Hardwod cills over masonry

[Citizen69]

Im replacing a rotten wood cill, with a hardwood cill over the masonry cill.
Question: should a wood cill be separated from the masonry cill, so that the drip rebate underneath is utilised, I see so many where the wood cill sits directly on top of the masonry and the join is filleted/painted? Is the drip rebate underneath only for wood overhang cills - if so then presumably a patio door wood cill (with no rebate) would be a suitable option for a window with a masonry ledge.
Thanks


When you did nt get what you wanted, you got experience!

 

[Burnerman]

Ideally, the masonry cill should have a slope so any water dripping on it will be cast over the wall.
The drip rebate is to prevent water from running back under the timber cill, and should be allowed to do its job wherever possible.
John