Windowsill under a sloping skylight
"We (my wife and I) are currently there, to expand our attic and we are faced with some questions. I hope, You can answer them to us.
1. We want to be around 80 cm height put a knee stick made of wood. How strong should the wood be?
2. We would like to install window sills in the slopes under the skylights. What's the easiest way to do that?? A note on the windows, that they are at a height of around 120 cm above the floor, so about 80 cm above the knee.
Your first question: We recommend a frame made of normal roof battens. Fasten a crossbar on the floor and one on the roof slope, in between at a distance of at most 60 cm vertical slat sections with angles. The knee stick can be planked with chipboard, Plasterboard or lightweight board are equally good.
Your second question is not that easy to answer, since the construction of a window sill on a skylight depends on the roof pitch. You can easily lengthen the window reveal under a steep roof (maximum up to the knee) and use a narrow or protruding window sill. It is recommended for flat roof slopes, To put a low shelf or a sideboard in front of the window, to keep enough storage space. Also a built-in shelf, that supports a larger window sill from below, is conceivable.