Inman

Tips on prefab shower installation

Q: We are looking to put in a walk-in shower. It will be new construction. Several folks have told us it is a major pain because we’ll need to cut joists and lower the drain.

However, we’ve come across a product called Tile Redi that looks as if it would be much simpler. Do you have any experience with that or similar products?

A: Yes, we do have experience with similar products. And the folks telling you about cutting away floor joists to lower the drain are full of baloney.

We checked out the Tile Redi website. From what we see, it’s a standard shower pan with a built-in drain, but with one big difference: True to its name, the finished product is not plastic. It is made to take a tile floor. Other than the beefed-up material and finish, though, it seems to be pretty standard.

Prefab shower pans have been around for years, and we have a good deal of experience with them — both in new construction and in retrofits. Pans are made of molded heavy-duty plastic or metal. High-end models are finished with terrazzo, which is crushed marble. They are available in a variety of sizes, from 34-by-34 inches on up to 36-by-60 inches and larger. Drains are located either left, right or center.

In Bill’s Alameda, Calif., Craftsman, we installed a 36-by-54-inch terrazzo model. In Kevin’s Second Empire Victorian, he opted for a 36-by-48-inch heavy-duty plastic model. Neither of these installations required cutting floor joists or lowering the drain. Kevin put in a 36-by-60-inch shower pan in his master bath when we built his home in Idaho. No reconfiguring the floor joist here, either.

Because your project is new construction, the floor framing should be designed to accommodate the shower drainpipe. In new construction, most likely the floor joist will be made from engineered wooden I-beams. If it turns out the joists need to be crossed, a 2-inch hole (the size of the pipe for a shower drain) can be drilled in the middle of the joist without compromising its structural integrity.

A word of caution: If you decide on the Tile Redi pan, make sure you, your architect and your contractor follow the manufacturer’s specifications and instructions. The flexion of the subfloor must be well within the manufacturer’s recommended tolerances. Any less and you risk cracked tile and grout.

One of the problems with metal and plastic pans is that they can bounce when occupied. Neither of us is small, and there’s nothing more irritating than to feel the earth move underfoot while taking a shower. We solved the problem by setting all of our shower pans on a bed of wet mortar. They are rock solid to this day.