Repairing and draught proofing sash windows

[Mart]

Hi all,

I've recently moved in to a new house! We moved in at the end of April. The house was built in 1912 and has 15 sash windows. The goal is to bring them back to their full glory.

They range from "pretty good, needs a repaint and draught proofing" through to "significant rot in the sill, bottom rail and stiles, why is there sheet metal instead of wood?!?".

I've given them all a quick assessment and have come up with the following:

• About half of them have rattling panes so I plan to remove and refit with new putty.
• All that I have checked so far open and close, sometimes stiffly. Nothing has been painted shut or had the top window nailed shut. No cords have failed.
• They have rather old plastic secondary glazing installed which I plan to remove once they are in better repair.
• All have flaking paint on frames and sills, I plan to strip and repaint.
• I plan to draught proof all of them – staff beads, parting beads, top and bottom rails.
• On at least one window, mentioned above, we have significant rot meaning i’ll need to replace some of the sash frame and sill.
  • The bottom rail has completely rotted and at some point has been repaired with sheet metal, quite a surprise!
  • The bottom part of at least one of the stiles has also rotted significantly.
  • There may be damage to the sash box and there has been water ingress through the sill, reaching the inside plaster below the window.
  • The sill has rotted and appears to have been repaired at some point with concrete of some sort.

Some of the not so good bits...



I did reach out to Jim Sear (very nice chap) to see if he'd take up the task but unfortunately he's very much in demand and I'm too far away from him to be able to help. So i'm going to attempt to take them on myself, in no small part inspired by this post from Feltwell

My questions

• Feltwell mentioned speaking to local joinery shops however I've failed to find any locally that would be able to cut me new rails, it seems to be mainly joiners who will build entire windows. Maybe I'm just not searching correctly. Any advice for North Hampshire/Surrey/Berkshire?
• For painting - Is linseed paint best or are there other options?
• I plan to draught proof all the sashes, purchasing staff and parting beads pre-installed with brushes/weatherstrips from Mighton or some of the other online suppliers.
• I’d also like to draught proof the top/bottom rails – I’ll need to get a router.
  • Do you have any recommendations? Would a palm router be better or something larger?
• Assuming I can't find local joiners to cut me rails I'll be looking to go it alone - I'm up for the challenge!
  • Where I need to replace any timber I think working with oak would be best for longevity – is this correct?
  • For cutting/shaping rails/stiles and creating tenons I’ll need to get a table saw cant can cut oak and make deep enough cuts, are any other power tools other than table saw and router suggested?
  • I would also need to rout the new rails meaning ovolo(?) router bit – would this be possible with palm router or should I get something a bit more robust?
• I have a very large collection of hand tools from previous projects.

I have previously completed a number of basic woodworking projects from building alcove cabinets, building a custom pergola and installing a kitchen. However I’ve never done any "fine joinery". Having said that I’m confident I can do a good job of this if I have the correct tools and take my time.

I have a large garage that would work as a workshop and I'm happy to invest the money in getting the right tools for the job I have a lot of windows so it would still make sense if I can DIY to an acceptable standard. There are many other projects around the house i'll need to do such as building alcove cabinets and cupboards too.

Will appreciate any guidance

 

[fernicarry]

I'm sure Feltwell will be along to comment more fully soon.

I get sashes made locally for about 150 quid each. Almost all of my bottom sashes have been replaced at some point in the past with rubbish modern soft wood so its no great loss to just bin them even if they are potentially salvageable. Top sashes I keep as most are original to the house and actually none have needed repairs. You might want to look into that as its far less effort than making or repairing. You'll still have your hands full repairing the box and fitting all the replacement beads and other bits of fine-tuning. Times 15, as well as painting inside and out. If you're doing it in your spare time its going to take years to get around them all.

Unlikely to be much use to you but I get repair sections from Express Timber Products in Paisley. They have a good stock of sills and stiles along with all your decorative mouldings and they can make things if you give them a sample. There might be somewhere like that closer to you.

A palm router won't have the power to do deep mouldings but still very useful to have for trimming and grooving. I have used mine to cut a rabbet joint into the stiles to take the repair section and to put a groove across the meeting rail to push a seal into amongst other tasks. I have a big 1600W router for doing moulding work. You'll need a table or a guide rail system if doing long sections as any wobble will mess up the profile.

A multitool is invaluable for lots of reasons but particularly for cutting nails or screws you can't see to get old sections out without causing too much damage. I try to avoid attaching any of the internal joinery to the external when putting back together so that the next time the sill needs to come out it won't wreck everything again. A hacking knife is useful for prying things like staff beads off.

