I'm having a real problem hanging some kitchen wall units. The problem is that the wall isn't straight. The first four units hang nicely and butt up against each other front and back. But then the wall starts to slope away slightly such that although the units butt up together at the back, there is a 5mm gap at the front. I've been trying to pack them at the back using a wedge made of successive layers of 4mm pine strip, but I can't get it to look right. After 3 more units, the last one is about 16mm away from the wall at one end.
Is there a better solution, other than rebuilding the wall?