Box sash windows

[Jim mcgrath]

Does anyone know where I could find a book or dvd on how to construct box sash windows. There doesn’t seem to be much info on the internet.
I saw a sliding window the other day, that uses springs instead of weights. I would settle for a book on how to make these if that’s all that is available.
Thanks.

 

[Jacob]

Does anyone know where I could find a book or dvd on how to construct box sash windows. There doesn’t seem to be much info on the internet.
I saw a sliding window the other day, that uses springs instead of weights. I would settle for a book on how to make these if that’s all that is available.
Thanks.

SPAB is one source of info. https://www.spab.org.uk/
and the Scottish equivalent https://www.shbt.org.uk/
Old joinery books are good; best is "Building Construction" W B Mckay
Best source of all is to take out a window and pull it apart to see how it's done.

​

 

[Ollie78]

Do not use the spiral balances.
There is some reference in modern practical joinery by Ellis.
The constriction is actually fairly simple and varies in detail by period and region.
As said above , copy an existing one.

 

[niall Y]

I would echo @Jacob and say W B McKay The section on Joinery is available as a separate book. The relevant bit is Chapter 10, on Cased Frame Windows.

 

[Doug71]

Bradshaw Joinery did a full series on making one, I haven't watched it but he knows his stuff and generally gives good advice.

 

[johnnyb]

I echo Jacob but suggest window and doormaking republished by lost art press. Why do you fancy learning to make one? This may help to pinpoint what's Best.

 

[Jim mcgrath]

The old house where I have a hobby workshop has a couple of box sash windows, hence my interest. I was going to take apart one of these as it is badly damaged anyway.
The house was built in 1880 odd. Is it likely that glue would have been used in the construction of these windows?

 

[niall Y]

Wedges and hide glue on the sliding sashes. but the boxes would just have been nailed with wedges into the sill. However, stiffening blocks would have been glued in position, to reinforce the top of the box frame.

 

[meccarroll]

There are tons of videos on utube about box sash windows. I have some off-cut sections pinned together from when I made some sliding sash windows:

Below shows the general layout and construction details. Generally they will be made from 20-22mm PSE (Planed Sides and Edges) softwood timber. If you take a look at the left that is the outer section and forms a lip to hold the sash in, then you have a middle section that has a groove to take parting bead, the sashes sit either side and finally the inner box section where you pin a piece of staff bead to hold the inner sash in once all of the sashes have been fit. So quite a simple construction really.


Ignore the piece of wood between it's just there to hold the sections together, the void is where the weights pass up and down and would be separated by a slip of ply or thin pece of softwood (to stop the weights from getting tangled up).

The cill is quite staightfoward just two slopes and a flat on the inner side where the staff bead is pinned.

The box sections are usually cut through the cill to the bottom of the cill and either pinned or screwed to the cill. the old way would be to cut out a groove in the cill and house the middle section in the cill but that always formed a rot spot so I just cut and scribe mine over the cill which has worked well for years.

You can put a mould on the front section (which I do) but it's not needed just makes the box look pretty.

Hope this helps to get you started.

 

[johnnyb]

Here's a few snaps of a frame me and 1275gt put together. It uses more traditional joints and nailed on front/back which is very common.

 

[johnnyb]

Sorry the last pic is something else altogether.

 

[johnnyb]

This also shows the pulleys and the weight pocket(later internal style)

 

[Cooper]

What a brilliant thread this is!!
It's brought back so many memories of renovating our 1880s house and the McKay illustrations are beautiful.
So much better than reading about polititions clothes and the failings of the police.
You have really cheered me up this morning.

 

[Fitzroy]

The box sections are usually cut through the cill to the bottom of the cill and either pinned or screwed to the cill. the old way would be to cut out a groove in the cill and house the middle section in the cill but that always formed a rot spot so I just cut and scribe mine over the cill which has worked well for years.

I've been thinking that this creates a rot pocket for a while, however I'm confused by the alternate you are suggesting. How is the pulley stile affixed to the cill?

 

[Jacob]

I've been thinking that this creates a rot pocket for a while, however I'm confused by the alternate you are suggesting. How is the pulley stile affixed to the cill?

it shows you in the drawings above from WB McKay. A housing and a wedge. This is how it is always done. There isn't another way. Rot is down to poor maintenance and it is always going to hit the lower end of things first, the cill, then the lower end of stiles and linings, then bottom rails etc
McKays drawings are of their time and fairly high spec in some ways - in the field shortcuts are found. Most common is to have the stile not tongued into housings in the linings as shown, but just butted up, glued and nailed. Looks a cheapo but seems to last! If retro-fitting a sash this make the job much easier as it can be fitted without the inside linings in place, then fitted afterwards.

