Replacing sash window sills


I have a conundrum here:-
I have filled and treated the sills, but for some reason the paint keeps splitting after a few months - I suspect due to differences in materials (I think I did the paint job properly).
So, how difficult is it to replace the sills - I'm reasonably competent with a big hammer #8-)
TIA
Grant
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Depends on which part of the sill has rotted. If it's just the front section, you can usually chop that out neatly back to good timber, using a wood chisel. If it is the rear section as well, then the whole sill will need replacing. Not a job for the faint hearted. Sometimes it is easier to chip back all the rot and then fit some shuttering across. You then fill this with a sharpsand/cement mix. When it has hone off you can paint it to match and it normally lasts longer than the timber.
ken
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Thanks Ken
It would appear to tbe the front bits only - I'm just trying to work exactly how hard they would be to hoik out and replace as by the time I've filled / made good, the time and expense is probably more than a bit of sill wood!
Cheers
Grant
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Sliding sash window?
I would def go for repair rather than replacement if at all possible. The side pieces will be tied (cut) into the sill profile so replacement could be a bit problematic. If you have trouble with the repair shrinking away from the existing wood then you could use magic silicone sealant to seal any gaps although frame sealant will be more paintable. If in an exposed location you could fabricate a flashing with fibreglass resin & tissue; make sure to excise all the rot and moisture before sealing over with this.
--
fred

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Thanks Fred
Do you know if anyone make a readymade of cap fitting that you can bung over the top and forget?
Cheers
Grant
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Nope, anything ready made will fit poorly, leak and result in more problems further down the line. The fibreglass resin approach is quick, tidy and can easily be made to fit the profile of the sill and lap a little up the uprights, making a good seal; available from all good motor factors . . .
--
fred

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