QUESTIONQuality Standards for Slab Countertops- What are the industry standards cocerning granite seams, and the splitting of these seams?
ANSWERANSWER - Countertops are to be flat within 1/8" in 10 feet.
Transition joints from counter to wall or other material is to be 1/8" with a tolerance of +/- 1/64".
Joint seams widths are to be 1/16" with a tolerance of +/- 1/64".
The seams should not split.
Lippage at seams can not be more than 1/32"
The Marble Institute of America has a Dimension Stone Design manual that you can buy.