wooden window frame joinery

[Random Orbital Bob]

I'm making two Oak windows for a friend and would like to know the right way to join the upper frame rail to the stile. I've included a pencil drawing to illustrate the question but put simply: do I have the rails longer in which case they cover the stiles end grain or the reverse? My assumption is the rail should cover the stile because end grain facing upwards gives easier penetration of water by gravity but that's pure guess work as this is my first window.

Help is appreciated.

 

[morturn]

Left drawing, with an M&T joint. Leave the rail longer for the horns, you brick those in after fitting.

 

[Jacob]

If that's a frame to go in the masonry then left and it's called jamb and head.
If it's a light to go in a frame then right and yes it's called stile and rail.
Either way - oak not good choice for windows!

 

[Random Orbital Bob]

Brilliant...thanks. That matches what made sense to me ie cover the end grain that would be facing up. In this case there won't be any horns as it's going into an existing space (old house) where there aren't any from the existing window. It'll be screwed through the frame into the brickwork. I will double check with the owner though in case he wants to introduce horns.

By the way, I meant to repeat the question for the sash joinery...is it the same? Obviously no horns but do the stiles cover the rails or t'other way round?

Thanks again.

 

[Random Orbital Bob]

If that's a frame to go in the masonry then left and it's called jamb and head.
If it's a light to go in a frame then right and yes it's called stile and rail.
Either way - oak not good choice for windows!

Crossed in the ether. Thanks for clarifying that. I think I probably knew it was a jamb and a head but just not that familiar with the jargon. What you're calling a light, I've called the sash ie the bit that opens and is hinged to the frame.

I've already advised the owner (who is a builder by the way) that oak isn't a great choice but he's replacing an existing one and prefers like for like.

 

[Random Orbital Bob]

Out of curiosity, whats the thinking behind covering the rail end grain in the light rather than the opposite as in the jamb and the head?

 

[deema]

Two reasons I understand. Sashes were dovetail M/T joints originally, which required the styles to be longer. The dovetail M/T was to carry the weight of the glass since glues were not that brilliant.

I also understand that It allows the water to drop off the end rather than run over end grain

 

[Random Orbital Bob]

Thanks Deema

 

[RobinBHM]

Ive always assumed in a casement window frame the cill runs through as it allows for horns.

We paint end grain sealer on the jamb ends and around tenon, and on the jount area of mating part. No glue used in assembly.

Frames can be done with stop tenons. The tenon can be just 1/2" thick as its a location joint. Mortice goes in rebate and next to it.

Modern window frames can have a separate cill -much easier than an all in one to machine.

Sashes are glued of course.

 

[Jacob]

A frame in the masonry is designed to be load bearing with a beam (the head) going across which may also have ‘horns’ to locate it in the masonry course. Supported by two columns (the jambs).

A hinged light, casement, sash, window, door, gate, etc. hangs from the hinge stile - so this is the principle component and the other bits are secondary. Usually made mirror image for simplicity but in larger gates you see a big primary hinge stile, top rail as secondary and braced, like a gallows, and everything else hanging off. Ledged/braced door similar - the main components are the hinge stile, the top rail and the brace - everything else is secondary.
Which doesn’t quite explain the usual rail/stile set up, but the only person who does it the other way is Krenov - so the traditional way must be right!

A sliding sash on the other hand is supported equally on both sides which means they can be much wider and lighter than a hinged casement. There’s more structural strength in the vertical glazing bars which go through and hold it all together, and allow for a very thin meeting rail. Horizontal bars are cut. Opposite in a hinged casement.

 

[RogerS]

.....
I've already advised the owner (who is a builder by the way) that oak isn't a great choice but he's replacing an existing one and prefers like for like.

OK..I'll bite.

Why not ?

Lots of houses round our way have oak windows.

 

[ColeyS1]

.....
I've already advised the owner (who is a builder by the way) that oak isn't a great choice but he's replacing an existing one and prefers like for like.

OK..I'll bite.

Why not ?

Lots of houses round our way have oak windows.

I chose to ignore the comment Roger :lol: I've made hundreds of them over the years and never had an issue. Got around 15+ in the workshop,nearly ready to go out at the moment. Very knowledgeable guy Jacob, but I do wonder about some of the things he posts.

Side topic, have you disabled pm's ? I tried messaging you a week or so ago but couldn't see the option.
Cheers
Coley

Sent from my SM-G900F using Tapatalk

 

[Jacob]

.....
I've already advised the owner (who is a builder by the way) that oak isn't a great choice but he's replacing an existing one and prefers like for like.

OK..I'll bite.

Why not ?

Lots of houses round our way have oak windows.

Surprisingly not durable as a window unless impregnated with preservative and only using stainless or brass screws/ fittings (acidity - tannic acid). Doesn't hold paint very well.
I've removed lots of old windows in the past and the redwood pulley stiles, jambs, etc would be in good nick and only the oak cills rotted away, having lost all their paint

 

[RobinBHM]

I've removed lots of old windows in the past and the redwood pulley stiles, jambs, etc would be in good nick and only the oak cills rotted away, having lost all their paint

Wouldnt that be because a cill is the horizontal part of a window and there most inclined to be savaged by rain and sun?

Also many windows that were set directly on stone cill with no drip overhang. Water collects and the cill rots. A very common
Problem with box sash windows.

The high tannin / extractives content gives oak a high durability, for the same reason as cedar, iroko etc.

 

[Phil Pascoe]

A friend years ago was taken to court for replacing windows with uPVC in a building in a conservation area and was told to replace them with oak, as they would supposedly have been. (He did appeal successfully.) He replied that he had been a professional decorator for 20+ years, and had never even seen an oak window. I'm 63, and I can't ever recall seeing one. As Jacob said - besides anything else, it doesn't take paint very well.

 

[RobinBHM]

Theres no point using oak if the window is being painted. The course ring porous grain of doesnt make for good painted finish anyway.

Oak is weak in shear and is prone to surface checking, another reason for not painting.

It is still a very durable timver however.

For a window with a paint finish there are better timbers, iroko, accoya, Douglas fir.

 

[thick_mike]

I think people get the idea that oak is a premium wood and everything else is worse idea stuck in their heads.

 

[RogerS]

.....
I've already advised the owner (who is a builder by the way) that oak isn't a great choice but he's replacing an existing one and prefers like for like.

OK..I'll bite.

Why not ?

Lots of houses round our way have oak windows...... Doesn't hold paint very well.
.....

Not even linseed oil ? :wink:

 

[Jacob]

...

OK..I'll bite.

Why not ?

Lots of houses round our way have oak windows...... Doesn't hold paint very well.
.....

Not even linseed oil ? :wink:

Dunno. Life's too short I'll probably never know!

 

[Phil Pascoe]

My neighbour owned his own joinery for years and then took the easy money and became a college lecturer - he always rated idigbo for windows. My mother had all her joinery (windows, floors, skirting, doors, stairs, everything) done in iroko - the main problem was with the meeting rails. If they bowed together they clashed when the window was closed or even prevented the windows closing properly, if in opposite directions they let in the wind (and west facing, two miles from the north Cornish coast that was not good. All the large section stuff was stable, though.