A thicknesser is handy too. A lot of my joinery is 16mm or 5/8" which is a size you can't really get off the shelf but now I can make sections myself from thicker stock.

I would advise against putting a draft strip on the bottom rail as water will get up into the groove and rot it from the inside out. Many of mine were like that.

Paint-wise you'll get lots of opinions on here. I started off with Bedec MSP but I'm not happy with how its performing in some areas and have just switched to Demidekk Ultimate. I am very exposed though. Seal all your cuts and end grain before assembling. That is one of the benefits of doing it yourself, a tradesperson is unlikely to bother.

Best of luck, glad to see you doing the right thing.

 

[Mart]

I'm sure Feltwell will be along to comment more fully soon.

I get sashes made locally for about 150 quid each. Almost all of my bottom sashes have been replaced at some point in the past with rubbish modern soft wood so its no great loss to just bin them even if they are potentially salvageable. Top sashes I keep as most are original to the house and actually none have needed repairs. You might want to look into that as its far less effort than making or repairing. You'll still have your hands full repairing the box and fitting all the replacement beads and other bits of fine-tuning. Times 15, as well as painting inside and out. If you're doing it in your spare time its going to take years to get around them all.

Unlikely to be much use to you but I get repair sections from Express Timber Products in Paisley. They have a good stock of sills and stiles along with all your decorative mouldings and they can make things if you give them a sample. There might be somewhere like that closer to you.

A palm router won't have the power to do deep mouldings but still very useful to have for trimming and grooving. I have used mine to cut a rabbet joint into the stiles to take the repair section and to put a groove across the meeting rail to push a seal into amongst other tasks. I have a big 1600W router for doing moulding work. You'll need a table or a guide rail system if doing long sections as any wobble will mess up the profile.

A multitool is invaluable for lots of reasons but particularly for cutting nails or screws you can't see to get old sections out without causing too much damage. I try to avoid attaching any of the internal joinery to the external when putting back together so that the next time the sill needs to come out it won't wreck everything again. A hacking knife is useful for prying things like staff beads off.

A thicknesser is handy too. A lot of my joinery is 16mm or 5/8" which is a size you can't really get off the shelf but now I can make sections myself from thicker stock.

I would advise against putting a draft strip on the bottom rail as water will get up into the groove and rot it from the inside out. Many of mine were like that.

Paint-wise you'll get lots of opinions on here. I started off with Bedec MSP but I'm not happy with how its performing in some areas and have just switched to Demidekk Ultimate. I am very exposed though. Seal all your cuts and end grain before assembling. That is one of the benefits of doing it yourself, a tradesperson is unlikely to bother.

Best of luck, glad to see you doing the right thing.

Thank you for the feedback, I hadn't considered contacting local joiners to rebuild individual sashes, great idea that I'll look in to.

I have a multitool and it indeed is very useful - I can see how it will be with the windows too.

Good shout on the bottom rail, I think it would be sealed by the staff bead seal anyway so probably unnecessary.

 

[mardinor]

Well done on saving beautiful windows. From the photos they look totally salvageable.

Agree on Bedec MSP or Jotun Demidekk Ultimate.

All I'd add, is that while repairing with proper remade pieces and scarf joints is the best solution (and if you do, consider hard wood or accoya), the next best is to use flexible 2-part fillers. These are made for exactly this job and might be handy for more borderline repairs. Critical, though is to use the proper ones (eg RepairCare or Timberbuild) which are expensive but flexible and wont crack after a few seasons; classic 2-part 'car body filler'-style (eg Ronseal) fall out after a year or two.

 

[Mart]

Well done on saving beautiful windows. From the photos they look totally salvageable.

Agree on Bedec MSP or Jotun Demidekk Ultimate.

All I'd add, is that while repairing with proper remade pieces and scarf joints is the best solution (and if you do, consider hard wood or accoya), the next best is to use flexible 2-part fillers. These are made for exactly this job and might be handy for more borderline repairs. Critical, though is to use the proper ones (eg RepairCare or Timberbuild) which are expensive but flexible and wont crack after a few seasons; classic 2-part 'car body filler'-style (eg Ronseal) fall out after a year or two.

Thank you for this, with the amount of windows that I need to refurb there's no doubt that there will need to be a compromise at some point so the 2-part fillers is another excellent option i'll look in to. Do you have experience with the RepairCare of Timberbuild? Any preferences?

