mlv wrote:

I have to build some external tiled window sills on an extension to match
with an existing building.

The sills are two layers of cut-down plain concrete roof tiles (Redland)
cemented with staggered joints to the outer leaf at a downward angle
directly below the window aperture.

This doesn't look too easy to achieve without some sort of wooden frame/jig
that will hold the tiles in the correct position and at the right angle
whilst the cement cures.

Has anyone built a tiled sill? Any tips on how best to do it?

No, but if its like the ones we had, its pretty easy. Tht is a tile was
laid over teh clill interior first, then provbaly weighted down, the
next day teh top layer could be moratterd on. In our case there was a
slid oag frame on tpp off or butted up to the top tile layer.


The stiff mortar will hold the angle you want of itself.


TIA