Feltwell
Member
- Messages
- 6,377
- Location
- Shropshire, England
Quite a while ago - really quite a while ago - I said I'd do a post on the basics of sash window repair & improvement, to hopefully encourage anyone who's looking at their windows and doubting their abilities that a sash window is perfectly repairable by an enthusiastic amateur - and that those windows can look good & work well afterwards! Sash windows do not have to be heavy, awkward things to open that rattle in high winds and let drafts in! You certainly don't need to replace them to get a window that works smoothly and keeps the drafts out.
This post is definitely not intended to be a masterclass in sash window repair - that's the whole point, I'm no expert, I'm certainly not a time served carpenter, but I've managed to successfully repair and significantly improve the usability of my windows and significantly extend their life.
There are different ways to repair them - this is just my way of doing it. This post is aimed at the beginner, so for those with knowledge already please don't think I'm being patronising. I did a previous post showing much more extensive repairs to a bay window which seemed to go down well, but I didn't really say anything about how to strip and rebuild the window, that a beginner would need to know.
https://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=16118&p=219935&hilit=bay#p219935
So, what's our patient? It's a Victorian 2 over 1 box sash window, made in 1899 and heavily neglected since. Why "2 over 1"? Just the number of glass panes, 2 on the top and 1 on the bottom. It's one of the first floor windows on this old picture. Why is it a "box sash"? The weights in the frame (that counterbalance the weight of the window) travel up and down in a "box" within the frame. This is a very typical window for it's period, the box being hidden, mounted behind the facing brickwork of the house.
The good news is, sash windows can be renovated entirely from the inside. Stripping the old paint off is a bit easier if you can access from the outside, but it can all be done from the inside.
So this window is in fairly typical condition. It looks rough from the outside, much of the putty holding the glass in is missing and the paint is peeling. The top sash has been painted shut, the bottom sash is difficult to open, rattles in the wind and lets a draft in.
First thing, be prepared to board your window up at the end of the day - especially if you are redecorating it, you won't get this job done in a single day. Have a piece of OSB or cheap ply cut to size and ready to use.
Next, a tool that is both cheap and I think invaluable for this job and many others that I strongly suggest you treat yourself to - a small pry bar with a curved blade on one end, like this:-
https://www.screwfix.com/p/magnusson-pry-bar-8/8640v
Even better, get a set of bars, you'll use them! https://www.screwfix.com/p/magnusson-bar-set-3-pieces/5341v
First job is to remove the "staff beads", which hold the bottom sash in place. They will normally be nailed in place and stuck with paint. Use the blade on the small pry bar, start in the middle on the uprights and hammer it along the joint to break the paint line - then hammer against the curved part of the bead towards the middle of the window - once it starts to move they usually come off quite easily. Don't worry if you damage or break them, you'll be replacing them anyway. Try not to lever against the frame. All 4 beads come out as they all get changed.
The bottom sash is now able to swing into the room on it's cords.
The cords are simply nailed in grooves in the sides of the sash - you'll be replacing them so you can carefully cut them - easiest done with an assistant, get them to cut them close to the sash and tie a knot in the end before carefully letting the cord go back over the pulley, lowering the weight gently until the knot jams in the pulley.
Next up is removing the "parting beads" - which keep the 2 sliding sashes apart - and the top sash.
But first off, a word of caution.
The top sash is often painted shut, if yours is and you're not careful it can suddenly release and come down like a guillotine and injure you. Why? Well, people had a habit of just nailing the sash shut if the cords broke, and those nails may well have rusted through and it's just the paint holding it in place. Or, someone many years ago may have carelessly decorated and painted it shut in position, then either the sash cords have rotted later (original ones were just made of cotton rope) and the weights have dropped, or - as has happened to me - as soon as you disturb the window the cords break, sending the weights crashing to the bottom of the box! Fortunately with the window shut the weights are near the bottom anyway, so don't have far to fall.
So, I strongly recommend you prop it up with an appropriate size bit of wood or even better use 2 clamps if you have some long enough and that can be reversed to be used as a spreader.
You don't need the scaffold tower! I had it there for other jobs, it is a help with this but not essential at all.
Next thing is to get the parting beads out. You will almost certainly break them, they are getting replaced so don't worry. Using your trusty little pry bar, gently tap the curved blade in between the parting beads and the top sash all the way along on both sides to break the paint line.
The bead just sits in a groove in the frame and pulls out - it may have been nailed in as well - and you may need to work along the edge on both sides with your pry bar blade and a hammer and break the paint line to free it.
