Installing separate 3/4-inch lines to supply the shower ensures good water pressure and protects from temperature changes when another faucet is turned on or the toilet tank refills. Tap into the cold and hot water lines as close to the water heater as possible.
Choose the tub or shower faucet before you run pipes. Follow the manufacturer's directions for plumbing the faucet. If your faucet does not have integrated shutoff valves, install shutoff valves in the lines to the valve.
Assuming an 18-inch-tall tub, position the faucet about 28 inches above the floor for a tub, about 48 inches for a shower. You may want to compromise and position it about 38 inches above the floor.
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