Timber thickness glazed doors

[Sebb]

Hi all, I’m looking for guidance on minimum timber thickness for glazed doors, they’ll be 720 x1880 with 4” top rail and stiles and a 8” bottom rail, probably going to build in larch or cedar, maybe oak.

Is there a resource anywhere which gives minimum specs for all this or is it just a case of 45mm or?...

I have some larch I’d like to use but it’s only 41mm after planing and much lighter and wider growth rings than larch I’ve used previously, I think I should probably not use it but money saving part of me wants to..

many thanks in advance

 

[Doug B]

What sort of glazing & what type of door ?

 

[Sebb]

It’ll have 18mm toughened double glazing, doors will be hinged. rails will be tenoned into the stiles, it’s for a summer house/shed. 12mm square cedar stops on outside to match other units and inside I was thinking of stops again rather than rebating the frame but inside stops can be rebated so part sits on the inside frame for a bit more security

 

[johnnyb]

I've got a pair of oak double doors single glazed about 28mm thick. made in quarter sawn oak. rebated meet and they are great flat and never swell much.

 

[Jameshow]

You will have to use 10x12mm on the inside of that bothers you.

Cheers James

 

[Doug71]

Ideally the minimum rebate you want for standard DG units these days is 15mm or you will see the edge/spacer bar of the unit. This allows for 12mm sightline of the spacer bar and 3mm clearance all around the unit.

 

[MARK.B.]

Thanks for that info Doug, I wonder how many times little nuggets of information like that have saved some head scratching and to be honest a fair amount of swearing on my part over the years , it is one of the reason's i like forums like this .

 

[Jacob]

If it's a summerhouse/shed do you really need DG? They'd be very heavy and you'd need a wide lock rail too, for more M&T structure

 

[Sebb]

thanks all for the replies and info so far, good stuff. Yes they want DG as they already have elsewhere on it And they want one glazing unit per door- no lock rail. do you think just bottom and top rail is going to be asking too much of larch or cedar?

 

[dzj]

It's about 15 kilos of glass. Shouldn't be a problem if packed properly. Even for 41mm.
Go for traditional M&Ts. 2 on the bottom rail, horns and all that...
Not a job for loose tenons.

 

[Jacob]

thanks all for the replies and info so far, good stuff. Yes they want DG as they already have elsewhere on it And they want one glazing unit per door- no lock rail. do you think just bottom and top rail is going to be asking too much of larch or cedar?

I don't think a 4" and an 8" rail are enough. I'd go for 12" on the bottom and I'd still worry about lack of lock rail. It's not about thickness it's about glued surface area of mortice and tenons resisting collapse.
Remember basic rule; the client is always wrong. If it isn't a good idea and it fails they won't thank you for not telling them.

 

[Nuffield]

Hello,

Going back to my joiners shop work days, min size ex 4 -1/2 (can go 3 1/2 if light weight) x 1- 1/2 stiles and top rail ex 9" bottom rail. Mid rail ex 4 -1/2, glazing bars ex 1- 1/2 x 1 -1/4 (internal glazed doors ) . If you want muntings - same as top rail. external door ex 2" .

Hope that helps.

 

[Jacob]

Hello,

Going back to my joiners shop work days, min size ex 4 -1/2 (can go 3 1/2 if light weight) x 1- 1/2 stiles and top rail ex 9" bottom rail. Mid rail ex 4 -1/2, glazing bars ex 1- 1/2 x 1 -1/4 (internal glazed doors ) . If you want muntings - same as top rail. external door ex 2" .

Hope that helps.

That's more like it! 4 1/2" is handy as you get it out of 9"
What about 4 1/2" stiles and rails, 9" bottom rail? Still a bit on the flimsy side perhaps, with no lock rail.

 

[Sebb]

Thanks all for the advice, I’ll beef up the width of the rails and stiles and definitely m&t with horns too as described, much appreciated

 

[Adam9453]

Personally I’d go 5inch+ for the top rail and 10inch+ for the bottom rail. There is a lot of load on the top joints, must be properly wedged M&T joints and thoroughly glued (in a nice warm environment to ensure full curing of the glue inside the joint, the cold we’re having at the moment makes glue joints powdery and weak). The double glazed unit itself, while heavy, does add an element of ridigity if properly packed and sized for the rebates/beads etc. We typically make our joinery doors 54mm finished thickness and we start off with 63mm rough sawn timber to achieve it. Another thing which we have done with them in the past is rip the timber in half, flip and glue back together to create better balanced timber to resist warping. As you are not going for a lock rail, you will need to check the dimensions of the lock you plan to fit to ensure your stiles are wide enough to accommodate the mortice for the lock body.