Sash Windows Removing Dividers ?

[rideforever]

I've got some sashes that have two panes and I'm thinking of getting slim double glazed units and re routing the sashes and sticking in the double glazing - mostly for noise purposes.
But because they have two panes I am wondering if I can just cut the divider out so its a single pane ?
Is the divider structural ?
This photo shows the type:

 

[mrrusty]

it's not structural, but you would be better leaving them as single pane and perhaps adding secondary glazing. Sash windows that just have DGU added no longer work properly because you double the weight of the glass (or more, because many old box sashes only had 3mm glass in) and the balance weights no longer balance.


Also, the rebates are really not big enough for DGU, even 4-4-4 and that is hardly worth doing. The best glass for converting traditional sashes is vacuum DGU but very expensive. https://www.vacuumglazing.co.uk/

 

[rideforever]

@mrrusty
thanks ... 4-4-4 ... means 8mm of glass right, which is a lot more than 3mm ... what about if I go for a 6mm acoustic pane ?
no double glazing ....
because float glass is almost see through acoustically and maybe that would be enough
as for sash weights, my neighbours have had double glazing installed so I guess it's possible - I could also use square weights.
i don't know if new double glazed sash windows have larger bores for the weights to pass in ?

 

[mrrusty]

Apart from the weight problem, the profile of the sash as originally constructed only has a rebate suitable for a single pane of glass without spacer bar. You can try machining the rebate to get a bit more space, but I've seen some bodges....

You can make new sliding sashes with bigger rebates, and add weights to the original boxes, but the size of the weight boxes may not allow wide additional weights, and if you make them taller you lose opening ability. And, by the time you've made new sashes and mucked around with the weights, you might as well have new windows designed for DGU in the first place.

Fitting DGU to original single pane box sash windows is IMHO a bodge that doesn't work properly. You could use 6mm glass, but you will still be increasing the weight.

 

[endecotp]

I've got some sashes that have two panes and I'm thinking of getting slim double glazed units and re routing the sashes and sticking in the double glazing - mostly for noise purposes.

Don’t expect a huge improvement.

But because they have two panes I am wondering if I can just cut the divider out so its a single pane ?

The divider is called an “astragal”.

In principle you can remove them. But is it a listed building or in a conservation area?

Is the divider structural ?

No.

Sometimes the issue with the counterweights is addressed by replacing the steel weights with similarly-sized lead weights.

I have sash windows with 6-over-6 panes. I’ve installed secondary glazing on the east-facing bedroom windows. At some point (£££££) I will deal with the larger living room windows, where secondary glazing would not be appropriate. (I have a thread about the living room in “Projects”.) Vacuum units is a possibility (subject to ££££££). I would not consider removing the astragals, though you may have different views depending on e.g. whether the windows are all uniform or not.

 

[rideforever]

@endecotp
I just had a look at some made to measure two pane secondary glazing ... about £640 for one window. They even have something called "tilt in".
Is that easy enough to do, diy ?

 

[endecotp]

@endecotp
I just had a look at some made to measure two pane secondary glazing ... about £640 for one window. They even have something called "tilt in".
Is that easy enough to do, diy ?

I found it difficult to find a supplier who would supply units for DIY installation at a sensible price. But that depends on where you are.

It's not particularly difficult to install DIY though it helps to have a competent second pair of hands. Larger windows are of course more difficult. What are your window reveals made of?

There are different styles. Think carefully about whether a sash or a single window side-hinged would be better. How often do you actually open this window?