Bought a standard softwood casement (from Jeld-Wen cat. I think) but
messed up by assuming sill size was amount of sill projecting from
frame when it meant front-to-back measurement. Now need to replace the
'stub' sill with a full depth one. Should I dismantle, plant a new
piece of timber on or, with moderate skills only with plane etc. take
it to a joinery to get it sorted? Thanks for any polite advice. Peter