Transomed & mullioned sash windows.

[ElectronicFur]

From the other post on sash window restoration costs:

You remove the staff beads first, which are - when looking from inside the room - the strips of wood around the inside of the sash box frame that hold the bottom sash in place. After that you can take the bottom sash out into the room. Then you remove the parting bead, which as the name implies keeps the 2 sashes apart, and the top sash comes out, again it comes out into the room. All that work has to be done from the inside anyway. The sashes can then be taken away and restored anywhere - the box frame can be cleaned up from the inside, it's really only at this stage that having external access is useful at all, as you strip the paint off the outside face of the sash box - but this isn't much and you can do it easily enough by leaning through from the inside.

Any ideas what the difference are when the sash windows are transom and mullion ones?

All my sash windows have transoms and mullions. I need to restore them all at some point. Some have unfortunately been painted shut, some with big gaps, so very draughty.

Window example here:

Also does anyone have any idea why this bay has pulley wheels above the sash windows? In the photo you can see two of the brass pulley wheels that are above the windows, no idea what they would have been used for. It's only this particular bay that has these above the windows.

 

[Feltwell]

I've not come across that style of sash before. Looks like the only difference is the bottom sash has to pass behind what is a purely decorative transom. I'm presuming that, as pictured, the bottom sash continues up behind the transom and stops at the top of the transom?

You've still got staff beads at the bottom, take those out and the bottom sash should have enough movement to come out, they're never that tight (or they wouldn't work!). From the look of the top you've then got parting beads as usual.

The wide blade at the end of this type of pry bar is invaluable for tapping around the paint line to break it, I've found - much better than the "period" method of a blunt chisel, the curve in the shaft helps no end!

https://www.screwfix.com/p/magnusson-pry-bar-8/8640v

Another top tip - when the bottom sash is out, don't do what so many people do and try to lever out the sash pocket cover, it just damages the edge. Break the paint line round the edge, then drive a screw partially in about 1" in from the bottom edge into the groove where the parting bead goes, then hook a pry bar (bigger than the little one above) over that, braced against a bit of scrap wood on the surrounding frame, and gently lever the bottom of the cover out. They nearly always come out bottom first, the top is usually shaped to hook them in.

The extra sash pulleys at the top? My guess was some long defunct homemade roman blind system, thinking does the sun shine in that window such that you'd want to lower some sort of sun shade? But that wouldn't work would it - as the back of the cord disappears into the sash box, unless they counterbalanced a roman blind with a small weight?? Hopefully someone else will have a better idea!

A handsome window by the way, very nice, as are the trees in the garden beyond.

 

[ElectronicFur]

I've not come across that style of sash before. Looks like the only difference is the bottom sash has to pass behind what is a purely decorative transom. I'm presuming that, as pictured, the bottom sash continues up behind the transom and stops at the top of the transom?

You've still got staff beads at the bottom, take those out and the bottom sash should have enough movement to come out, they're never that tight (or they wouldn't work!). From the look of the top you've then got parting beads as usual.

Yes the bottom sash stops at the top of the transom. I thought it might be difficult to get the bottom sash out. Because the inside transom is there, then the top of the bottom sash, then the bottom of the top sash, and then the outside transom is there as well. So not sure if there is enough movement.

Thanks for the tips, I was wondering how people got the sash pocket covers out without damaging them.

I actually have one bay where the back of the pockets are exposed when the shutters are shut, due to some missing woodwork. But the odd thing I noticed there, is that there is only one sash weight in the pocket. The weight has a pulley on it, and the cord goes round it, so it is used by both sashes. Is that a common arrangement?

 

[Feltwell]

But the odd thing I noticed there, is that there is only one sash weight in the pocket. The weight has a pulley on it, and the cord goes round it, so it is used by both sashes. Is that a common arrangement?

I suspect you're just missing a sash weight - or is just at the top of the sash box? I can't see how a single weight could possible be used by both sashes.

When the windows are shut, the weight for the top sash is at the bottom of the sash box, but the weight for the bottom sash is at the top of the sash box.

 

[ElectronicFur]

When the windows are shut, the weight for the top sash is at the bottom of the sash box, but the weight for the bottom sash is at the top of the sash box.

That's what I thought until I saw this...

 

[Feltwell]

That's a new one on me - but I can see how that would work. Seems a bit needlessly complicated though, and more expensive having to have the special weight with a pulley on the top - but, no need for "feathers" (a free-floating strip of thin timber to keep the weights apart) and no danger of the weights hanging up, where they catch on each other.

 

[Feltwell]

Seems that whilst uncommon it's not unique - Reddiseals do a kit to add a pulley to the top of their lead weights:-

https://www.reddiseals.com/product/sash-lead-pulley/

One distinct advantage that's occurred to me is the sash box doesn't need to be as large as it is with 2 separate weights.

 

[ElectronicFur]

Thanks, was looking on their site last week, but hadn't seen those.

 

[CliffordPope]

One distinct advantage that's occurred to me is the sash box doesn't need to be as large as it is with 2 separate weights.

But the weight would have to be twice as big if it balances two sashes?

On the extra pulley question, I do know of a window where the weights for the inner window hang in an enlarged outer sash box, the cords being taken across the top of the two outer sashes through an additional pair of pulleys.

 

[Feltwell]

But the weight would have to be twice as big if it balances two sashes?

It would need to be the same total weight, but you wouldn't need the clearance space that 2 separate weights require to pass each other - I think you could get away with a smaller sash box.

 

[ElectronicFur]

On the extra pulley question, I do know of a window where the weights for the inner window hang in an enlarged outer sash box, the cords being taken across the top of the two outer sashes through an additional pair of pulleys.

In my case the window weights are in the usual sash boxes, so these pulleys were for something else I think.