Run a small chisel along the bottom of the groove to remove any stuck remnants, never try to lever them out from the sides, you'll just cause damage.
Next thing is to ascertain if the top sash is free - if you're lucky, or if it wasn't painted shut to begin with, it will just swing in and can be removed in the same way as the bottom sash.
If it's stuck, first thing is to find out if it's been nailed shut. *Usually* if someone has done this they will have nailed through the "horns":-
You may be able to see the nails - you can in my picture above, someone nailed under the horn rather than through it, which is rare and helpful! You may be able to pass something thin (like a steel ruler) behind the horn to feel if there is any obstruction, you may need to take the paint off the horn with a heat gun to see. The easiest and least damaging way to deal with nails, especially if they've been hammered with heads flush or recessed, is to use an oscillating multi-tool (like this https://www.screwfix.com/p/erbauer-emt300-qc-300w-electric-multi-tool-220-240v/622fx) with a metal cutting blade to slip behind the horn and cut through the nail - but if that's not possible you'll need to resort to whatever means necessary, accept that using pliers or the pry bar head will cause a little damage to the horn that will need filling later.
If you've dealt with the nails or there weren't any and it's still stuck, it's most likely just the paint around the perimeter on the outside that's holding it in. A bit of gentle "persuasion" pulling it into the room usually does the trick. If not you'll have to go round the outside edge with your pry bar blade and a hammer and break the paint line - this is when an assistant to hold the sash, and sometimes the ability to get to the outside rather than trying to reach up from the inside & below, makes life easier.
You've now got both sashes and all the beads out, next job is to remove the "pocket covers". These are bits of wood in the side of the frame, low down, that give access to the weights - the parting bead groove runs down the middle of them. You should be able to see their outline in the paint, if not you may need to strip the paint off. You can see the bottom of the cover at the top of this picture, about 6" up from the cill, with a screw driven into it.
Go round the outside of the cover with your trusty pry bar blade and hammer and break the paint line. There should be nothing other than friction holding the cover in, but just have a look over it first to check, sometimes there is a screw at the bottom. Do *not* try to lever it out at the edge - you'll often notice damage where some numpty has done this in the past! The cover comes out bottom edge first, the top is shaped and held in place. I find the best way to get it out with no damage is to drive a screw into the bottom of the parting bead groove about an inch up from the bottom of the cover, as in the picture above - then lever it out using a larger pry bar, against a bit of scrap wood on the frame below.
Now the sash pocket is out, you can untie the knot in the sash cord and remove the weights - and that is the disassembly stage done. The next "thrilling instalment" will be the repairs and the start of reassembly...……..
This post is definitely not intended to be a masterclass in sash window repair - that's the whole point, I'm no expert, I'm certainly not a time served carpenter, but I've managed to successfully repair and significantly improve the usability of my windows and significantly extend their life.
There are different ways to repair them - this is just my way of doing it. This post is aimed at the beginner, so for those with knowledge already please don't think I'm being patronising. I did a previous post showing much more extensive repairs to a bay window which seemed to go down well, but I didn't really say anything about how to strip and rebuild the window, that a beginner would need to know.
https://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=16118&p=219935&hilit=bay#p219935
So, what's our patient? It's a Victorian 2 over 1 box sash window, made in 1899 and heavily neglected since. Why "2 over 1"? Just the number of glass panes, 2 on the top and 1 on the bottom. It's one of the first floor windows on this old picture. Why is it a "box sash"? The weights in the frame (that counterbalance the weight of the window) travel up and down in a "box" within the frame. This is a very typical window for it's period, the box being hidden, mounted behind the facing brickwork of the house.
The good news is, sash windows can be renovated entirely from the inside. Stripping the old paint off is a bit easier if you can access from the outside, but it can all be done from the inside.
So this window is in fairly typical condition. It looks rough from the outside, much of the putty holding the glass in is missing and the paint is peeling. The top sash has been painted shut, the bottom sash is difficult to open, rattles in the wind and lets a draft in.
First thing, be prepared to board your window up at the end of the day - especially if you are redecorating it, you won't get this job done in a single day. Have a piece of OSB or cheap ply cut to size and ready to use.
Next, a tool that is both cheap and I think invaluable for this job and many others that I strongly suggest you treat yourself to - a small pry bar with a curved blade on one end, like this:-
https://www.screwfix.com/p/magnusson-pry-bar-8/8640v
Even better, get a set of bars, you'll use them! https://www.screwfix.com/p/magnusson-bar-set-3-pieces/5341v
First job is to remove the "staff beads", which hold the bottom sash in place. They will normally be nailed in place and stuck with paint. Use the blade on the small pry bar, start in the middle on the uprights and hammer it along the joint to break the paint line - then hammer against the curved part of the bead towards the middle of the window - once it starts to move they usually come off quite easily. Don't worry if you damage or break them, you'll be replacing them anyway. Try not to lever against the frame. All 4 beads come out as they all get changed.