 

[meccarroll]

I've been thinking that this creates a rot pocket for a while, however I'm confused by the alternate you are suggesting. How is the pulley stile affixed to the cill?

The reason I scribe the pully stile over the cill is because all of the sliding sash windows I have ever repaired over 40+ years have always rotted at the spot where the pully stile is traditionally fit into a groove in the cill. IT'S NOT A GOOD DESIGN.

If you scribe the pully stile over the cill you do not create a deep pocket for the water to fill and so rot the cill. I usually screw up from under the cill into the pully stile. I drill a pilot hole then squirt some silicone in then screw up and the job is a good one.

Don't forget that the pully stile is traditionally only about 100mm wide and is also fixed either side by the inner and outer stiles too.

One of my main jobs as an apprentice was to go out and repair sliding sash windows, two a day was considered the norm. When you see that every window has rotted at the joint where the pully stile is notched into the cill you would have to be completly stupid to re-build a rotten cill in the same way so we used to cut in a new cill and notch the front and rear side stiles but scribe the pully stile over the cill and pin down through the side of the pully stile.

Try making a mock box section around a small section of cill and see what you think.

 

[Jacob]

....

.... I drill a pilot hole then squirt some silicone in then screw up and the job is a good one.

Won't know if it's a good one until it's seen a hundred years or so, which many of the old ones definitely have!

Don't forget that the pully stile is traditionally only about 100mm wide and is also fixed either side by the inner and outer stiles too.

More a case of stiles fixed solidly to housings in head and cill, making up a frame. Then linings fitted to stile, cill and head.

One of my main jobs as an apprentice was to go out and repair sliding sash windows, two a day was considered the norm. When you see that every window has rotted at the joint where the pully stile is notched into the cill you would have to be completly stupid to re-build a rotten cill in the same way so we used to cut in a new cill and notch the front and rear side stiles but scribe over the pully stile over the cill and pin down through the side of the pully stile.

Try making a mock box section around a small section of cill and see what you think.

I've done hundreds - more often replicating them with new work, always copying exactly, as close as possible. True that rot is always at the lower ends - this is because water runs downhill, and anyway the top of a window is always well under cover.

 

[johnnyb]

I'm with Jacob on this one. But to each there own. I just prefer a solid square frame. People also leave a gap on the front linings to stop rot. But maintenance and tightly made joints are best. The biggest issue imho is the incompatibility of plastic/ caulk sealers especially sealing the bottom of cill/front linings. Try and use putty if you must at least it allows breathing(when it cracks) the caulk sealants simply seal to well and waterlog the whole thing.

 

[meccarroll]

Won't know if it's a good one until it's seen a hundred years or so, which many of the old ones definitely have!

I'm happy with my fixing method. Yes it's true I won't know in a hundred years time because I doubt I'll last a hundred years but many of the windows I had to repair had not lasted 100 years.

More a case of stiles fixed solidly to housings in head and cill, making up a frame. Then linings fitted to stile, cill and head.

Not at all Jason the inner and outer stiles are fixed to the cill and hold the box frame in position the wedge is simply knocked into position to tighten things up first and once the framework and wedge starts to shrink in goes the water and rot occurs.

I've done hundreds - more often replicating them with new work, always copying exactly, as close as possible.

I repaired hundreds of sliding sash windows because they were all made with a housed pully stile creating a rot zone in the housing. And that's why I do not house the pully stile.

I have got to admit I did initially ponder making the Box frames with a traditional wedge and groove and do understand why is was done this way but after repairing about 150 or so box sashes and all with the same problem I diecided against it.

The cill area around the pully is the main weak spot on a traditionally made box frame.

I think we will just have to disagree on this one Jason.

 

[johnnyb]

It's not that it's a bad idea it's just not how it was done. If it was proof against it ever rotting I would consider it but after 100+ years these windows can basically turn so dry and twisted water can penetrate In a multitude of spots. Making them with a housing is my favourite bit oddly it's just a rock solid joint with the sizes set by the inside of both housings.