Using frame extenders on upvc windows

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Hi

Just a random query.

Say you have a upvc window that requires frame addons/extenders because they've been measured 'wrong'.

Does it look cr*p (from outside) if you can see the joint between the actual frame and extenders after the window has been installed?

Thanks
 
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It's not ideal but sometimes they are needed to clear fascia boards etc. The ' gap'shpd just look like a continous straight line. If you are careful you can get silicone in it mask it a little or maybe trim over it?
 
That's really helpful. Cheers

Do you reckon you'd lose much heat through the gap? I was thinking of putting some expanding foam tape in the extender but I bet that's harder than it sounds
 
The extender should be the same profile as the actual windows, so I wouldn't expect you to lose any more heat than you would through the actual frame, as goes the gap... there really shouldn't be one. The extender should clip flush( might need to use a rubber hammer , and clean out welded joints a little) , leaving literally a line where they join
 
The extenders if fitted properly (clean up welds, hammer) are more or less invisible. What can look odd is if there's a lot of frame visible and the frame sides are much wider than the top or bottom.
Is this your measuring faux-pas or a fitter?- if the fitter has screwed up, get them to do it again properly.
 
Hi oldbutnotdead

Here's the too long answer..

Originally the property had sash windows installed, but these have long since been taken out. We've still got one of the original windows in a cellar though so you can see what they looked like.

IMG_6173.jpg


When the sashes were still there, a few inches of each side sat behind external brickwork. But when replacements were fitted, the width of the new windows was only as wide as the width of the opening in the external brick (so nothing of the replacements was set behind external brickwork) if that makes sense?. It looks like to allow fixing to the masonry, 2x2 battens were then installed each side of the frame. You can see one of the battens at the side of the window below. Normally the battens and window casing are covered by thin ply panels but I've removed these.

IMG_6196.jpg


I have come along and found the currently installed windows very cold and draughty even though they are all 10 year old WHS Halo units in good condition. The silicone seal around the outside of the window has holes in it you can fit your little finger through, plus there's no insulation of any kind between the frame and the building.

For ref, the frames are 70mm deep but 15mm of this sits in the opening of the external brickwork. So one of my thoughts was to move the window 15mm inwards (towards the house) so I could then fit frame extenders and have the window unit sit behind the external brickwork like the sashes used to. My reason for doing that was to create a better seal against the brickwork, make it easier to insulate etc. But I'm not sure of the exact benefit of moving the frame inwards over just moving the battens over an inch or so and insulating the space where the battens currently are.

So my question on frame extenders was part of a bigger plan :)

Thanks
 
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What you're planning is a perfect use for frame extenders (I've done the same in a similar setup). Placcie is a better insulator than wood, it'll look better, worth doing.
 
oldbutnotdead said:
What you're planning is a perfect use for frame extenders (I've done the same in a similar setup). Placcie is a better insulator than wood, it'll look better, worth doing.
Click to expand...

That's great to know.

What did you use to seal the frame against the 'backside' of the external brickwork? I've seen this on YouTube that looks good....

 
Silicon on the external brick/placcie edge, expanding foam internally between the side of the frame and the brickwork. Nothing on the face of the window.
 
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