 

[Stevers]

Last Autumn I used 3C wood hardener and epoxy fillers to repair my bargeboards; I really liked the smooth consistency and long working time of the 3C epoxy filler, leading to almost no waste.
https://www.sealantsonline.co.uk/Products/Epoxy-fillers/CCC0081
There is plenty left over for me to tackle my sash windows this summer, and I have also used it to put one upright of a stone fireplace surround back together. The 3C epoxy wood hardener is very effective. It is blue in colour, which is claimed to prove that the wood has been treated, but I would have preferred it to be clear.
I have no connection with 3C other than being a satisfied customer.

 

[Feltwell]

Hi all,

I've recently moved in to a new house! We moved in at the end of April. The house was built in 1912 and has 15 sash windows. The goal is to bring them back to their full glory.
View attachment 10730View attachment 10737
They range from "pretty good, needs a repaint and draught proofing" through to "significant rot in the sill, bottom rail and stiles, why is there sheet metal instead of wood?!?".

I've given them all a quick assessment and have come up with the following:

• About half of them have rattling panes so I plan to remove and refit with new putty.
• All that I have checked so far open and close, sometimes stiffly. Nothing has been painted shut or had the top window nailed shut. No cords have failed.
• They have rather old plastic secondary glazing installed which I plan to remove once they are in better repair.
• All have flaking paint on frames and sills, I plan to strip and repaint.
• I plan to draught proof all of them – staff beads, parting beads, top and bottom rails.
• On at least one window, mentioned above, we have significant rot meaning i’ll need to replace some of the sash frame and sill.
  • The bottom rail has completely rotted and at some point has been repaired with sheet metal, quite a surprise!
  • The bottom part of at least one of the stiles has also rotted significantly.
  • There may be damage to the sash box and there has been water ingress through the sill, reaching the inside plaster below the window.
  • The sill has rotted and appears to have been repaired at some point with concrete of some sort.

Some of the not so good bits...
View attachment 10731View attachment 10732
View attachment 10733View attachment 10734View attachment 10735View attachment 10736

I did reach out to Jim Sear (very nice chap) to see if he'd take up the task but unfortunately he's very much in demand and I'm too far away from him to be able to help. So i'm going to attempt to take them on myself, in no small part inspired by this post from Feltwell

My questions

• Feltwell mentioned speaking to local joinery shops however I've failed to find any locally that would be able to cut me new rails, it seems to be mainly joiners who will build entire windows. Maybe I'm just not searching correctly. Any advice for North Hampshire/Surrey/Berkshire?
• For painting - Is linseed paint best or are there other options?
• I plan to draught proof all the sashes, purchasing staff and parting beads pre-installed with brushes/weatherstrips from Mighton or some of the other online suppliers.
• I’d also like to draught proof the top/bottom rails – I’ll need to get a router.
  • Do you have any recommendations? Would a palm router be better or something larger?
• Assuming I can't find local joiners to cut me rails I'll be looking to go it alone - I'm up for the challenge!
  • Where I need to replace any timber I think working with oak would be best for longevity – is this correct?
  • For cutting/shaping rails/stiles and creating tenons I’ll need to get a table saw cant can cut oak and make deep enough cuts, are any other power tools other than table saw and router suggested?
  • I would also need to rout the new rails meaning ovolo(?) router bit – would this be possible with palm router or should I get something a bit more robust?
• I have a very large collection of hand tools from previous projects.

I have previously completed a number of basic woodworking projects from building alcove cabinets, building a custom pergola and installing a kitchen. However I’ve never done any "fine joinery". Having said that I’m confident I can do a good job of this if I have the correct tools and take my time.

I have a large garage that would work as a workshop and I'm happy to invest the money in getting the right tools for the job I have a lot of windows so it would still make sense if I can DIY to an acceptable standard. There are many other projects around the house i'll need to do such as building alcove cabinets and cupboards too.

Will appreciate any guidance

Hello! Quick reply as it's very late, but on finding a joinery shop -

Yes, it's somewhere that makes doors, windows, staircases etc that you want. The trick is finding a friendly one that will let you raid their offcut store and will do the odd bit of machining to size - look for the smaller ones, boss plus 1 or 2 joiners at most. Rather than ringing round the best way is wander in with what you need doing in hand (like a bit of the rotten rail you need cutting) and ask at the counter - saying "No" is always harder face to face! Maybe I'm just lucky, but in my small town I've got 2 joinery shops to call upon, either of whom will do odd small jobs, especially if cash is involved and the hassle of issuing a receipt is not required.......

