Drafty UPVC windows

21 Jan 2011
Reaction score
United Kingdom
Dear all,

Are there any UPVC window fitters about?

I recently had all of my windows replaced with the latest and greatest UPVC offerings. The fitters came and went without too much fuss and everything was fine for a few weeks.


It was a bit windy last night, and whilst eating tea in the kitchen my wife and I noticed the blinds on both kitchen windows moving slightly, even though the windows were shut. On further investigation I found that there seemed to be a draught coming from the bottom edge of the window where the frame meets the internal window sill. I also found while poking around that I could move the bottom frame of the windows quite considerably.

We already have concrete sills on the outside however the fitters fitted a stub sill (or that's what they called it) to the windows so that they are the right height on the inside to get the glass in. It does appears though that neither the stub sill or window frame is attached to the concrete sill in any way, and what's more the stub sill isn't even sealed to the concrete sill with silicone sealant.

Surely this isn't right? I've had a poke around Google and can't quite make out whether the window should be screwed to the concrete sill or not, but surely it should have been sealed? What's the point of having triple A rated windows if they are as draughty as the crappy ones I had replaced?


Sponsored Links
Should be fixed and should be sealed. Get them back to put everything right, i'm assuming they are still covered and the company still trading?
They should be sealed together at the bottom, but not screwed as this would damage the drainage channel, and possibly the damp course of the wall.

Expanding foam in any gaps would resolve it from the sounds of it.
Sponsored Links
The cill should be screwed to to frame but also the cill should be sealed underneath to the concrete cill, I wouldn't screw down, but properly sealed it shouldn't be draughty at all
Hi all,

Thanks for all your replies. Yes, the company are still trading so I'll get them back after Chrimbo to sort it out.



DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local