# Traditional Casement Window



## softtop (7 Sep 2010)

I have to make six windows for my house. Four are replacements, two are new but all are a similar style. There is only one original one left (completely rotten) but I am trying to copy it as closely as possible.

This leads to a selection of new techniques for me but I hope you may be interested to see how I've been getting on.

The timber is all Dougie Fir (over 0.5 cubic metres of it) plus oak for the cills.

The original window frame has open mortice/tenons with pegs and the window has through tenons (with shoulders), also pegged, plus wedges on the top and bottom of the glazing bars. Hence this is what I'm trying to do. (Can't promise not to get the Domino out for the other ones though!).

Any comments gratefully received.

First of all I have the oak for the cill:







...which I plane two sides straight on the P/T:





...then cut the profile on the bandsaw:





...then over to the router table to get the flat section for the window to sit on:





Finally I route a drip groove in the bottom.

I spent the whole bank holiday weekend cutting, planing, thicknessing and then putting mouldings onto a load of timber for the windows:





...and making glazing bars:






So I cut a mortice in the cill and tenon onto the frame:





I bought a mortice machine from the bay which I reckoned was a bit of a luxury purchase, but having tried cutting them by hand it took me ages and the results were somewhat rough so I'm pleased I did so. I've been sawing the tenons on the bandsaw, which has worked quite well.

Next I make some dowels out of oak:





...and cut the holes in the mortice and tenons, remembering to move the holes in the tenon 1.5mm out to allow the dowel to pull the joint tight:





I am greatly indebted to the video on Youtube from Chris Schwarz showing how to do the drawbore stuff.

Next I glue up and bash in the pegs and then clamp for good measure:






This particular window has an additional timber support on the top (complete with drip) which I have slotted onto the protruding tenons:






Now onto the window frame. I've forgotten to take a photo but I've cut out the mortice and tenons on the top and side rails. Now I need to add in the glazing bars, so more morticing and then shaping the rails to fit:





...and they do:





Dry fit to work out where the middle glazing bars will go:





I cut them out to fit as well (tricky business getting them to meet up in the middle!) and then make some more oak pegs and drill out the mortices:





... and tenons:





...before putting it all together with the glue, bashing in the pegs, checking it's square and clamping up:





Here is a pegged joint:





...and finally adding the wedges in to the top and bottom of the middle glazing bar:






Don't know if a lot of this is overkill, and I could certainly have done it a lot faster without so many traditional techniques. Also there are a few rough edges but it will all be getting painted so noone will ever know...

Now I need to consider how I will do the next five.

Thanks for looking,

Henry


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## CroppyBoy1798 (7 Sep 2010)

I shalt insult you by commenting on your work, I neither know about windows or have ever tried to make any, but, from what I see in the pics it looks excellent!

What caught my eye however was the bandsaw! Is it a BS300E? Looks pretty clean and new anyway, I got the mentioned model myself a couple of weeks back, havent put it to proper use yet but I'm pretty pleased with it. How are you finding yours?


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## Dibs-h (7 Sep 2010)

Very impressive work I must say - I ended up taking the short way round and getting a domino. :lol:


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## Chems (7 Sep 2010)

I know its to late but I was talking to a joiner friend the other day and he said that through mortices on windows are just a path for the water to get into the joint. Makes sense I guess.


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## OPJ (7 Sep 2010)

Chems":3v5ahwlj said:


> I know its to late but I was talking to a joiner friend the other day and he said that through mortices on windows are just a path for the water to get into the joint. Makes sense I guess.



I've always felt the same way about doors, gates and anything else that's exposed to the elements. With windows though, I think the risk is 'minimalised' since any exposed end-grain on the tenons is concealed within the surrounding frame opening.

Nice job so far.


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## softtop (8 Sep 2010)

Thanks for your comments.

The bandsaw is a BS350 and I've been very impressed with it (once I had put on one of Ian's blades). It's taken everything I've thrown at it without complaint. The only tiny niggle is that the table has a bit of movement front to back, which is not adjustable. Generally not an issue though.

As regards the through mortices they are on all the windows in our house. Most of them are original, 250 years old and still going strong. I guess for sashes (where they are not even painted at the sides) there is more protection from the frame but in the case of the casements they are more exposed.

I am no expert but why would this method of construction have been so popular for so long if it was fundamentally flawed? Clearly they could have made them with the mortices not going all the way through? Maybe I'll give the SPAB a call...

Henry


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## joiner_sim (8 Sep 2010)

Hi,

I like the look of your traditional techniques! I haven't made a window frame now since Feb, and its good to see one being made on the forum.


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## JonnyD (8 Sep 2010)

Its looking good but why is there a flat on the sill. This has the potential for water to sit on the cill under the casement wheras if it were a full slope the water would run off.

cheers

jon


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## softtop (9 Sep 2010)

Jon - good point. I had just blindly copied what was there.

Do you think I should put a slope on? Is this normal practice for casements?

Thanks,

Henry


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## joiner_sim (9 Sep 2010)

On a traditional casement window, the window sill rebate should really be bevelled as well as the outer part of the sill. I used to put a 5 degree bevel on the rebate and a 5 degree bevel on the bottom rail of the casement for a nice tight fit.

Sometimes the bevel would have been done at 9 degrees when required.


