How to Plumb a New Bath Tub

Step by Step Instructions for Plumbing in a Bathtub

By Mark J. Donovan

If you have ambitions of installing and pluming in a new bathtub you’ll need a few basic household tools and couple of hours of time. To simplify your effort and time plumbing a new bath tub, there is a certain sequence of instructions that you should follow. Summarized below is a set of instructions and a prescribed flow on how to plumb a new bath tub.

Prior to placing the new bath tub into its final position connect the taps, and overflow and drain pipes to the tub.

The reason for this is that once the tub is put into position up against a couple of walls it becomes extremely difficult to work in such a tight space.

Second, attach some adjustable feet, e.g. plastic shims, to the bottom of the bathtub so that you can adjust the height of the tub so that it is at the desired height and it is level. Make sure to check along the length and width of the bath tub to ensure that it is level. Once you’ve placed the tub into position and it is level, connect the bathtub drain pipe to the P-trap located in the floor.

Then fasten the tub to the surrounding walls by attaching the metal hardware fasteners to the tub lip and the wall studs. If metal fasteners were not provided, then attach the tub to the walls by nailing in galvanized nails (e.g. roofing nails) into the wall studs just above the tub flange, such that the nail shaft sits just above the tub flange. This way the roofing nail head will hold the tub flange flush to the wall.

Installing the Bathtub Faucet Taps

Whether you have a single mixer type or separate hot and cold taps there should be a large sealing gasket that should go over the taps and abut up against the tub wall.

Escutcheon plates, or metal covers, should then be positioned over the sealing gaskets and then secured to the tub with the appropriate nuts and washers, or screws, depending upon the type of bathtub faucet you purchased.

Installing the Waste Outlet and Overflow

First apply a bead of silicone caulk or plumbers putty around the rim of the overflow outlet in the tub. In some cases a rubber seal may have come with the waste outlet hardware. If so, use this instead of the caulk or putty.

Then slide the tail drain assembly into the overflow hole, and fasten its cover plate to the tub using the screws/bolts.

Similarly attach the waste drain trap to the base of the bathtub, again first applying silicone caulk or plumbers putty around the rim of the drain prior to fastening the drain cover to the tub.

Caulking the Bathtub

Finally apply a bead of silicone caulk around the escutcheon tap cover plates and overflow drain cap area to prevent any water from seeping in behind them.

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