Professional Double Glazing Installation

[arildthegreat]

We've just had salesman round to provide a quote (local company with good reputation). He made a big thing about their practice of measuring the window "bigger" so that they are installed "into" the brickwork.

This was made out to be their unique selling point. Is it unique?

Do alternative methods result in a poorer installation?

 

[Richard C]

Standard survey procedure is to measure at 3 separate points on both width & height, more on bigger windows but the squareness of the opening is also very important & must be checked. Use the narrowest horizontal & vertical measurements & deduct 10mm which would leave the fitter with a minimum 5mm around the frame to pack out & fit. You can go a little tighter in the opening but not much & only if the brickwork is very even & the brick openings are accurate & perfectly square. There is also a manufacturing tolerance on the frames which must be considered, this will vary with the size of frame but typicall +/- 2mm; but it can be more. If the surveyor gets it wrong the fitter will be seriously ****ed off & there is a chance he won’t trim the window but force it into a tight opening distorting the frame; he gets paid per window not on time. Gap around the frame may be typically sealed with expanding foam before a bead of silicone is run around the edge to seal the frame to the brick work. In some cases, UPVC beading may be used around the edge if the brick openings are poor but it should not be used to cover up poor installation or measurement. One point to watch is that although finishing off outside should always be included, remedial plaster work inside will not be unless you specifically ask for it to be & it will be extra & plastic beading around the inside looks terrible.

Basically what he’s told you is a typical salesman’s load of old crap.

 

[hillw]

PVC Windows should not be bigger than the gap they are intended to fill.
UPVC will expand a little and therefore there should be some tolerance and the brickwork is never square either
The salesman is telling you a load of nonsense, if the company has a good reputation then ring and ask to speak to someone who knows what they are talking about, but personally I wouldn't want to deal with someone who employs such poor sales people.

http://www.dgcos.org.uk/

will have a list of reputable companies in your area

 

[Alastairreid]

I think the method your salesman is referring to is the unit sitting hard against the brickwork of the external leaf as opposed to sitting inside it.
basically the window unit bridging the cavity.

 

[Richard C]

I think the method your salesman is referring to is the unit sitting hard against the brickwork of the external leaf as opposed to sitting inside it.
basically the window unit bridging the cavity.

Not something I'm familiar with, how does that work then

 

[Alastairreid]

The external aperture is around 10/15mm smaller than the internal.
The overall window size is taken from internal measurements.
The window slides through the internal opening and stopped at the rebates on the external wall.
The window is then fixed to internal leaf using window fixing cleats.

. View media item 30500

 

[Richard C]

I can see how that would work on new builds but would it be practical on replacement windows where the internal block aperture is usually the same size as the external brick leaf or smaller with plaster on the reveal!

A builder friend of mine uses a “Winfit” cavity closer/frame former fitting system on his new builds which is quiet nifty but got to admit I’ve not seen this one before.

 

[Alastairreid]

Quite agree Richard, unless the construction dictates otherwise, this method is also very disruptive to internal plasterwork etc on retrofits .

I have seen both methods used up here.