How much gap should there be under UPVC window installation

[MandyP1]

Hi, just wondering if anyone can help me with this.

I have just had new UPVC glazing fitted by a company, and wonder if someone can tell me how much gap should there be in new UPVC window installation. The windows are measured/fitted correctly widthwise, but, are short by approx 20-25mm - that is above the existing mortar bed, this means when filled the mortar bed will end up 35mm and look ridiculous. The company keep telling me this is standard, but, I have had windows installed in the past and never, ever, had a gap below them like this. After they initially patched the mortar up the majority cracked and dropped out. They are currently trying to convince me this is standard, and the windows should have this amount of gap below them, it just sounds rubbish to me. I don't know how they have managed to get the width right and make such a mess of measuring the height. Can anyon please advise. Many thanks.

[aeyres]

They are trying to get away with poor surveying & therefore incorrect window sizes.
20-25mm underneath is far too much tolerance. 10-12mm all round is acceptable for PVC applications.
I would request that they replace the window, or at the very least provide a 'chunkier' cill profile that they can re-fit under the existing window.
Don't stand for poor quality installations, i imagine you have paid good money to this company. If you haven't paid them the full balance, hold back on payment until you are happy. You will quickly see their attitudes change when they are chasing money!

[glazier7]

it sounds like a bad survey, on the interior, do the windows look the same all round, it might be that in the case of a bathroom or kitchen, the tiled internal window cill has been built up, when in which case the surveyor has taken this into account.

[halfpenny]

Hi I have got exactly the same problem. The window compay surveyed the property to remove the old aluminuim windows but leave in a wooden battern that was there(inbetween bottem edge of window and brick) on the ground level windows. when the fitters came they remove the wooden batten which resulted in a massive gap at the top edge of the window and door that are at ground level, as the window sat lower down than surveyor had planned as the battonthat the old window sat on was no longer there.

The company have offered to come back and fill the gaps (on the four units that are like this) with foam. I didnt find this aceptable as i had paid over £3500 for doors and windows that fit the holes. I did not want short windows with foam filler. I asked consumer direct my rights they said I should write to the company and state what i would like to be done I.e. replace the windows and doors with some that fit.

I have written three letters using consumer direct templates i have had no response so now have the options of small claims court or getting them filled with foam filler.

I have looked up ususally tolerances for gaps round windows along with british standard for window fittings and british plastics federation code of practice who seem to make the rules on these thing. It has been very hard to find an offical document that sates acceptable tolerances. But there is a few websites I found which may be usful to you. :www.degema.co.uk/pdf/files/meas_fit_doors pdf and
Google "window-warehouse.co.uk" (page 3)

It seems from what i have read a normal acceptance is 10-12mm but i am not a window fitter so dont quote me on that.

My windows have gaps at the top of 6.5 cm yes that cm. The foam filler may cure the drafts but i will feel ripped off if i accept this solutions as i didnt want short windows with filler but it may be a big battle to get them replaced.

What happend with yours i see your post was dated July are you any further ahead?

I am sorry this may not be of much use to you in solving your problem. :(

[quote="MandyP1"]Hi, just wondering if anyone can help me with this.

I have just had new UPVC glazing fitted by a company, and wonder if someone can tell me how much gap should there be in new UPVC window installation. The windows are measured/fitted correctly widthwise, but, are short by approx 20-25mm - that is above the existing mortar bed, this means when filled the mortar bed will end up 35mm and look ridiculous. The company keep telling me this is standard, but, I have had windows installed in the past and never, ever, had a gap below them like this. After they initially patched the mortar up the majority cracked and dropped out. They are currently trying to convince me this is standard, and the windows should have this amount of gap below them, it just sounds rubbish to me. I don't know how they have managed to get the width right and make such a mess of measuring the height. Can anyon please advise. Many thanks.[/quote]