Update
I managed to get on top of the porch and i did this myself, i trimmed the putty off and reapplied fresh putty
Either side of the sill was about 1cm gap - it seemed a bit big for silicone so i carefully applied some expanding foam and sanded to flush when it set
Looks fine, but i suddenly thought- do i need gaps at the side of the window sill for expansion and contraction? or am i over thinking it?
I managed to get on top of the porch and i did this myself, i trimmed the putty off and reapplied fresh putty
Either side of the sill was about 1cm gap - it seemed a bit big for silicone so i carefully applied some expanding foam and sanded to flush when it set
Looks fine, but i suddenly thought- do i need gaps at the side of the window sill for expansion and contraction? or am i over thinking it?