Sash Window repairs - rotting wood

Discussion in 'DIY' started by SecurityGeek, Jan 18, 2011.

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  1. I have the good fortune to live in part of a converted Victorian hospital. One of the benefits are huge sash windows letting in oodles of light.
    One of the disadvantages is having huge wooden sash windows :) the time has come to repaint and this year it will be the goal.

    Happy with most repairs and construction of the windows but I have found some of the bottom part of the outside runners on the frame have rotted beyond the help of filler or stabiliser.
    I am going to replace with new wood but I have hit a wall in the advice to be found on how to fit the replacement wood piece. Do I cut the rotting wood out with a cut 90deg or 45deg in the direction of the frame or 45deg away from the sash window or towards the sill?

    Happy with the rest of the job, securing new wood, planing and sanding down sealing and painting etc. Just this little piece of information I am missing. Any advice apart from get a chippy in?

    Thanks in advance
  2. don't know if you need to replace the whole window - these guys make good (reasonably priced) UPVC replacements
    i've used them - Cheap Box Sash Windows from £167
  3. The main problem with UPVC is that the site lines (thickness of mullions, transoms, and sahses) will be much wider, if in a conservation area or listed building you will not be able to replace them. If they are orginal sliders and still use the weights in the box sash at the sides of the windows, this can be a hell of a job replaceing them with PVC.

    I would get a chippy in who specialises in this, he will be able to set the weights and balance of the sliders, it may not be cheap, but in the long term worth it.

    If its a nice sort of Victorian/Regency type build in a good part of town, original sliders add value, PVC will reduce the values.

    Good luck.
  4. I had to repair 12 sash windows recently (painted solid/ broken sash cords/ rotted sills/ etc); apart from suicidal thoughts and wishing I had the money to rip them all out, I eventually devised a production line process for refurbing them.

    Which bit do you mean by "runner"? If its the batten that stops the window pane from falling out, then its easiest to rip the whole thing out and put in a new cheap bit of batten. If its the part of the box next to the edge of the window, then I find it best to cut in a new piece with only the top & bottom angles - so as to prevent the piece falling through into the weight box (ie same as the fillets that give access to the weights compartment).
  5. follow the link on my post - all sizes / specs are there - these windows look very good and are close to timber sizes
  6. Thanks 4(T), not a blackcat but I have 13 of the beggers to do including 2 large double width ones. Luckily they were in good nick when I moved in so have only minimum work to do in the repair stakes.

    It is the batten (files technical name away for future use) that stops the pane from falling out so I shall take the advice and rip the begger out. I was never really that hot with a saw anyhow.

    Thanks to the others that responded but uPVC is a non-starter, gradeII listed building with all sorts of weird and wonderful clauses around the appearance of the windows.

    My weekends for the next few months when the weather is good would appear to be occupied hammer and paint brush in hand. While I am waiting for the weather to improve I can get out and sort out the external tap pipe which has burst. A fact reported by the indignant howl of my moggy when I opened the stop cock and he took the full force of the water jet a few minutes ago :)

    editted to correct mong spelling
  7. Seeing as your listed now. If you are fairly competent with a chisel and a saw, then replacing glazing beads, and small rotten areas should be ok, obviously using hardwood to replace items. If they are sticking a little bit, it's usually paint build up in the runners, don't though scrape too much off in one go.
    If it is still using the old ropes and weights for traveling, get someone in who knows what they're doing, not just any old chippy, balls it up and you're in a world of hurt.

    As a side note, if you are staying long term, you may be able to fit double glazed unit if the rebate is deep enough, with a smaller bead. It will save you a shed load of cash with heating.

    Any replacement glass you need, that is within 750mm of the floor or within 400mm of an exterior door must either be toughened or laminated. Although in my opinion putting float glass anywhere in house is just wrong and asking for trouble, as it's lethal when broken.

