Installing a bathtub isn’t an easy do-it-yourself project because it involves working with a large, heavy object in a small space. If you have any misgivings about doing it, hire a plumber who has the experience to install it and the license to hook up the fixtures.
If you want to do it yourself, inspect the new tub before you start the installation. Measure its dimensions and check them against the size of the opening. Make sure that the drain outlet is at the correct end of the tub. Look for signs of damage, and then protect the tub surface with a dropcloth.
Before you get started on the installation, inspect the floor joists and look for joists that have been weakened by rot or were cut to remove pipes. Remove a rotten joist and replace it. Reinforce a bad joist by fastening a new joist to the existing one with machine bolts. Then install a new subfloor over the joists if necessary.
Such work is beyond the capabilities of most DIYers, so don’t hesitate to hire a carpenter if you run into situations that seem like more than you can or want to handle.
Gather the following tools and materials to install an acrylic or platform tub.
1-inch galvanized roofing nails
2 x 4s
Carpenter’s level
Construction adhesive
Electric drill and bits
Measuring tape
Mortar mix
Pipe wrench
Plumber’s putty
Screwdriver
Silicone caulk
Trowel
Wood shims
Woodworking tools
An acrylic tub is set in a bed of cement — check the manufacturer’s recommendations. The sides are screwed or nailed through flanges into wall studs. The tub is supported on a 1-x-4-inch ledger nailed to the wall studs. In models with integral supports under the tub, you can shim under the supports to compensate for a slightly out-of-level floor. Then you connect the overflow assembly to the tub drain and main drain line, connect faucets to the water supply lines, and hook up plumbing pipes and drain lines.