Double glazing fitting questions

[David WE Roberts]

I've read various stuff, including Tim W's very useful thread.

I'm now starting to fit my own B&Q frames and as usual the questions I want to ask aren't quite answered.

(1) I have a pack of glazing packers from Screwfix (two, actually, 28mm and

32mm). The double glazed units are a shade under 28mm deep. However I have seen reference to 'bridge packers' which I think go at the bottom of the glazing and have some special characteristic which enables free drainage across the bottom of the frame. I can see two drainage slots at the bottom of the frame and also see that if I fill in the bottom channel with setting blocks then this would prevent water from draining from one side. No mention of this in the video.

So, do I need special 'bridge packers' which are different from glazing packers and if so where do I get them?

(2) Glazing packers. My glazing is roughly (just under) 28mm deep so I assumed that 28mm packers would be required. On removing the glazing beads from my first frame I note that the gap appears to be just under 24mm (the smallest width offered by Screwfix) with a lip about 4mm up on the glazing bead side of the frame only. Above the lip is about 26mm wide to a small ridge - the other (under) side of this lip holds the glazing bead in. This still doesn't seem wide enough to get the glazing behind, and the distance between these two ridges is about 40cms and the glazing is about

39.5 cms wide. So it is looking as though I have to build up about 4-6mm of glazing packers all the way round (24mm or under) until they are proud of this ridge before fitting the glazing unit. This will leave quite a large gap all the way tound the unit - far more than is required to accept the heads of the frame fixers. Is this usual?

TIA

Dave R

[Tim Watts]

On Tue, 15 Jun 2010 13:53:35 +0100, "David WE Roberts" wibbled:

I *think* the main purpose is to straddle any moulded ridges in the frame. On mine, the fixed glazing has such ridges but the openers are smooth.

I thought they were to do with water drainage, but as they do not occupy the full width, there's plenty of room for water to run around the packers.

Dare say you could survive without if you silicone a 4 or 5mm packer over the ridges (if any). Then loose pack from there as required. Choose a flat packer as the first one to silicone in - some are slightly curved and obviously after the silicone sets, they won't be able to flatten out and load the glass evenly.

I couldn't work out why Screwfix forgot to include the bridge packers in the mixed pack...

ebay have them in small amounts

No. On mine the typical total packing depth was 6-10mm depending. The glazing without packers would be a very loose fit.

[David WE Roberts]

In the spirit of DIY I suppose I could just cut a standard packer lengthways into strips and use this to construct a bridge packer.

Alternatively, I could just pop up to my friendly local plastic moulding place and get some there - have looked at

gives nice pictures of the various type and confirms the ridginess of the bridge packers.

They also show U shaped frame packers which allegedly slot together. Are these perhaps for packing out the sides of the frames whilst leaving space for a frame fixing in the middle of the U? Seems like a potentially good idea to fix the frames without distortion.

Also, the fit between the cill and the bottom of the frame is not particularly snug, but I presume there has to be a space at the front to allow the drainage channels at the bottom of the frame to drain out across the cfront of the cill.

Now measuring up my stock of self tappers to see if I have the required specific sizes or if I need to get some more.

Cheers

Dave R