other condensation problem Post questions and find answers on glazing, double glazing, upvc glazing, conservatory glazing, fixtures and fittings etc....

[hamco]

I have double glazing throughout and have looked at the posts, but I can't see one which relates to the problem I have which is, I have quite bad condensation not between my double glazing units, but on the inside.
In winter or even cold summer mornings it is quite bad and all the windows have to be wiped down with a cloth. Is there anything I can do about this ,as I thought you didn't have condensation with double glazing?

[stoneyboy]

hamco,
Depends how wide the gap is and how airtight you keep your home.
If you never open the windows in winter ventilation may be the problem.
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[hamco]

thanks, Our house is so cold in winter, we can't open our windows or we would be freezing. Is there a way to get proper ventilation without being cold?

[stoneyboy]

hamco,
You could beef up your heating system or fit a heat recovery ventilation system but these will cost a lot of money.
Suggest you get a de-humidifier with a reheat function this will remove condensation and to a limited extent, will warm up your home.
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[Colin1]

I've got a similar problem although the condensation tends to be less on the actual windows themselves and more on the metal window frames we have in our flat.

We try to ventilate the rooms as much as possible but the missus feels the cold too much to have the windows open for too long.

Is a dehumidifier the only other answer?

[stoneyboy]

Colin1,
Metal window frames will always attract condensation in the colder weather. A dehumidifier will reduce this problem but not cure it.
end

[ggaylmer]

I also have a problem with condensation on the inside surface of newly fitted timber double glazed units in an extension project. I have to wipe them every day and the frames have started to grow mildew before I've had a chance to dry them out and paint them. I fitted them with glazing tape(FLEXISTRIP) rather than mastic or glazing compound. This was recommended to allow ventilation around the glass units fom outside. Air can enter underneath the bottom bead from the outside and circulate around the unit. Otherwise apparently timber framed windows can have problems with condensation between the outer and inner glass if the seal blows. Some of my older windows already have that problem.

The condensation on the new windows occurs mainly near the edges of the inside surface, especially just above the bottom part of the frame. I tried silicone sealant along the join between glass and frame in case there was a draught of cold air leaking through, but it doesn't solve the problem.
Now I'm sure it is because of the circulation of very cold air all around the glazing units is cooling down the glass near the edges of the windows by conduction to the inside. There is a dilemma...glazing tape can cause condensation on the inside surface of the window and glazing compounds can lead to condensation inside the glazing unit!

Also another point...the glazing tape may stick fine when fitted in the warm weather but it is not effective at all in the cold as I have found. A unit I fitted fell out before I had a chance to fit the beading and another top-light fell out when I forgot to secure the beading with pins. Now it would be a cinch to break into a window with glazing tape...I don't recommend this tape.

Any ideas on this anybody?

[stoneyboy]

ggaylmer,
When glazing DGU's into timber frames I would recommend using neutral cure silicone not only to bed the units into the rebate but also to fill any cavities around the DGU. Also use DGUs without the adhesive tape wrapped round the edges which many maufacturers favour - the adhesive breaks down in time allow ingress of water.
If you want to use glazing tape fit the double sided security tape to the inner rebate only and again fill all round with neutral cure silicone.
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