# Box sash windows, which is correct construction.....



## RobinBHM (17 Sep 2020)

I know traditionally the chill is grooved out for the pulley stile and in fact the groove was tapered for wedging.....all fine.

But what happens with the inner and outer facings.

I've seen some drawings show both inner and outer run through to the bottom of the cill

In others I've seen the outer facing stop at the top of the cill.



Also some show the outer facing cut back a bit to allow water out, others don't.



So what do you guys do?


----------



## owen (17 Sep 2020)

I run both inner and outer through the cill, but if there is a beading on the outside face I stop that on top of the cill. That's using accoya though so no real worries about water ingress


----------



## johnnyb (17 Sep 2020)

the last traditional one I did the facings came over the front of the cill. the cill was relatively short compared to a casement window.


----------



## RobinBHM (17 Sep 2020)

Many thanks for your answers, I was thinking structurally it makes sense to run them through, then there is a big gluing and screwing area

stopping the outer facing at the cill seems to me to be putting a butt joint just at water ingress level.

Im still in 2 minds whether to do a scallop out of the outer facing of 15mm so there isnt a pocket where water can sit -but Im not sure Ive seen that on original box sashes.


----------



## johnnyb (17 Sep 2020)

have a look.


----------



## Ollie78 (24 Sep 2020)

Hi

In most cases I run the inner and outer cheek straight down, sometimes I do it where the part that is sticking out is notched and angled so it goes on top of the cill kind of like a masons mitre but square. Some other times I will cut stopped rebate about half way down the cill.
In most situations it is a case of copying what is there to please the listed building chaps. Lots of regional and period variations too.

A good way to keep everything nice and solid is to rebate the pulley lining into the inner and outer cheeks I normally do half the thickness of the liner, so about a 10mm by 10mm groove with a 10mm tongue on the liner, this will make it very solid and keep it square, the outer cheek head is normally a masons miter as well.

Don`t forget to put the wagtails in before installing the window !!

Personally I don`t like the scallop, you often find people (probably painters) do it after the rot has started there and they just cut off the rotten bit and paint it up. 
I think the key to longevity is using good quality timber and good quality paint.
It is very often the case that in a house the original windows are in better condition than the ones from the 90s that were made of rubbish wood with rubbish paint.

From your picture it looks like they go straight down, it looks like the cill is shallow too, is there an over capping or secondary cill in front of it or is it painted stone? can`t tell. If its timber I would have a good close look at it. 

Ollie


----------