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## Chems (10 Sep 2010)

softtop":14mbfq51 said:


> I am no expert but why would this method of construction have been so popular for so long if it was fundamentally flawed? Clearly they could have made them with the mortices not going all the way through? Maybe I'll give the SPAB a call...



I've no idea either, don't forget to route a bead/channel on the bottom of the sill so the water drips of their and doesn't make it any further back.

Regardless of technique differences they are beautiful windows and that's some fine craftsmanship you've put into them.


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## softtop (10 Sep 2010)

Thank you Chems for your kind words and don't worry I have put a drip channel into the cill.

I am certainly considering bevelling the cill/bottom rail now.

For those of you interested in the open mortice question I have had a chat with SPAB who put me on to Charles Brooking, an avid collector of architectural salvage and information. He runs a museum (http://www.thebrookingcollection.com/) and is incredibly knowledgeable about such things.

He said that given the relatively slender proportions of the windows and the weight of the glass, plus the fact that the glues of the time were not that potent, you wanted to have the maximum strength and stability in the frame as possible, and despite the problems with through mortices a stub tenon would not provide anything like as much strength. 

I guess there may be counter arguments today, given advances in technology, but definitely interesting to hear his take.

Cheers,

Henry


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## P3t3rT (15 Aug 2012)

Congratulations this is a great article. The only problem for me is that I am looking for advice on making and jointing glazing bars. Has anyone got any simple methods please?


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## Teckel (15 Aug 2012)

I've done a lot of joinery for new and old and never did a stub tenon on anything. As was said already a through mortice with wedges is a very very strong joint. On all the old style joinery I've seen there has been little or no water damage to that area of the joint.


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## AndyT (15 Aug 2012)

Really glad to see timber windows being made. It's encouraging for anyone else whose house might need some repairs. I agree that following original construction is the best guide. What's interesting though is that if these were being entirely hand made (using hand planes for the sections) you would start by marking out the timber all in square sections, cut the M+Ts and then plane the rebates and mouldings. 
What you have done is a hybrid between machine and hand methods. Don't take that the wrong way - I am properly pleased that you have shown that it works. I guess it's the approach one would have to use if buying the sections ready machined.

As for P3t3rT's question on techniques for making and joining moulding bars, this is a huge topic in itself, with trad methods intimately linked to different designs of moulding planes and different local approaches in UK, US and continental Europe. But for an entertaining intro you could try a couple of Roy Underhill's videos - 

Start here http://www.pbs.org/woodwrightsshop/video/3100/index.html and scroll down for the "Simple Sash" episode; also go back to the 2009-10 season and have a look at the Corner Cupboard episodes.


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## Wouldchuk (16 Aug 2012)

Did you use a dedicated router cutter set for the mouldings - the glazing bars etc - and if so, may I ask the details?

Looks to be a top job so I'd be interested in your continuing on - even if you change to the Domino.


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## softtop (16 Aug 2012)

I bought a narrow sash ovolo cutter from Wealdon Tool Co - Part no T1352-1/2, which I put in my router table, then ran the glazing bars and rail/stile pieces over that to form the moulding. The other side (for the glass) is just a rabbet. Was trying to match them to some 200 year old windows and that was the nearest cutter I could find. I didn't get a reverse one for making the joins as I just cut those on the bandsaw to fit.

I did make the rest of the windows with M&Ts in the end but didn't bother with the drawboring. No photos but the process was very similar. Now all fitted and painted and doing the job!

Cheers,

Henry


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## Bradshaw Joinery (18 Aug 2012)

bevels or 'weathering' is classed as a surface of 9 degrees or more, ive seen plenty of old windows that havent rotted with a flat under the casement, and plenty that have with bevels..... it depends on the wood and how well there sealed i think.


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## Jacob (18 Aug 2012)

softtop":2iqxwmjh said:


> ....
> 
> I did make the rest of the windows with M&Ts in the end but didn't bother with the drawboring. ....


Quite right too. 
Drawboring is a bit of a fashion nowadays but was traditionally confined to use only where necessary - usually where clamping is difficult. The most common example being the joint between a stair string and a newel post, where clamping is impossible.
On windows like yours the peg holes are drilled straight through _after_ the frame or the light has been made up. Very often the peg would have been square - just split from an off cut, but by the time it has been hammered through a round hole it will lose nearly all it's shape, with just a trace of the square section left.

Look good BTW. If you stick to exact copying you can't go far wrong.


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## adzeman (18 Aug 2012)

If you follow the same method as the originals you will be OK Straight through mortice and tenons are fine as the the timber dries out and expands at the same rate including the wedges and the draw dowels. It never fails to amaze me when working on some of the old buildings in London just how well made the windows are, but most of all the quality of the timber and he closeness of the growth rings This timber was slow grown and air dried which is why our window specialist used reclaimed demolition timber mainly from demolished churches. I was responsible for the refurbishment of the Royal Society Building which prior to them purchasing it over 200 years ago and was built by John Adams and where he lived. One of the things I noticed was the difference in quality of the joinery below stairs. Doors were still panelled but no mouldings, simple skirtings again no mouldings, shelves but jointed and hand made nails. When we took up the floors we found a significant number of finds in the dirt and debry all collected by the Society. We discovered a tunnel under one floor which was more like a cobbled street which went down to the River Thames which is how the wine was brought in. I digress. Carry on as you are doing and if you can try and purchase some reclaimed softwood its a treat to work.


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