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?

TIA
--
Mike
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