Shower liner
Credit: Bob Kast / illustration

Dear James: The grout in my tile shower stall is a mess and I am tired of cleaning the grout.

Is adding a synthetic cultured marble liner a good idea and is the material very durable?

— Miles M.

Dear Miles: Tile is very durable, and most houses use it in showers, but most require regular cleaning to look nice.

Installing a cultured marble shower liner is a relatively simple project, and it is definitely easier to clean than tile and grout. You can just wipe it clean with a damp cloth.

Unlike plastic shower liners, cultured marble is mostly a natural product. It is made with polyester resin and about 70% real marble dust.

The marble dust creates its uniquely attractive “deep” appearance. The range of colors is endless.

It requires much less care than real marble and it costs much less.

The polyester resin, used to bind the marble dust together, is extremely durable and stain resistant. Almost all boat hulls are made with polyester resin, so it must be strong and waterproof. A clear final factory-installed gloss coat is the most common surface finish.

With cultured marble, cleaning your shower will be a breeze. Just wipe any dirt off the slick surface with a damp rag.

Do not use any abrasive cleaners, even one with “mild” abrasives. If your area has hard water, you can clean off deposits with white vinegar.

Although cultured marble is durable, it can be scratched and chipped, so don’t wash off your golf clubs in there. A professional repairman can repair the spot and buff it to a high gloss again.

If a very large area is damaged or a piece is actually cracked, it is not a simple repair you can make at home.

You will probably not find many major national manufacturers of cultured marble. Most are smaller local manufacturers that sell in a fairly limited radius around their plant. Your local kitchen and bath shops are some of your best sources to find local suppliers.

With all the small local manufacturers, you may find it difficult to compare quality, and the quality does vary. There is a trade association, International Cast Polymer Association, that certifies local manufacturers.

As always, select a company that has been in business for a long while and talk to past customers.

You will likely find it easy and fun to install the cultured marble yourself. It is somewhat like cutting out a dress pattern.

Clean off the shower wall thoroughly. If you plan to use light-colored cultured marble, paint the wall flat white. The color of dark spots on the existing tile can show through.

Cultured marble sands easily with a belt sander. No matter how well you measure, the shower walls are never perfectly square.

Scribe a line on the piece to mark it and then use the belt sander to remove the excess. It should be sized so that there is a ⅛-inch gap at the corners and where the pieces rest on the floor or tub.

Put in the back piece first and then the side pieces. It is easier to fit the side pieces later because only one edge has to line up properly.

Once everything fits, remove the pieces and clean all the dust off the back with a rag and alcohol. Use clear silicone caulk on the back of the pieces to attach them to the wall.

Use small wooden spacers in the corners and along the bottom to maintain the proper gap. Give it 24 hours to dry. Remove the spacers and fill in the gap with color-matched silicone caulk.

James Dulley is a mechanical engineer, an avid Do-It-Yourselfer and a nationally syndicated columnist with Email your questions to him at Here’s How. The opinions expressed are his own.