Fitting window restrictors - screwing into uPVC

[hsabbers]

Hi,

I've bought some concealed window restrictors like these to fit to our our uPVC double-glazed units:

Untitled

• hsabbers
• 5 Nov 2008
• 1

...but, I'm wondering what size screws would be wisest to use? The worry isn't so much with the frame, where I'm happy to use 19mm (3/4in) screws but on the opening sash, but where to the restrictor stud and what size screw to use?

Part of my concern is that the double-glazed-unit's sash isn't flush all the way around -- there's a channel all the way around that traces the glazing unit (I have no idea how common this is, or even if my description makes sense) so here's another photo, with the stud held in place by my thumb:

Untitled

• hsabbers
• 5 Nov 2008
• 1

As you can see, the restrictor stud seems to be designed to exactly to straddle this gap but the screws would then have to go through the stud and into thin air for about 10mm before entering the frame. And behind this channel, of course, is the double-glazing itself. I'm concerned that screwing here to any depth could compromise the sealed glazing (though I see that the sliding bolt mechanism is attached below using screws into this same area).

Anyway, any advice much appreciated.

Harry.

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[Symptoms]

harry - perhaps you could take an existing screw out and measure it, then fit your new tackle with a similar size. Maybe drill the pilot hole for the screw, insert a probe (straightened paperclip) to act as a depth gauge to double-check if you are nervous.

 

[wms]

pz 19mm screw required to for the restrictor mushroom and a 19mm or twenty five mm to the frame


you may even find the shoot bolt screws are 25mm remove one and make that your max size do buy decent screws or they will rust in no time.

 

[hsabbers]

you may even find the shoot bolt screws are 25mm remove one and make that your max size do buy decent screws or they will rust in no time.

Thanks WMS (and Symptoms). I removed a screw from the shoot bolt and, remarkably, they're longer still -- 30mm! So a fair bit of room to play with. But I think I'll go with 25mm screws just to play it super-safe. So, self-tapping I suspect is best -- where do you recommend buying 'decent' screws (not being facetious -- just trying to learn!).

Harry.

 

[wms]

For the type of screw you req try popping in to your local window manufacturing company they will have the correct screws and should sell you some or as we have been known to do on occasion, give you some.

you may find that the sash and outer frame has reinforcing in , then you would req a self drilling screw takes the work out of fitting to sash. as I say a small local window company is your best option plus you will not need to buy a box of them.

 

[hsabbers]

pz 19mm screw required to for the restrictor mushroom and a 19mm or twenty five mm to the frame


you may even find the shoot bolt screws are 25mm remove one and make that your max size do buy decent screws or they will rust in no time.

Thanks all. I've now completed this job successfully. Used 19mm (3/4in) screws for both the restrictor and the stud bolt. Nice and secure and all working fine.

Cheers.

Harry.