We’re also using fiber cement trim boards. Since they’re only 7/16 inch thick, rip 3/8-inch thick strips from treated 2-by lumber and use them to fur out the frieze boards. Now they’ll sit ...

drywall screws spaced every 6 in. Use 1/4-in. thick cement board instead of the usual 1/2-in. cement boards that some in sheets. That’ll keep the floor thickness to a minimum.