arched leaded windows - draught and condensation issues

[damouse]

Hi all

We have 3 North facing arched windows in our house all with leaded detail. Two of these are on the ground floor and one is up on the first floor.

We always have issues with condensation during the winter months and I'm trying to do some work to reduce/remove this if possible this year. The condensation is pretty bad and we end up with pools of water each morning on the wooden frame.

I've tried the old silica gel in the window cill and that was ineffective.

I also have fitted a acrylic sheet cut to fit the arch on the inside of each window - with a gap of about 50mm between this and the glass but not sure if that is helping or making the problem worse. It seems to keep the cold out even though there are gaps around the edges so it's useful for this reason.

I'm not sure if there are leaks in the windows themselves (e.g. cases where putty has fallen out or cracks in the frame) - will have a look tomorrow if possible.

Any tips on what I could do to reduce/resolve the condensation issue?

Help appreciated!

 

[gregers]

1 little trick i have used in the past especially if the opening sash doesnt quite fit/close properly,is using some grease/vaseline ON 1 side and then using some clear silicone on the other side,then shut window and allow to dry.
this should take up any gaps.

 

[damouse]

Thanks Gregers

I unfortunately have no openers on these windows. They are fixed casements and to make things more complicated they are in my hallway/landing so ventilation is an issue as it's not feasible to leave the front doors open for a couple of hours a day ...

 

[gregers]

can you not install a basic secondary glazing then?

 

[dishman]

First you have to understand why condensation is forming on these windows. The windows are not the cause of the condensation, they just allow the water vapour in the air to condensate so you can see it.

Warm moist air will cool on the coldest surface in the house, which currently is your windows...but they are not the cause of the condensation.(water vapour)....you are.

If you secondary glaze your windows, it will make the window surface warmer. Water vapour may no longer condensate there, but you have not removed the problem and the water vapour may just condensate somewhere else....a wall prehaps...

The average family produces maybe 15 litres of water vapour per day if not more. To reduce condensation you have to look at the following.....

1. Ventilation, do you have enough? Does your bathroom and kitchen have extractor fans? Do you dry your clothes on Radiators? Do you have a tumble dryer? Do you have trickle vents on other windows, or open any of the windows in question a crack?

2. Central Heating controls: Do not let your house go from hot to cold to hot to cold. This is common heating use in houses with central heating as it is "convenient". This however exacerbates condensation, as warm air holds more water vapour than cold. Once air cools it will condensate. Try to keep a constant low background heat and turn it up when you need it hotter.