had the roof checked out before I responded. And I have. They cant see anything obvious from the roof that would be causing the mould, no leaks. The insullation isnt too far out etc. I am having the fashia's replaced soon as they need doing anyway but this probably wont help. They recommended trickle vents upstairs and we were thinking of thes before so I think that is our next step and I am ordering some online today.
We do have two vents in the bathroom ceiling which go directly into the loft which we think is crazy, we have closed them and we still get the mould and condensation but the roofer said that we should block them off completely (which we will) and if the problem isnt resolved with the trickle vents alone then we will look at getting an additional vent in the bathroom with a pipe that takes the moisture directly out of the roof rather than straight into the loft. This is costly so we will do as a last resort.

Apon touching the wall and ceiling, they all feel about the same, none more cold than the other that doesnt get the mould?

I have ordered a humidy metre as advised and will let you know the reading. Any advice on when I should note the reading down, first thing in the morning and last at night?

I have taken your advise and also try to ventilate the kitchen when cooking,altho as I mentioned the house is very open planned. I dont dry things on radiators and all the washing goes on a rack to dry in my bedroom (its the only place we have room for it). I try and leave upstairs windows open all day long and this has all helped and some days we wake with no condensation at all (not many I hasten to add) but the mould is still coming back very quickly after cleaning it away and my house always feels colder because of the windows being open :-(

I really really dont want to leave my sons window (or mine) open during the night in cold weather...

WestonDave

Washing on a rack is no different to washing on radiators - either way you are drying it by evaporating the water into the air in the house. If you have problems with humidity it needs to be either dried outside, or in a tumble dryer, or in a shut off room (e.g. bathroom) with the window open.

You have the classic 21st century paradox - energy is expensive so you want to cut out draughts and keep the heat in, but by doing so you are also keeping in damaging levels of humidity. Insulation and double glazing has resolved the heat loss issue but at a cost of makes homes airtight and therefore often prone to damp. Picking a cold crisp day, and really venting the house through (with the heating off) and then heating it back up is a good way to seriously drop the humidity levels on an occasional basis if you haven't got a dehumidifier.

Not having the radiator on in your son's room is potentially part of the problem - chances are you are leaving the door open so you can hear him and also to allow heat from the rest of the house in to keep him warm. However what you are actually doing is letting the warm very humid air into a cold room - so its dumping loads of water on surfaces as condensation. That condensation is forming an ideal breeding ground for the mould.

Ideally you need a source of heat and/or a dehumidifier in his room. Perhaps putting a radiator cover cabinet over his radiator (you can buy them in kit form from most DIY sheds) would enable you to have the radiator on without it being a danger if he touched it. Even if you wedged a sheet of hardboard between it and the bed so that he is insulated from it whilst the heat can rise up and circulate in the room it would be a start.

Also once you have mould growing in emulsion paint it can be very difficult to get rid of it properly as it can feed on the paint and get into its structure. You need a proper mould cleaner such as HG Mould spray to get it cleaned properly - along obviously with resolving the heating problem.

grahamc2003

I dont dry things on radiators and all the washing goes on a rack to dry in my bedroom

If you dry your washing inside your home you're just putting litres of water into the air which is the opposite of what you want. (It doesn't matter whether it's on a radiator or not!).

The humidity will equalise throughout the house, so even if your bedroom doesn't have damp problems, drying washing in there will be a major contributary factor to condensation (and therefore mould) in any other rooms.

slipthru

I'm not really sure that getting trickle vents will solve the problem either to be honest and is a waste of money, I would buy a radiator cover as someone else suggested and turn your sons radiator back on, i would also suggest airing the house every morning or so for five minute to let fresh air in and help the damp air move outside.

grahamc2003

slipthru wrote: »

I'm not really sure that getting trickle vents will solve the problem either to be honest and is a waste of money, I would buy a radiator cover as someone else suggested and turn your sons radiator back on, i would also suggest airing the house every morning or so for five minute to let fresh air in and help the damp air move outside.

Trickle vents will help - whether they'll help enough is a different matter (probably not if washing is dried inside).

Air movement through the vents isn't necessary in order to lower the humidity - the water vapour will migrate out through the air and the vents if the RH is lower outside (and vice versa). It's do do with the partial pressure of the water vapour each side of the vent. Correctly designed, you shouldn't get drafts through the vent, and therefore shouldn't lose the warm air inside the house (a problem with regularly throwing open all the windows).

trinity_p

OK mixed views on trickle vents but as they are only a few pounds each I may as well go ahead and invest in some, will let you know how it goes.

Re the radiator being off, if I put it on will it really make much of a difference considering the heating isnt on constantly? I usually have it on for an hour in the morning then about 4 hours from 4pm ish, which now leads to the question should I have the heating on constant and the thermostat on a steady 19 degrees or something? If this will help then I will definitly get a radiator cover for my sons room!

I do have a tumble dryer but its part of the washing machine so its ok but not great and leaves clothes slightly damp and due to cost I dont ue it a huge amount, I was also advised that this puts moisture in the air too? Wha would be best considering this? The airer or the dryer then the airer to finish off?