Stormproof casement windows..... New territory!

[Harrris303]

Hi everyone, I just posted this in the design section but wasn't sure if that was the right place so I'll give it a try here instead!

I've agreed to make a large casement window for someone (3 sections, 2 full-size casements opening on either side, and a fixed one in the middle with a small opening one at the top).

They sent me some photos of the window I'm copying and it turns out to have stormproof casements, which is not something I've done before. I'm currently a bit of a student of joinery so I've made a couple of simple casement windows but nothing more complicated.

I'm sure there will be many more questions but my main one is this:
When designing and making the casements, would you make them deliberately oversized, too big for the frame, and then cut the rebate around the outside once they're assembled, so they then drop in but overlapping the frame on the outside?

If this is the case would you then have to change the design of the mortice & tenons to account for the wood you'll be cutting away at the end?

I've tried to explain myself as clearly as possible so I hope someone out there has a rough idea of what the hell I'm talking about haha. Thanks in advance for any help you guys can offer. Cheers.

 

[MMUK]

Whenever I've had stormproof windows spec'd by an architect, I've fitted flush casements with big wide pineapple off gaskets around the sash. The other design I'm aware of is a normal casement with a larger overlap than normal and fitted with cranked hinges.

 

[Harrris303]

Hi thanks for the prompt reply. From looking at the photos it seems like the bit of the casement which overlaps the frame isn't planted on and is part of the solid wood used in the stiles and rails of the casement. I found a useful diagram online (attached) which pretty much illustrates what I'm after, my issue is to do with the process of actually putting it together.
I can't decide whether it would be best to cut the rebate which overlaps the frame before assembly, or just make the whole thing too big for the frame and then router out the rebate after so it slots into the frame.
(I hope that makes sense in some way!!)

 

[RogerS]

Not a great fan of stormproof windows, myself. Apart from looking hideous there's too much end grain knocking about for my liking. If i had to make some, I'd plant on the stormproof bit with epoxy.

 

[Harrris303]

To be honest I was thinking the same. I might suggest that to the client and see what they say. They're up for doing it on the cheap so they might just agree! haha. Cheers.

 

[murdoch]

Hi, yes your right, to make a stormproof sash you would make the sash oversize and then spindle mould the rebate on so it fits perfectly with a 3mm gap between the window frame rebate and the sash, the sash then overlaps the frame by around 12mm so a total rebate size of 15mm.

Because adding this rebate along with the glass rebate will make the sash profile quite thin in the middle, there will not be enough room for a wedged tenon so you will need to do a bridle joint and put a pin in it to hold it in place over time. if you've got it, use cascamite glue.

Hope this helps and you understood, we're in suffolk so you can always pop in if you need some help.
cheers

 

[Harrris303]

Brilliant thanks very much, that's really helpful. Very well explained!
I'm actually right up on the North Norfolk coast so it's a bit of a trek to Suffolk but I'll bear the offer in mind in case something goes wrong, thank you. Hopefully it'll all go smoothly but it rarely does!
Cheers.

 

[williams1185]

the easiest way to make the sash is to measure the opening size add on three quarters of an inch make the sash to that size ie 18 inches by 18 inches plus the three quarters becomes 18 and three quarters once the sash is made rebate the whole sash all around half inch deep that gives you hinge clearance with no binding

 

[Dusty]

Here are some pictures of a shop made storm prof I had to fit

 

[Harrris303]

Thanks for the pics, especially the bottom one. It shows the bridle joints that Murdoch mentioned, and seeing clearly how the hinges work gives a whole new angle to it. Looks like you really have to plan ahead with the design to make sure the hinges will actually fit! Thanks very much.

 

[Dusty]

Glad to of been some help .

one window was ordered wrong so modified so we had some parts from it spare , was ordered 8 units not 4 , so I have some of the window beads and one of the glazing bars in the workshop which I can photograph if you like . These units were fitted with either 22 or 24 mm glazed units . I will measure the hinge set for you too if you like as there are many available . Looking at the other pic I have the main frame is 67mm thick to allow the casements . The rebate for glass and beads is 41 mm . These were manufactured by either Premdor or Jeldwin . So meet the regs etc .

 

[Harrris303]

Cheers, I'd be interested to see any more photos you feel like posting.
The people I'm making it for want to reuse the old double-glazing units so at the moment I'm waiting on them to tell me the dimensions etc. To a certain extent that's going to dictate the specs of the casements I guess. I'm still a bit in the dark at the moment!

 

[RogerS]

.....
The people I'm making it for want to reuse the old double-glazing units so at the moment I'm waiting on them to tell me the dimensions etc.....

Not a good idea for all sorts of reasons but the main one is that if they fail shortly after you've made the windows then they will blame you and expect you to sort them out. I would run a mile. OK if it is your own windows but not for a client.

I guess you could get them to sign something excusing you from any failure of the dgu's.

 

[MMUK]

.....
The people I'm making it for want to reuse the old double-glazing units so at the moment I'm waiting on them to tell me the dimensions etc.....

I'd tell them to politely pineapple off and walk away. You'll be opening up a whole can of worms if you take this job on.