box sash windows

Discussion in 'Carpenters' Talk' started by part timer, Dec 2, 2006.

  1. part timer

    part timer New Member

    I have to repair some of these next week-have done them before but would like any hints and tips to get the best results and also the quickest/best ways to replace all or part of a cill.I notice from the carpenter/joiner topic that Dirty Deeds does a lot of these so would appreciate any info from him - and anybody else.
  2. dirtydeeds

    dirtydeeds New Member

    You want a good job?

    So that you only need a finger and thumb to start either sash running? and after that initial touch it runs the whole length of the window unaided?

    If thats what you mean by a good job, you need 300 windows to practice on. Ive seen carpenters who have had that much practice and they still cant do it and NEVER will.

    If its got paint on it remove it, new beading, pulleys. reweight and scribe the sashes to flush the meeting rail. By the way thats a double rehang of both sashes :)

    renewing the whole cill correctly. im not giving that secret away. do it wrong and the box will fall apart in a few years and there will be damp in the building before that.
  3. Mr Mike

    Mr Mike New Member

    Hello part timer,

    Firstly, I have to agree with Deed's comments.

    However, I'm glad that conserving these windows instead of replacement is being discussed here.

    It's impossible to say the best approach for your job, as each window repair's needs will be different and without having seen yours I can't give you a definitive answer.

    I personally am an advocate of the window care systems methods. It's a resin system that is stronger than the original timber and is flexible enough to allow movement without loss of strength or adhesion. This isn't the same, I repeat, isn't the same as using Ronseal 2 part wood filler.

    For small timber decay areas, you can chop away the rotten timber until you get to sound timber with <18% moisture content, and repair with this resin.

    For larger areas, you'd have to chop away the rotten timber and prepare a timber splice that is then bonded in to the rest of the cill using this resin.

    For complete cill replacements, the whole cill is detatched from the mullions, the decayed mullion ends are chopped back to sound timber and the complete cill is replaced and bonded to the existing frame/mullion legs using this resin system.

    For me, and more importantly my customers, I've found this sytem to be outstanding. I wouldn't advocate you trying this without some training first though from the manufacturers. It's not difficult to use, but you have to follow their instructions to the letter for it to be effective.

    I would suggest you need to survey the extent of the rot first. This will dictate whether a timber splice, or complete/partial cill renewal is necessary first.

    If not using the sytem decribed, then you can decide how to most effectively go about splicing in your new timber or cill section. Use well seasoned timber that is a close to the original timber as possible. Keep the grain of you splice running in the same direction as the original timber (obviously), if replacing a complete cill front, in your case use non-ferrous fixings, counterbored & plug the holes with timber plugs (again with the grain running in the same direction if poss.)

    I can only say what I would do. Others will have other ideas/views.
    I will say that normal 2 part wood filler is fine for filling hinge recesses, etc. but I wouldn't use it on external joinery repairs. In my experience it doesn't move with the wood, is brittle and cracks too easily over time. I come across it all too often on poor quality sash repairs.
  4. dirtydeeds

    dirtydeeds New Member

    mr mike, what do you mean by mullion ends? do you mean the pulley stiles?

    the only things connected to a box sash cill are the the bottom of the pulley stiles and the outer and inner cheeks, there is nothing else. ive not mentioned the back of the box because may not have one (i dont mean rotted away either ;))

    by the way what resin system
  5. splinter2

    splinter2 New Member

    To re place a whole cill,I've it done two ways One where the outer-stiles had rotted,which I cut back to good timber then cut the cill at each end,taken the middle part out,then chopped the end parts out with a chisel ,replaced the cill by pushing it in from the front and spliced new timber into the outer stiles.
    The second one was quite simple in the fact that I was not allowed to damage the outer-stiles ,so I took out the stone cill below the window and replaced the cill that way
  6. part timer

    part timer New Member

    Thanks for replies DD and Mr M.Whats the quickest way to chop out any timber? ( hate that bit - well actually can't say I'm thrilled about any of it to be honest) Also as far as renewing pulleys the last ones I did were slightly too big - how best to make the hole at the back of the plate bigger without losing wood for the new screws to fix to? You also say you scribe the sashes - could you explain that a bit more .
    P.S.Do I really have to do 300 windows- I'd rather not!
  7. dirtydeeds

    dirtydeeds New Member

    DO NOT USE a hammer and chisel to enlarge the pockets or you will give yourself a LOT more work, most of the time you will want to make them smaller.

    if the meeting rails dont match (arnt level) after you have removed ALL the paint AND the sashes are running perfectly you will need to scribe the bottom of the bottom sash to match the shape of the cill and the top of the top sash to match the head of the box.

    then you will have to remove the sashes again shoot them in then rehang a second time

    DO NOT scribe the sashes until you have removed ALL the paint and until after the sashes run perfectly. Adding wood to a sash is not easy
  8. Mr Mike

    Mr Mike New Member

    Hi deeds.....sorry mullion ends in terms of casement sashes......pulley stiles in terms of sash windows......

    The resin system is a dutch system called errr....window care systems......I get it from a small company in Suffolk

    ....though it's now being more widely distributed by

    ....better for me as I can pick it up directly from them and save daft carriage charges.
  9. dirtydeeds

    dirtydeeds New Member


    one didnt read ones post as carefuuly as one should
  10. joiner_sim

    joiner_sim New Member

    depends if they need to be done traditionally and what the customer wants, but the more modern windows use springs instead of weights. I use companies who supply these springs such as Mighton, UK Balance & Westward. Just an idea, I only make these boxes from scratch, I don't repair them but out of the older traditional weight to the springs, I prefer the springs.
  11. splinter2

    splinter2 New Member

    God sake , mullions next thing is everyone will be calling them muntins .
  12. dunc

    dunc New Member

    You can repair the bottom sections of the windows and the boxes, as these are the most weathered. Cut out the rot and splice in new sections. I use windowcare to bond everything in, because it works really well.

    I also do a lot of sash upgrades for people wanting double glazed units. Its more practical to have the windows made and fitted into the existing boxes. My suppliers fit the glass and provide the weights.

    The its just a straight forward maintenance procedure.
  13. part timer

    part timer New Member

    Thanks for further replies - really helpful, still can't get up much enthusiasm for doing them - roll on Friday
  14. dirtydeeds

    dirtydeeds New Member

    spring balanced sashes. rubbish and useless

    two vists to fix them, because you cant afford to hold balances in stock. only give 70% benefit to the user. a 50lb sash needs 15lb of effort to move it

    traditional box sash

    with a roll so sash cord you can fix ANY size and ANY weight of sash in one visit.

    when IVE finished a 50lb sash in a traditional box needs less than 2lbs of effort to move it.
  15. isleofwighty

    isleofwighty New Member

    can you explain more about using only 2pound of weight to move a window of 50 pound in weight enlighten me it dosent seem possible
  16. bigwavedave

    bigwavedave New Member

    What he means is that it only takes the equivalent of 2lb of weight/effort to move the sash, not it was strung using a 2lb weight. If the sash is set up properly it should require very little effort to move it regardless of its weight
  17. joesoap

    joesoap New Member

    Yes as I recall the combined weights for the top sash should be just a pound or so more than the sash and the bottom weights just enough to balance the sash.

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