• We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Box sash windows

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

Manny

Established Member
Joined
31 Mar 2004
Messages
152
Reaction score
0
Location
London
Hi
I'm going to be making a box sash window, frame and casements. Now I've built these before but it was a long long time ago and since then building regs. etc. have changed.
I'm after any advice but particularly regarding weather and draught proofing as well as suppliers of draught proofing strips specifically for sliding sashes.
Thanks
 

Steve Maskery

Established Member
Joined
26 Apr 2004
Messages
11,799
Reaction score
144
Location
Kirkby-in-Ashfield
Hi Manny
Never made one, but...
I remember someone, somewhere, long ago and far away pointing out that in his experience the first part of a vertical sliding sah window to rot is the bottom of the front retaining piece. It probably has a proper name, but it guides the upper sash in its travels.

This is because water collects behind it and cannot run away.

So this guy's advice was to cut away this part of the flange for a couple of inches, so that when water runs down, it can also run out.. He reckoned his windows never rotted in this way (although he didn't specify in what ways they DID rot...)

HTH
Steve
 

Manny

Established Member
Joined
31 Mar 2004
Messages
152
Reaction score
0
Location
London
Thanks Steve
Sounds like it could be the parting bead that seperates the top and bottom sash. The rot that I've repaired in the past has come in from the sill at the sides.
 
A

Anonymous

Guest
since then building regs. etc. have changed.
It's the U-values (2.0 W/m2K) that you should be concerning yourself with, and a single glazed window does not meet it by a long shot. I have had to get a relaxation order for mine and I am going to build interior shutters. Although, if it is not a new build, I don't think there is anything they can do in the case of a replacement.

You also need to be very careful blocking all the slight draughts, because they are what stop the condensation building up on the interior of the panes. Especially at the meeting rail. Even though the planning won't like it. But if you do block off all the natural ventilation and let condensation build up, over a period of time it will rot the astragals

It probably has a proper name, but it guides the upper sash in its travels.
It is called: 'The outside lining' the piece that seperates the sashes is called a 'parting bead'.

usually you can just get a small rat-tail file and file a small round channel at the bottom back of the outside lining which will pick up the water run off and divert it onto the cill.
 
Top