Conservatory window sill angle cutting.

[Fat ferret]

Hi I am replacing the sill on a wooden conservatory as it has rotted.

I made up new sills to match the old but am not sure how to mark the angles where the sills join as the conservatory is octagonal. How do I mark them for cutting? I could copy the angle on the existing sills but not easy as it's the joins where they have rotted most. Sure there is an easy way.

I have a combi square, a sliding bevel and a puzzled expression. Please help.

 

[Myfordman]

Measure the corner angle somewhere else on the frame and bi-sect it to get the mitre angle

Rather than work with numerical angles you could cut a template to fit the corner, creeping up on the angle for a good fit. Draw lines on the template parallel to the cut edges. join the point where the lines intersect to the cut internal angle on the template and that will be the mitre angle.

 

[RobinBHM]

If its an octagon, that would be 22.5 degrees

Are all the angles the same? -they arent always.

If your cill has a tongue, then remember not to mark at the shoulder position of the cill, not the inside edge.