Replacing a double-glazed window

[Silverage]

Just been out cutting the grass and noticed this. We did hear an odd bang from that part of the house a couple of days ago but I’ve no idea what could have caused it. The inner pane is still intact.

Anyway, what’s the practicalities of swapping this out myself? In my mind it’s just order a new one of exactly the same size, prize off the beading, carefully remove the broken one, drop the new one in and replace the beading. Alternatively, does anyone have an idea of how much it would cost to get a local company to do the job?

I’ll take a look at my buildings insurance policy in the morning but I reckon the excess is fairly chunky.

[21TonyK]

Assuming the beading pops out easily its the simplest job going. Probably find a few blobs of silicon holding it it as well you will need to pick off but other than that just note the positon of packers before you remove the old unit. Stick the new one in and thats it.

I did every window in my house so I could clean the frames properly and replace all the seals. Simplest DIY job I've done in ages.

[Promised Land]

If doing it yourself you’d need a hand if you don’t generally replace units as that’s quite a large one for one person.

Most important part is knowing your spacer bar size, the glazier will ask for 4-XX-4, 4being 4mm glass and it’s toughened the XX being spacer bar width, get that wrong by a couple of mm and the beads won’t go back in.

To determine the width measure the complete unit width in the top opener, subtract the thickness of the beading both sides, ie a straight edge across the unit, measure in to the glass, this will then give the sealed unit thickness, take off 8mm for 2 panes if it’s standard glass and you’re left with the spacer bar width.

Edited by Promised Land on Thursday 27th June 18:46

[Mercdriver]

I was quoted £350 to change a double glazed unit size about 1.2x0.8.

Utube videos demonstrated how to do the job and recommended a fancy tool to remove beading.

Beading removed from inside is normal I think otherwise the tea leafs would have no problem breaking in.

I did not buy the tool but used a very sharp chisel to prize them up, easier to prize the longer bead depending if pane is picture or portrait.

First one is hardest, after that you get confidence and it is easy.

I wanted to measure the sizes of the existing glass rather than estimate before removing the beads.

You need to know the thickness too, I used a steel rule and a vernier gauge to accurately measure the dimension. Measure across the frame the deduct the gap from a steel rule placed on the frame and use the vernier to measure from steel rule to glass face.

Local double glazed supplier charged me £120 for a new panel.

Think about how you get your new panel home depending on size and weight how do you get it home?

I am 77 and not the strongest , but a neighbour gave me a hand to lift new one in.

Took two minutes to refit beads, do short ones first then the longer ones, insert them at both ends then use a block of wood to gently seat them against the glass.

It is not difficult just take your time, easier next time

[V8 Animal]

If you know the size, type of glass, energy saving glass, spacer bar type, overall thickness.
Otherwise about £350 fitted by a company.
Your strimmer broke it.

[Wings]

From a Bristol company I recently replaced a double glazed unit
430 x 840 clear glass 4/6/4 for £20. From your photo OP it may be that the beading of the window is exterior, so a dab of clear silicone when replacing the beading.

[V8 Animal]

Wings said:

From a Bristol company I recently replaced a double glazed unit
430 x 840 clear glass 4/6/4 for £20. From your photo OP it may be that the beading of the window is exterior, so a dab of clear silicone when replacing the beading.

It’s internal glazed.

[Silverage]

I am tempted to have a go at it myself. I’ll measure it up tomorrow and get some prices for a new unit.

[hidetheelephants]

What everyone else has said; pop the beading out with a wallpaper scraper or similar, record the positions of the wedges and shims and order a replacement glass unit. The hardest part is getting the size right, but it's easy enough to measure once dismantled. A suction glass lifter makes refitting the unit much easier, especially in the larger sizes. Take care to not damage or lose the beading, as replacing it is difficult unless quite new, as there's no standard for beading and consequently eleventy twelve varieties that all look the same but aren't.

[Mercdriver]

I tried a wallpaper scraper but it was not thin enough to get into the gap between the frame and the moulding, that is why I used a chisel, very carefully and very light taps of a hammer so as to not mark the moulding.

The gap on my windows is very tight so much that I struggled to find if glass installed from inside or outside but I guess for security the glass is installed from the inside?

[hidetheelephants]

To get it started I found the wallpaper scraper really needs a thump, either with the palm of your hand or a mallet; the plastic is tough and springy and the beading pops into and out of place. A chisel would work but I'd be worried about damage, perhaps use a blunt one?

[Mercdriver]

Agree I just did not have the confidence to give the scraper a sharp hit. Probably if I was doing another window I would start with a scraper, first time is always the worst as the Bishop said to the Actress

[21TonyK]

I found a wide (sharp) chisel tapped in started the movement then used a plastic car trim tool just to lift the bead enough and get a finger under it to pop it out. Long length first then just worked around in sequence.

[J6542]

Quarter moon knife is what you want. You can get a cheaper one for about £8

[LooneyTunes]

hidetheelephants said:

What everyone else has said; pop the beading out with a wallpaper scraper or similar, record the positions of the wedges and shims and order a replacement glass unit.

Worth having a few extra shims/packers to hand in case the size of the glazing panel ends up being slightly different to what was in there before.

[V8 Animal]

Put a dust sheet down the broken glass will go everywhere’, in fact remove the broken glass first then you can measure the spacer bar normally 16 or 20mm
Inside where bead meets frame measure and deduct 10mm
Order unit, could be coated glass though if s heated conservatory.

[Silverage]

I’ve rung round a couple of local firms this morning and I’m getting quotes of £130-150 for the whole job, subject to inspection. I priced up the unit itself at £70, so I think for another £60-80 I might let someone else do it.

[Mercdriver]

You are a wimp!

[J6542]

It’s a no brainer at that price, if you break the new one, which you can easily do by dinking the edge of a toughened unit, then it would cost you about that anyway.

[Silverage]

Mercdriver said:

You are a wimp!

Correct ;-)

It's a fair size, and I imagine a fair weight, of a unit though, half of which is made up of broken glass being held together by I'm not sure what.