Our firm does a lot of kitchen remodeling, and recently we had to extend an existing marble countertop a few feet. Locating a similar piece of marble was hard enough, but the real test came during installation; any unevenness in the glossy surface would be quite noticeable.
We got a precise fit by using a flathead screw under each corner of the new piece. The screws were easily adjusted to the right elevation, and they kept the heavy marble from sinking into the slowly curing mastic.
—Max Durney, Petaluma, CA
Edited and illustrated by Charles Miller
From Fine Homebuilding #11
How were the screws easily adjusted???
I'm not a pro but I have installed several granite counter tops.....
I screw up from the bottom until both pieces are even. Done.
I just accepted a job where I have to build up an uneven lip under a garage door, so there will be a seal when the door is down. My concern was determining the necessary height for the lip along a 6 foot length. One solution is several Titens adjusted to contact the bottom of the door, then used as gauges when I trowel the concrete, similar to the picture above.