    Anyone else who's thinking of replacing sash windows with PVC. PVC does not have a long term future, will be around for a while yet, but will eventually be phased out.
  8. Good point that, only thing to consider if you do replace with double glazed is you will have to increase the weight of the weights to compensate for the extra weight of the glazing, other wise in the couple of days of summer this year when you want the windows open, you'll have to wedge the windows open or they'll slowly close of there own accord.

    Reading back that sounds confusing, I know what I mean any way, but then I am in my own world.
  9. As Leveller states, any replacement timbers should be qualitative Hardwoods, Sipo or Dark Red Meranti,preferably laminated, some softwoods are also very durable, Siberian Larch, or Douglas Fir, dont use any other softwoods though. Any cuts to the stiles (uprights) must be a scarf cut, its important that you make sure the lowest part of the 45 deg cut is outside in order to prevent rain-water ingress. Treat all new parts with a primer against insect and fungal attack, and use waterproof glues. Dont do the "Everest trick" and use masses of Silicon gunk, this is counter-productive, believe it or not, it actually accelerates rot by entrapping moisture. If you are not able to replace parts because you are not able to use a router or spindle moulder, you can make up and glue up the parts using the appropriate dimensioned timbers, which a Joinery will cut and thickness for small money, or, cut a section of the old rail/stile out and get a Joinery to run you a couple of linear metres off, a good Joiner will have this done in about 1 hour, so costs are kept to a good Friday night down the local.

    Leveller is old-school, and I totally agree with him, uPVC is great when you are about 35 yrs old and spend 15k on your new windows, however, by the time you are nearing your pension, these will either need replacing or at least all the furniture changing and painting (bad news painting plastic). The best "non-timber" windows are the timber-core Aluminum windows, (ask your Bank-manager first), but the best windows and doors, looked after properly are hardwood, and you could be looking at 3 times the life expectancy of uPVC.
  10. And the rest! We have PVC windows that are about 20 years old and falling to bits, yet the wooden sash windows are about 130 years old and good to go after a decent strip, repaint and new sash cords....
  11. Correct, I ve seen fixed sashes getting on for 300 yrs, Oak windows in timber-framed ("Beamed") houses, although it is very difficult to generalise, Mr Smith is a Grunge and refurbs his windows every 20 yrs, however, Mr. Jones who lives next door does his every 5-8 yrs, so, taking the latter, yes, the former, no. What timbers are used, paint-systems etc also contribute to the life expectancies. On the uPVC front, you ve got the usual "why does that one cost 600, and this one 180 quid? Take a Schücco uPVC, thats quality and will do you 30 yrs, then you ve got your Safestyle & Co, which I would personally refuse to fit, I doubt if the cheaper uPVC s even have a steel/alu kern.
  12. Alsacien

    Alsacien LE Moderator

    Cut away the rot and fabricate a piece to fit. In France I was recommended an expanding glue (up to about 5-6mm) that sets hard like tough plastic, there must be similar in UK:
    This is a load bearing beam from the upstairs balcony before sanding, after the expanding glue had gone off I used a very hard wood filler (the grey stuff in the pic) to weather seal the whole thing before a couple of coats of paint. A friend and myself hung off a rope on the end >170kg with no problems.
  13. Yep, any filling of timber, forget all the DIY wood-fillers, I use 2-component Filler, which is almost the same as car-body filler, just a bit more flexible (has Fibre-glass shreds mixed in) available from Würth. The expanding glue is a good idea, although 5-6mm is a bit near the limit, thats why many use it, like expanding foam. Try and get any timber/timber joints as close as poss, and fix with waterproof "white" glue, and clamp it whilst curing, it is not a contact adhesive. This is actually stronger than the timber itself, it will never fail. If it breaks it will always break above or below the glue joint, never the glue joint itself.

    Alsacien, judging from the pic, that looks like a well repaired healthy piece of timber, that ll probably still be in-situ when you are pushing daisies!
  14. We had our Georgian sash windows restored by a company called ventrolla. Worth a look?