Cool air around double glazed windows

[H F]

All our windows are double glazed and we wood fillered all tiny cracks. The house is warm (it’s freezing outside) and we can feel some cool air around the sill (not a draft). Is this normal?

[Mr Punter]

It is very common.  Very little effort goes into insulating window heads, cills and reveals.

[H F]

9 minutes ago, Mr Punter said:

It is very common.  Very little effort goes into insulating window heads, cills and reveals.

Bummer. Are there any tricks to combat this?

[Alex C]

13 minutes ago, Home Farm said:

Bummer. Are there any tricks to combat this?

Yes,

Fit the window in to a properly sized opening in an insulated wall and in line with the insulation not in front or behind it. (not always easy in a retrofit)

Foam carefully around the window when it is installed 

put a strip of insulation as a break at the rear of the window board

You can also fit foam backed plasterboard around the opening on the inside part covering the edge of the frame to reduce any bridging.

Edited November 14, 2019 by Alex C

[H F]

So this would require removing the windows? If so, that’s not a realistic option for us. 
 

Guess we’re stuck with shoddy workmanship for the foreseeable future.

[Mr Punter]

You could just take the cill up and have a look.

[H F]

Would taking the sill out be as simple as just cutting around the edges?

[Alex C]

4 minutes ago, Mr Punter said:

You could just take the cill up and have a look.

Is that a little trim at bottom of window on the window board? If so I bet it is hiding a bloody great big hole at the bottom of the frame. You could remove the window board and refit with some thin celotex underneath and a the back edge. Or just put up some heavy curtains.

[H F]

That is the only window with trim at the bottom, and it’s the draftiest. Thanks for pointing that out... I’ll deal with that in the days ahead.

[H F]

Looks like your diagnosis was spot on. Thank you.

[Alex C]

Fill it with expanding foam. Maybe put some tape on the window board to stop any overspill sticking to it. Neatly trim it back when dry and put the trim back.

[Onoff]

Basicslly DG fitters of old were on a price so it was bish, bash, bosh as quick as. Surveyors would under measure so the window fell in with no drama. Fitters just covered the huge gaps with trim. No foam or Compriband.

 

(Check out White Gold on Netflix ? ).

 

Have a look at what I did wrt my bathroom DG window. Nov 9 onwards. Miles better than it was but I wish I had removed the window and brought it further in. No draught now but the air space can still feel cold near the window.

 

 

[H F]

13 hours ago, Onoff said:

Have a look at what I did wrt my bathroom DG window. Nov 9 onwards. Miles better than it was but I wish I had removed the window and brought it further in. No draught now but the air space can still feel cold near the window.

I don’t think I’ll be able to move entire windows... there’s just too many. 
 

After our bathroom is done, I’ll be turning my attention to some of these sills where the draft is more noticeable and seeing how we can draft proof them better.

The work is never ending at the moment, and unnecessary as most of it stems from shoddy workmanship.

[joe90]

6 minutes ago, Home Farm said:

The work is never ending at the moment, and unnecessary as most of it stems from shoddy workmanship.

 

This is why attention to detail when building gets you much better results than most houses even with the same insulation spec.