A rolling cart has a wheeled frame, telescoping vertically extendable members with glide strips, and a tiltable frame having glide strips interspersed with transfer balls to easily slide slabs or sheet materials for construction such as when installing countertops. A method is also described for measuring a minuend desired install height, subtracting a geometrically predetermined subtrahend, and adjusting the height from a floor surface to a pivot axis on the cart to equal the difference, said adjustment being effected by powered lifting means incorporated or ancillary to the cart.