major condensation issues double glazed windows

[hunggaur]

hi folks we are having major problems with condensation in all the bedrooms and the living room of our bungalow.

The bungalow was completely referbed about 18 months ago and all new windows and doors fitted. however we now have major problems with condensation.

they put a pay window in the lounge which did have a standard window before so the cill sits over the front wall and outside of the building.

we now have black mould appearing on the inside of all the window side returns.

now to the question how can we cure it i someone has mentioned to put in trickle vents. if so whats the best type and where do i get them from.

cheers

jon

 

[bhm1712]

It sounds like the windows are doing their job - the better insulated and energy efficient the more condense will form. Mould is a bi product of not managing the situation. Condensation needs to be wiped away every day otherwise mould will start growing quickly.

Best ways to reduce condensation as follows:

Use a cooker hood extractor fan when cooking.

Use a bathroom extractor when bathing and showering.

Dont dry clothes indoors or keep to a minimum and use a properly vented or condensing tumble dryer where possible.

Open the windows even just on the first latch/night vent latch for at least 20 minutes per day in all rooms. - might sound daft in winter but your house needs to breath. It doesnt really have a massive impact on room temp.

Dont keep too many house plants especially on window ledges.

These methods will help reduce the condensation problem although it will never fully disappear - we produce water in almost everything we do.

To clean the mould you can use something like cillit bang grime and slime and a good antibacterial cleaner. If embedded in the silicone sealer its time to refresh and keep on top of it in future

 

[crank39]

Take a read here....

http://www.thewindowman.co.uk/condensation.htm

 

[AronSearle]

You have cold bridging around the window likely due to the lack of any insulation, possibly they were poorly fitted, but likely it's just the way the building is as most UK stock buildings are pretty rubbish in terms of insulation.


You will have to leave windows open a fair bit to remove excess moisture relative to the cold surfaces, or leave an extractor on for reasonably long periods.

You could re-fit the windows or possibly open up the reveals and install foam insulation to deal with the cold bridge, but that's a lot more work and it's likely your building is to poorly insulated overall to make a big difference.

 

[masona]

they put a pay window in the lounge which did have a standard window before so the cill sits over the front wall and outside of the building.

So does the new bay window cill sits over the front wall?

 

[masona]

You could re-fit the windows or possibly open up the reveals and install foam insulation to deal with the cold bridge, but that's a lot more work and it's likely your building is to poorly insulated overall to make a big difference.

The problem is when improving insulation elsewhere, the air-moisture is still trapped in the room, as you says the only way is more ventilation

 

[AronSearle]

Nothing personal but I do hate that attitude.

Do you think nordic countries spend winter with the windows open?




Sure you need to manage moisture levels, but if you have cold surfaces (<12/14c), then you will almost certainly get condensation on those surfaces, unless you open windows excessively or run a dehumidifier 24/7 (and then it can still happen).

From what the OP describes, there are insulation gaps in the window frame, or around the frame either due to poor fitting or poor quality windows. With the fitting it may be that they didn't insulate around the frame, didn't set it in line with the insulation, or the wall simply doesn't allow for enough insulation. Not knowing the date of the building I couldn't guess how likely the latter is.

 

[crank39]

From what the OP describes, there are insulation gaps in the window frame, or around the frame either due to poor fitting or poor quality windows.

And where has the OP described that then, i'll be damned if i can find it?

 

[AronSearle]

In the OP's first post.

we now have black mould appearing on the inside of all the window side returns.

It may be when they fitted the frame, the frame was smaller than the opening by the typical <1inch, and they have packed this to level the window, but not filled this void with expanding foam, leaving a direct cold bridge.

Only a guess, but it's a very common mistake and leads to cold spots around the window side returns causing condensation to form very easily.

It could also be cold bridging around the window through the wall either by the position the window has been installed relative to the wall insulation (or the wall has no insulation), again leading to cold edges around the window.



Certainly moisture levels have to be managed, I don't disagree with that, but far to many windows are installed poorly (or are poor quality, or the building is poor quality), so you end up having to open windows far more than you need to, decreasing heating comfort levels and wasting energy.

 

[masona]

Do you think nordic countries spend winter with the windows open?

Some of them do as most of them have log burner and the very common are the mechanical air ventilation which is widely used