The bottom sash is now able to swing into the room on it's cords.
The cords are simply nailed in grooves in the sides of the sash - you'll be replacing them so you can carefully cut them - easiest done with an assistant, get them to cut them close to the sash and tie a knot in the end before carefully letting the cord go back over the pulley, lowering the weight gently until the knot jams in the pulley.
Next up is removing the "parting beads" - which keep the 2 sliding sashes apart - and the top sash.
But first off, a word of caution.
The top sash is often painted shut, if yours is and you're not careful it can suddenly release and come down like a guillotine and injure you. Why? Well, people had a habit of just nailing the sash shut if the cords broke, and those nails may well have rusted through and it's just the paint holding it in place. Or, someone many years ago may have carelessly decorated and painted it shut in position, then either the sash cords have rotted later (original ones were just made of cotton rope) and the weights have dropped, or - as has happened to me - as soon as you disturb the window the cords break, sending the weights crashing to the bottom of the box! Fortunately with the window shut the weights are near the bottom anyway, so don't have far to fall.
So, I strongly recommend you prop it up with an appropriate size bit of wood or even better use 2 clamps if you have some long enough and that can be reversed to be used as a spreader.
You don't need the scaffold tower! I had it there for other jobs, it is a help with this but not essential at all.
Next thing is to get the parting beads out. You will almost certainly break them, they are getting replaced so don't worry. Using your trusty little pry bar, gently tap the curved blade in between the parting beads and the top sash all the way along on both sides to break the paint line.
The bead just sits in a groove in the frame and pulls out - it may have been nailed in as well - and you may need to work along the edge on both sides with your pry bar blade and a hammer and break the paint line to free it.
Run a small chisel along the bottom of the groove to remove any stuck remnants, never try to lever them out from the sides, you'll just cause damage.
Next thing is to ascertain if the top sash is free - if you're lucky, or if it wasn't painted shut to begin with, it will just swing in and can be removed in the same way as the bottom sash.
If it's stuck, first thing is to find out if it's been nailed shut. *Usually* if someone has done this they will have nailed through the "horns":-
You may be able to see the nails - you can in my picture above, someone nailed under the horn rather than through it, which is rare and helpful! You may be able to pass something thin (like a steel ruler) behind the horn to feel if there is any obstruction, you may need to take the paint off the horn with a heat gun to see. The easiest and least damaging way to deal with nails, especially if they've been hammered with heads flush or recessed, is to use an oscillating multi-tool (like this https://www.screwfix.com/p/erbauer-emt300-qc-300w-electric-multi-tool-220-240v/622fx) with a metal cutting blade to slip behind the horn and cut through the nail - but if that's not possible you'll need to resort to whatever means necessary, accept that using pliers or the pry bar head will cause a little damage to the horn that will need filling later.
If you've dealt with the nails or there weren't any and it's still stuck, it's most likely just the paint around the perimeter on the outside that's holding it in. A bit of gentle "persuasion" pulling it into the room usually does the trick. If not you'll have to go round the outside edge with your pry bar blade and a hammer and break the paint line - this is when an assistant to hold the sash, and sometimes the ability to get to the outside rather than trying to reach up from the inside & below, makes life easier.
You've now got both sashes and all the beads out, next job is to remove the "pocket covers". These are bits of wood in the side of the frame, low down, that give access to the weights - the parting bead groove runs down the middle of them. You should be able to see their outline in the paint, if not you may need to strip the paint off. You can see the bottom of the cover at the top of this picture, about 6" up from the cill, with a screw driven into it.
Go round the outside of the cover with your trusty pry bar blade and hammer and break the paint line. There should be nothing other than friction holding the cover in, but just have a look over it first to check, sometimes there is a screw at the bottom. Do *not* try to lever it out at the edge - you'll often notice damage where some numpty has done this in the past! The cover comes out bottom edge first, the top is shaped and held in place. I find the best way to get it out with no damage is to drive a screw into the bottom of the parting bead groove about an inch up from the bottom of the cover, as in the picture above - then lever it out using a larger pry bar, against a bit of scrap wood on the frame below.
Now the sash pocket is out, you can untie the knot in the sash cord and remove the weights - and that is the disassembly stage done. The next "thrilling instalment" will be the repairs and the start of reassembly...……..
