Condensation

[Hugh Jaleak]

Construction as far as I can tell, is brick/block walls to both sides and rear, front is somewhat different. From ground to sill of ground floor windows is brick to match rest. From there on up, between and above the windows to next floor is rendered, this continues all the way to eaves level, on both end blocks.

Double glazing seems to be the later generation, internally beaded etc. The Council undertook a programme of upgrading their housing stock in the late 90's/early part of the 00's, before flogging the lot to the HA for £1!!!!

Just to confuse the issue even more, the two 'middle' blocks don't have the rendered area as described, instead this is covered with wooden cladding. As mentioned previously though, there is a noticeable temperature difference on the internal walls of the flat, the side (brick) wall being considerably warmer to the touch then the front (rendered) wall.

 

[noseall]

I have observed this problem before.

 

[Hugh Jaleak]

Is there any explanation for this though Noseall?

 

[dishman]

The bottom flat may be more susceptible to condensation because they are on the ground floor (usually a cold concrete floor) so no heat or ventilation from below. The ceiling to the next flat is again (usually) concrete, which means less chance of ventilation or air escaping/moving, trapping more moist air in the flat.

So it may be that often the lower flat can have a lower ambient temperature than the other flats. This means it will possibly cool quicker or experience a quicker temperature change when the heating goes off. This will encourage more condensation to form, quicker, and maybe therefore more prevalent in the bottom flat.

This seems to be more prevalent in social housing/student housing as (this is just anecdotal observation) people seem to be more conscious of heating costs(although most people are these days). Therefore heating is used in a way that also encourages condensation to form. It is on for short burts when the occupier feels cold (or on twice a day only). The on, off, on, off heating and cooling encourages condensation to form. Heating should be on a low temperature all the time and turned up when it feels really cold. As mentioned, ventilation is just as important.

Again people assume, close windows, keeping heat in will stop condensation (sounds logical) but this just again encourages and exacerbates it. Keep windows open or on night vent, trickle vents open, extractors working and on....and so on.... Add to this poor placement of heaters/radiators and no air circulation means uneven heat distribution and cold areas/spots form, and condensation forms in these areas (this is why air circulation and good constant/ambient heat/temperature is so important)

As a point of reference, I have large single glazed timber framed windows, (leaded lights) in a house which creates a lot of moisture on a daily basis. I have the condensation controlled, and only get it when expected, or intentionally do something to create a lot.

 

[Hugh Jaleak]

Interesting, thankyou. I can see your point, but it still seems historically that this particular flat has always had a much worse condensation issue than the other 3 on the ground floor in that block....

Also good point re radiator placement. Central heating was retrofitted to a lot of the (now) HA places 10-15 years ago. With these flats pipe routing was never going to be easy, (no ceiling void and a concrete floor), so pipes are surface mounted just above skirting around the flat.

Rad placement seems odd, (usual placement is under windows although this is subject to a 'heated' debate in the plumbing forum!), but although in several rooms the pipes and going around 3 sides of the room to get to next room, rad is just inside the door yet pipes pass it, round the room and under the window to next room.... Rad were probably sized to room, but 'standard squareish' rad is no doubt cheaper than a longer, lower, rad that would fit under the window....

 

[dishman]

If I were you, I would:

1: Follow the all advice on here about heating and ventilation. Take it as far as is possible to find how much ventilation is required. It may be odd and inefficient having windows open while heating but that is the compromise to reduce condensation.

This is a rough/conservative guide on average as to how much moisture is released in a home on a daily basis:

2 people at home during the day: 3 pints (just breathing)
A bath or shower: 2 pints
washing dishes: 2 pints
Cooking/kettle: 6 pints

Total 13 pints or just over 7 litres. The smaller the property the more this is concentrated into a smaller area...

2: Check to see if cavity wall insulation has been installed on all elevations, if not get on to housing association, mention the decent homes standard.

3. Although this may be unlikely....as a further check get a drain company out to see if there are still problems with the leaky drain you heard rumors about. They will be able to send a telescopic camera down it to check for leaks.

 

[Hugh Jaleak]

I think there's 7 litres on the windows/in the windowsills, never mind anywhere else! I've told her to ventilate, now moaning she cant keep the flat warm (with a 3 week old baby I appreciate she has to keep it fairly warm in there), but I will monitor the situation.

Have asked for a meeting with Housing Officer to discuss situation, still waiting on her to come back with a date/time. I've plenty of experience with drainage, going to lift the covers next time I go round and check which way the drains run, really cant see them going under the building, but you never know......

Once again, many thanks for your input.

 

[dishman]

Just another quite insightful document for you and others to look over.

http://www.1stassociated.co.uk/condensation-cold-bridging.asp


Other documents posted previously

http://www.bolton.gov.uk/sites/DocumentCentre/Documents/Condensation and Mould.pdf

http://www.scotland.gov.uk/Publications/2005/05/10103020/30224