 

[housewinnie]

I have just used Repaircare fillers, bought the trial kit for £70 very good value. The stuff is great smooths out and doesnt pull when filling deep areas. Best filler I have ever used.

 

[mardinor]

I’ve only used Repaircare, not other brands. Very pleased with all Repaircare products - loads of open working time and easy to use. Repairs are now over 10 years old, to sashes in worse condition than your photos, and no cracking whatsoever. Can’t comment on other brands like 3C or Timbabuild, but I used to lurk on a painter’s forum and the consensus there was they are cheaper but harder to work.

Tips from experience using: for big gaps, fill the void with scrap wood to save money, making sure at least 5mm of filler surrounding all sides; invest in a hand grinder or palm router to remove rotten wood (they sell a £400 version for pros but a £20 Aldi version works well); don’t fill anything less than 5mm unless you use their surface filler, route out instead; really recommend their modern putty alternative.

 

[Mart]

Thanks all, seems I need to get hold of some repaircare and crack on! I have contacted a few localish joiners to see if they can take on the single window and sash that is rotted through so I can focus my efforts on getting the rest up to scratch.

 

[Mart]

Hi all, thought it would be worth giving an update on this.

Other projects have gotten in the way but I've so far renovated two windows.

They won't be winning any beauty pageant but i'm confident that they are secure, draught free and well protected from the environment. It's been very rewarding and i'm learning a lot as I go.

Some observations i've made.

• I chose to go with parting and staff beads with Qlon seals - this was no good as they provided way too much friction. I've now moved to brush seals which are buttery smooth.
• Using Bedec MSP - fantastic paint, goes on easily and dries quickly.
• I've not touched the outer staff bead as it's rendered in, i've found this is making the top sashes quite sticky whereas the bottom sashes can be moved with a single finger - anything I can do about this?
• Installing parting beads has also been a challenge. I went for 8mm when in hindsight should have got 7mm. Might need to bite the bullet and order the correct size however so far i've been routing to reduce the thickness - this may also be contributing to the sticky top sashes.
• I've found a supplier for fillers and glazing sealant - Oxera repair. They are very competitive on price and the quality seems great so far with the glazing i've done and cill rot i've needed to fix.
• Two areas that are slowing me down and i'm not happy on my workmanship are cutting the staff beads and routing the sides of the sashes to make room for the sash cord cleats.
  • The staff beads are coming out very rough and me measurements seem to be off sometimes by a considerable margin. I guess measure better is the solution!
  • I'm routing the sides of the sashes free hand to accept the cleats, they are rough but so far no massive mishaps. However I have to do this many more times so perhaps some kind of jig would be the best approach to avoid any disasters. I've no idea how i'd secure a jig to the side of the sash.
• The help and guidance from other threads on this forum have given me a huge amount of confidence to tackle any issues that have come my way - it's been greatly appreciated!

 

[fernicarry]

I've not touched the outer staff bead as it's rendered in, i've found this is making the top sashes quite sticky whereas the bottom sashes can be moved with a single finger - anything I can do about this?

The outer lining? Yeah, my top sashes are a lot more grungy than the bottoms in terms of movement. Get all the overpaint off the inside edge of the lining where the sash runs against it, although in your pic it doesn't look too bad. Similarly the thickness of paint on the sash might have reduced the clearance but I think you've stripped completely? Maybe waxing the edge of the top sash will help?

Check the lining is still perpendicular to the stile. Its just nailed on and after time the nails aren't very secure. The pointing around it might have pushed it inwards a bit.

The outer pulleys might be a bit more sticky than the inner ones due to being a bit more exposed. I generally replace the inner ones with new ball raced ones which makes an enormous difference, so much so that I usually need to add weight to keep the sash in balance where previously the stiction in the pulley was enough to keep it from dropping (modern glass is thicker and heavier). I don't do the outer pulleys mainly because I've been unable to find any with the exact same size of foreplate and not being painted the difference would be noticeable if I used a smaller one. A clean up and a splash of WD40 may help.

One of my top sashes is very tight which appears to be down to the distance between the parting bead and the outer lining. Have to conclude it was just made that way because I can't see how its changed over time. I've put the thinnest brush strips into the parting bead as possible but yeah its a bit of a battle to open it. As you say if you've reduced the thickness of the parting bead on its outside edge then it will overhang by 1mm reducing the gap somewhat so maybe best to go with the thinner beads.

The staff beads are coming out very rough and me measurements seem to be off sometimes by a considerable margin. I guess measure better is the solution!

Where are you cutting? Are you routing the existing staff beads for the brush strip?

