draughtproofing sash windows

[andyv]

I'm about to repair a sash window with some rot along the bottom of the top sash. This will entail removing the staff and parting beadings, and whilst out I'd like to apply draughtproofing. I see various companies supply kits which consist of new beading with built in brushes to stop the draught.

There are various methods of advancing complexity and cost. The most economical would I think be to rout a groove myself into the beading and apply the carrier and brush. If my beading is OK I could do the whole house this way for about =A375 whereas buying kits would be =A3900.

Has anybody tried this?

If so which of the beading is the brush applied to, and what's the best way to seal the bottom edge of the lower sash?

[NT]

Assuming you mean brush in slot, the brush goes into a slot in the sides of the sliding sashes themselves.

NT

[andyv]

That's one way, but the DIY kits seem to fit it in the beading.

I've seen one professional version, the belt and braces method, which has two lines of brushes on the ends of the sash, one in the staff bead and one in the parting bead. That's 4 brushes each side of each sash, but these are =A3100's per window. I'm hoping that a single line of brush will give a worthwhile improvement though.

[stuart noble]

The Brush Pile Parting Bead looks interesting. If you can get that to stay in the groove without fixings it looks like the best bet. The problem with having brushes everywhere is getting the sashes to move freely

[NT]

Yes. Sliding sashes are fussy about adjustment, and brushes only makes them more so.

FWIW there's an alternative to brushes, its jsut a very thin folded strip of plastic sheet, less than 1mm thick, that fits in a slot and presses itself gently against the wood. No issues with stiff operation, it seems to last well, and does the job better than brushes. I've not seen it on sale, I presume its very cheap, there's little to it and I'm sure it would be easy to make your own, given the right type of plastic - which one though I've no idea.

NT

[Terry Casey]

I had some of that many years ago and it worked very well on the doors I put it on. Unfortunately, it has now hardened and some of it is cracked, so I really need to replace it.

The only problem is that the roll I had is the only one I've ever seen - and that was being sold off cheap in a sale!

Mine didn't fit in a slot though - you simply pinned onto one surface before folding it into a vee shape.

It worked very well on the doors but I never thought of putting it on the sash windows we had then - it would have done an excellent job!

It seems like an excellent product that never caught on, which is a pity.

The problem with making your own would be the hinge bit down the middle (which is where mine has broken after about 20 years).

Before folding, this part of it bears a marked similarity to the folds in light cardboard boxes (like cereal packets) when you flatten them out.

[stuart noble]

The folding plastic thing didn't work for me. One winter under compression and they were as flat as a pancake. I think you'd need silicone to retain springiness, possibly with a pvc skin for smooth running

[NT]

I dont thinkyre meant to be squashed flat in use

NT

[Roger Mills]

I've replaced the staff and parting beads on mine with new beading with brushes already built in. You *may* be able to route suitable grooves into existing beads and just buy the brushes and carriers - but you'd be lucky to remove the old beads non-destructively, and they'd probably be pretty brittle anyway - so might break whilst being machined or re-fitted.

I got my stuff from

- using primed staff and parting beads with the brushes already fitted.

The bottom of the lower sash was sealed simply by the brushes on the bottom (horizontal) staff bead.

Contrary to what some people have said, I found the the sashes actually slid more smoothly against the brushes than they previously did with just paint to paint contact. Besides reducing (not totally eliminating) the drafts, traffic noise was also reduced.

[andyv]

Ah good somebody who's done it. Thanks Roger. There are two things I'm puzzled about. With the inner staff bead do you fit it with brush all the way up to the top, even the part where the sash only goes when it's open or do you splice in a section of beading with no brush?

Similarly with the parting bead, you will need brush facing one way for the bottom and the other way at the top. Do you splice two sections together facing different ways?

Actually a third thing. It seems there is a double barrier on the lower sash but only a single on the upper because you can't refit the outer bead as it's part of the box frame. Does this matter?

[stuart noble]

It's always going to be squashed flat somewhere. If it loses its spring it's no use

[Roger Mills]

I did fit mine all the way to the top because it looks better and there's no joint for anything to get caught on, but I suppose you

*could* splice in just the bottom section if you wanted to save money.

Th brush faces outwards in order to seal the top sash when closed. The bottom sash is sealed with the staff bead.

No there isn't. There's a single seal on each - provided by the staff bead on the lower sash and the parting bead on the upper one.

They only need sealing when closed. When open, you're going to get a howling gale anyway!

[andyv]

Ah it's beginning to make sense now. So the only bit that I'm not sure about is where the the two sashes join in the middle. Do they provide something for this in the kit?

[robgraham]

Roger says "Th brush faces outwards in order to seal the top sash when closed. The bottom sash is sealed with the staff bead. "

I don't understand this for the bottom sash as any draught will flow between the parting bead and the outside of the lower sash into the cavity between the sash and the casing, and hence up into the room. Certainly the staff bead seal will have an effect, but I find that if I do a sticky tape seal over the staff bead and sash, then there is still a distinct draught coming up beside the cord.

I like the OP am also unclear as to how to deal with the centre spars.

Rob

[Roger Mills]

The top rail of the lower sash is tapered on the outside, and the bottom rail of the upper sash is tapered on the inside. When the upper sash is fully up and the lower sash is fully down, these two tapers sort of lock together - and are pulled tighter together when you do up the catch. If you still get drafts between them, you can route a groove in one of the tapered bits and insert some v-section draft strip which will then get squeezed between the two tapers when the windows are closed.

[Roger Mills]

See my immediately previous post about the tapers on the centre spars.

I think I said in an even earlier post that these brushes *reduce* rather than totally eliminate the drafts. There will still be a few small gaps which drafts can get through - but nothing like those which exist when there is clearance all the way up the beads.

There's quite a lot of useful information - including some 'how to' videos on Mighton's site. Have a look at

[robgraham]

Thanks for that Roger - the Mighton winged parting bead seems to answer my point, though I would prefer a brush style rather than wings.

Out of interest the name 'parting bead' is clearly obvious, but why 'Staff bead' ? I had to go and look that one up having always just referred to is as the 'retaining bead'.

Rob

[stuart noble]

The wings may be more effective at forcing the upper sash outwards against the box, although pushing it the other way against the parting bead would be better. IME the gap is usually excessive due to wear on the edge of the sash. I tried sinking ball catches into the front of the upper sashes, and it would have worked well had the springs been a little less rigid

[Roger Mills]

at

>>> Thanks for that Roger - the Mighton winged parting bead seems to

Yes, the winged sort would seal in both directions - but I really never fancied it. I don't think you could make wooden parting bead with brushes both sides, unfortunately.

Dunno! I only started doing things to sash windows earlier this year - and that's what they seem to be called - but I've never seen an explanation for the name.

[Roger Mills]

I found that the brushes on the outside of the parting beads were about the right thickness to take up the slack.