Selecting glazing packers

[chris_d]

Dear all,

I have to glaze 18 vented and drained timber window casements with external beading. I'm using 24mm DGUs and following the D3 method statement from Hodgson Sealants which uses their Flexistrip glazing tape (thanks to Dibs for suggesting it) as described here:

http://dij.webs.com/The_D3_Glazing_system_aw_Hodgson.pdf

As I'm new to glazing, I have some questions about glazing packers which I believe is a banner term encompassing several sub-types including: setting blocks, location blocks, bridge packers, wedge packers and bead blocks.

Now, the method statement clearly identifies setting blocks and location blocks. I have read elsewhere that setting blocks are known as bridge packers which incorporate drainage grooves that shed water from the bottom rebate - although all the ones I've observed are always 100mm long and with incremental widths that coincide with DGU sizes eg 24mm, 28mm, 32mm but they appear to have the grooves running in the wrong direction (along their length) unless you're supposed to cut them along their length and place in the rebate with the grooves running perpendicular to the DGU?

However I can't imagine that professional glazers waste their time cutting bridge packers plus why would they have widths that coincide with DGU widths? Please advise.

Next query, the bottom rebates are sloped to shed water, hence using a setting block of constant thickness eg 6mm would not offer support to both panes of the DGU as the top face of the packer would be parallel with the rebate slope. So are setting blocks meant to be wedge shaped? If so then I am struggling to find bridge packers that are also wedge shaped - any suggestions?

Next query, can someone please confirm that location blocks are supposed to be wedged as I believe that is needed to 'lock' the DGU in position (side to side only)?

Next query, the method statement identifies bead packers that are to be used to space the bottom 'hockey stick' bead away from the rebate to enable water to drain away. Now, is a bead packer completely separate to a setting/bridge packer or if I use extra wide setting/bridge packers beneath the DGU can they double up as bead packers? However, I can only find bridge packers in a maximum width of 32mm (ignoring the parallel groove issue) which would only offer ~5mm* of support to the 20mm wide hockey stick bead which IMHO would cause it to twist and/or split when pinned. I can buy 20mm bridge packers which would seem more sensible for the 20mm wide hockey stick bead.

Help me please - I just want to buy and use the correct packers!

Thanks,
Chris

* 5mm = 32mm - 24mm DGU - 2 x 1.5mm of compressed Flexistrip glazing tape.

 

[jasonB]

As the window section is also in line with those grooves in the blocks it allows water to travel along the length of the cill section to the holes.

If the grooves ran the other way you could end up with two dams stopping water flowing along the extrusion to the holes.

This certainly applies to PVC windowns

 

[Lons]

What Jason said.

As far as I know they are all made with PVCu frames in mind although I haven't specifically looked for others as I haven't fitted timber windows for a long time. My supplier provides loads of packers with every frame and I use them for loads of other things as well.

Only thing I would add is to be careful on opening windows as they should be wedged correctly at the sides to stop the window dropping out of shape (similar principle to the bracing on a gate or door).
I'm no expert and often long gaps between window jobs so memory being what it is, I always have to think hard and work it out but plenty of info on the web.

Bob

 

[chris_d]

Thanks Jason,

I see how your comment applies to internally beaded PVC frames with drainage holes but I have externally beaded and vented/drained timber frames without explicit drainage holes. However, if you are suggesting that water migrates along the grooves by capillary action then I can see how they would work when installed parallel to the DGU but provided that they have vertical holes in them to enable water to get down to the grooves in the first place.

BTW: I've found an excellent glazing guide by SEAC which talks about compensation packers to allow for sloping/stepped rebates (reinforcing my paranoia) and also discusses the sizing and placement of packers in more detail. The guide can be found here:

http://www.seac.co.uk/uploads/brochures/Glazing_Guide.pdf

However, SEAC don't seem to make sloped compensation packers (just stepped for odd PVC profiles) so I've just called the timber frame manufacturer to check whether I'm being paranoid - waiting for a 'technical' person to call me back.

If anyone is interested, I've found a supplier of bridge packers (for setting blocks) in sensible quantities and with sensible prices, they also sell normal flat packers (for location blocks), their website can be found here:

http://www.hdhardware.co.uk/index.php?cPath=293_294

Still interested if anyone can advise on the sloped rebate packer issue.

Thanks,
Chris

 

[Dibs-h]

Chris

That's why I went with the fully bedded method. Seemed far less hassle then the vented and drained method.

In my case I used some brown blocks - about 2mm thick, about 10mm wide and about 25mm long. Managed to get a handful from the glaziers who I bought the FlexiStrip from.

What do your vented\drained casements look like? Can you post up a picture of one of the rebates & beads - I'm curious.

Cheers

Dibs

Edit: Chris, you might find the following useful - http://uk.saint-gobain-glass.com/b2b/de ... ssaire&c=L

 

[chris_d]

What do your vented\drained casements look like? Can you post up a picture of one of the rebates & beads - I'm curious.

Hi Dibs,

Here you go:

The window manufactuer never called me back! Grrr!

 

[kostello]

looks to me like youneed to use sloped packers under the galss and a 2 or 3mm packer every 6 to 8" under the bottom bead to raise it up to allow for drainage..................

i think magnet windows are like that.............

or use these: http://www.ironmongerydirect.co.uk/Prod ... pack_of_25

but you have to machine the bottom bead to suit........

EPDM gaskets on the outside on the beads are easier than flexistrip...............................