Good work so far!

 

[Mart]

The outer lining? Yeah, my top sashes are a lot more grungy than the bottoms in terms of movement. Get all the overpaint off the inside edge of the lining where the sash runs against it, although in your pic it doesn't look too bad. Similarly the thickness of paint on the sash might have reduced the clearance but I think you've stripped completely? Maybe waxing the edge of the top sash will help?

Check the lining is still perpendicular to the stile. Its just nailed on and after time the nails aren't very secure. The pointing around it might have pushed it inwards a bit.

The outer pulleys might be a bit more sticky than the inner ones due to being a bit more exposed. I generally replace the inner ones with new ball raced ones which makes an enormous difference, so much so that I usually need to add weight to keep the sash in balance where previously the stiction in the pulley was enough to keep it from dropping (modern glass is thicker and heavier). I don't do the outer pulleys mainly because I've been unable to find any with the exact same size of foreplate and not being painted the difference would be noticeable if I used a smaller one. A clean up and a splash of WD40 may help.

One of my top sashes is very tight which appears to be down to the distance between the parting bead and the outer lining. Have to conclude it was just made that way because I can't see how its changed over time. I've put the thinnest brush strips into the parting bead as possible but yeah its a bit of a battle to open it. As you say if you've reduced the thickness of the parting bead on its outside edge then it will overhang by 1mm reducing the gap somewhat so maybe best to go with the thinner beads.



Where are you cutting? Are you routing the existing staff beads for the brush strip?

Good work so far!

Yes outer lining - I might try wax. Windows were stripped before repainting but MSP can take up to a month to fully cure so perhaps over time it'll smooth out a bit too. I'm very likely going to get the thinner parting beads for the rest of the windows so that 1mm extra will help.

The pullys are not pretty but with a bit of WD40 and some oil they are very smooth so i've opted not to replace them so far.

I've bought new staff beads with a channel for adding draught stripping. I'm currently cutting using a miter block and fine toothed saw but it's a bit shonky. I'm considering getting a cheap powered miter saw. It's probably mainly due to me rushing.

My biggest challenge is time, I work Monday to Friday so am trying to renovate a complete window over each weekend. If I had more time i know I could do a better/neater job but it's a bit of a race to get the window back in before work on Monday. I probably shaved half a day off my second window.

If i could really streamline the process it would be great to confidently do two at a time - it would also mean less downtime waiting for paint to dry etc.

 

[fernicarry]

I've bought new staff beads with a channel for adding draught stripping. I'm currently cutting using a miter block and fine toothed saw but it's a bit shonky. I'm considering getting a cheap powered miter saw. It's probably mainly due to me rushing.

Ah, I see, yes measuring an inside dimension, especially a long one can be less than accurate. One trick is to put a mark part way and measure from each extremity up to the mark then add the two up.

The side staff beads should be cut slightly over anyway and then flexed into place like an archery bow.

A mitre saw will definitely help with the accuracy of the cut, I couldn't be without mine. And its a lot easier to shave a hair's width off than by hand so you can start a bit over and then home in on the correct dimension. I have made sooo many trips out to the garage...

I've started using a little microfibre roller which has really sped up the time taken to do a coat, especially on those long beads. These -- https://twofussyblokes.com/ -- are very nice but even cheapo screwfix stuff was fine.

 

[Mart]

I'm spending more time in my garage than my house most weekends now!

Thanks for the tips. I've ordered the 7mm parting beads and will be treating myself to a mitre saw and some mini rollers.

 

[Sarah dobe]

Still needs some tweaking but I don’t this Saturday afternoon . Used repair care dry flex 16 I’ve used it on almost all of my windows , scarfed bits in places

 

[Mart]

Great job! how did you get such sharp corners? I have a sash where the entire bottom rail and bottom of both stiles are completely rotten - that'll be a fun one!

 

[Sarah dobe]

I used a palm sander , filled the little imperfections this evening , with repair care surface filler . Had the top sash to do to . We thought about replacing the sash but I like a challenging ..good job too .. it’s a really labour of love isnt it !

 

[Feltwell]

Very quick reply - "sticky" sashes - silicone spray works wonders, better than wax.

 

[Feltwell]

Ah, I see, yes measuring an inside dimension, especially a long one can be less than accurate. One trick is to put a mark part way and measure from each extremity up to the mark then add the two up.

Treat yourself to one of these - very useful for internal measurements, and repitive marking.

https://www.amazon.co.uk/Hultafors-...73&hvtargid=pla-563524355439&psc=1&th=1&psc=1