Are there guidelines or code requirements for the force of gravel compactors? I am wondering about what size machine to use; is a 4000 lbf machine large enough, or does one need 5000 lbf? I plan on compacting damp gravel/fines in 8″ lifts under my footers, around the foundation walls, and under the slab. One manufacturer said their 4000 lbf machine would be plenty adequate, one manufacturer said their 2475 lbf machine will compact to 12″ (probably ideal conditions), and a gent on another forum said to only compact 4″ at a time. The general recommendation around here is “no more than 8″ lifts, with a machine in the 225 lb class” (which translates to about 4000-4500 lbf of force, from all the specs I’ve read). Thanks. john