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Repairing condensation damage

Postby martymonster » Fri Mar 07, 2008 3:43 pm

Hi everyone,

I've found some useful tips on this site previously and haven't needed to post but I'm now at my wits end with condensation and the damage its causing and need some advice, please?

1. I've read other topics and the one thing I haven't seen is anything to do with properties that are heated via Economy 7. Perryman525 says to keep the temperature as constant as possible, which is easy (ish) to do with centrally heated properties, but I struggle to maintain adequate temperatures. Does anyone have any ideas?

2. My bedroom was beginning to suffer from black spores on certain parts of the ceiling and clothes within cupboards were needing regular trips to the dry cleaners. I noticed in the loft (as thankfully I have my own), that there was no insulation above these 'problem' areas. I took a trip to Wickes and got some loft insulation which I've duly fitted. Everything seems to be ok at the moment and the spores are not coming back. Would the cold surface of the ceiling have been the cause of this?

3. The main problem though is with my windows. The flat I purchased has secondary glazing and if I leave one side open, I'll awake to find every window in the flat ringing wet. If I shut them, occasionaly, I'll also find them wet. I've tried leaving the outer windows on the night latch and some times this works, others it doesn't. My window frames have started to (what I can only guess) soak up the water and have started to expand etc. The bedroom one is particularly bad and would (with slight pressure) lift of in your hand. If I replace these, would it be beneficial to get the brickwork treated at the same time? Does anyone know how I can get round the condensation on the windows?

Apologies for the long post, but this is really driving me nuts. Any help would be most appreciated! Cheers
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Simply Build It

Postby Perry525 » Sat Mar 08, 2008 12:41 pm

Marty, its nice to learn that someone has read on of my bloggs.
Lets see if I can help you.
The history of damp and condensation really goes back to the Clean air Act after the war, when the government stopped the burning of coal.
Up to then, the open fires ventilated our homes and there was no condensation and little damp.
In a few weeks (I hope) spring will arrive and with the outside temperatures warming, your problem will go away until winter returns.
Up to then, you can leave your windows open and because the outside air is dryer than inside (most of the time, not always) the water vapour in your home will gradually disperse to the outside.
If you want to stay warm?
You could stop breathing, washing etc;
Or, buy a de-humidifier and use it to dry your home.
Secondary glazing is good, for reducing noise.
If it is not sealed, fitted like sealed double glazing, water vapour will get inside.
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Postby cruque1 » Sat Mar 08, 2008 10:31 pm

Marty - undoubtedly a dehumidfier will help to reduce the symptoms but they are only really efficient in warm & relatively air tight rooms and can be costly to run! They don't really deal with the problem at source. To do this you need to improve background ventilation which can be done a number of ways - really depends how much you want to spend getting on top of the situation.
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Postby Perry525 » Sun Mar 09, 2008 2:02 pm

Marty, lets try again!
In para 1, heating is Economy 7, this indicates heating warms up overnight and gradually cools down during the day (unless you top it up=expensive)
In para 3, inner secondary glazing opened=condensation.
Outer windows open=sometimes this works.(Visible condensation doesn't form, some makes its way into the garden but, you are still breathing.)

cruque 1, writes, de-humidifiers only work in warm & relatively air tight rooms?
They don't deal with problem, cause.
You need to improve background ventilation.

Marty, I understand that you don't want the expense due to maintaining the rooms temperature 24/7 until Spring time.

Opening your secondary glazing=this does nothing to help.

Opening both the outer window and the secondary =this in most instances help reduce condensation-but, not always.

Where to start?
OK. cruque 1. De-humidifiers can only be judged to work if they collect water vapour from the air, walls, ceilings, bedding, clothes etc;
Put a de-humidifier in the middle of the Sahara, it will collect water from the air, people do this to have water to drink!
They do the job where ever they are!
They don't deal with the problem/cause.
They do! Condensation is caused by people breathing! Every time you breath out, your breath is laden with moisture!
You have on average 27 square metres of tissue in your lungs, every breath is saturated. Breath on a cold glass of beer from the fridge and see your breath condense on the glass!
Do you propose that we stop breathing?
You need to improve background ventilation.
Yes! You are correct!
However, increased ventilation = higher heating cost. (Don't open the window!)
And using a de-humidifier, solves the problem at little or no cost. It can save money. Why? Dry air costs less to heat than damp air!

OK so far?
At sea level at a temperature of 30 degrees Centigrade air holds 30 grams of water per cubic metre.
Drop the temperature to 20 degrees C and it can only hold 17 grams.
Drop it to zero C and it holds only 5 grams of water vapour.

This illustrates the importance of holding a constant temperature!
If the temperature drops the air cannot hold the same amount of water vapour and it starts to condense into your bedding (the bed feels cold) your clothes and everything in your home including the walls, floors, carpets everything!

Water vapour is a very fine gas, compared to air, its like comparing ball bearings with footballs.
It is so fine, there are very few things that are water vapour proof -certainly not plastic.

So, you cannot stop breathing but, you want to be warm! And you want to be warm at low or no cost.

A de-humidifier works the same as a fridge! It forms a cold plate. (And as it does it throws the warm dry air back in the room.)

Water vapour loves cold and it will travel through the air to condense on a cold surface.

Turn on your de-humidifier and the water vapour in the room, will wing its way to condense and turn into water - that you can empty down the sink.

I hope the above helps.
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