I have a 4mx4m area of grass that I'm replacing with artificial turf. The grass was bordered with stone setts which are set in a bed of mortar. I know I need to create a wooden framework to nail the grass into, however having removed the turf, the 3x1 timber lengths won't sit flush against the stone setts, a) because the setts are naturally uneven and b) because of the mortar bed jutting out (See picture)
I'm struggling with what to do... even if I didn't bother with the wooden frame, and just used the U shaped grass pins at the edges - the pins would just hit the mortar bed and bend. Other than grinding out the mortar bed as much as possible - are there any other options?