Q&A / 

Cultured Marble

Cultured Marble TIPS

DEAR TIM: I'm really fed up with the constant care that my ceramic tile bathtub and shower surround requires. I'd love to have a single piece of marble on each wall.

I've not won the lottery, do you think the cultured marble products will suffice?

Will these synthetic products loose their shine over time? Is it possible for the average person to install cultured marble products? Can you repair pieces that are damaged? Mack T., Liberty, IN

DEAR MACK: Let's set the record straight before we go any further. Cultured marble is really not a totally synthetic product.

Real Marble Dust is Used

Real natural marble dust is used to make cultured marble. This ground-up marble dust accounts for over 75 percent of the volume of a typical cultured marble product.

The marble dust and liquid polyester resin form an attractive and durable bathroom and kitchen product.

I can attest to how cultured marble has rock in it because the sink and countertops made from it are quite heavy!

CLICK HERE to get FREE & FAST BIDS from local contractors who can clean and restore synthetic marble.

cultured marble

It's tough to see the veining in these giant solid sheets of synthetic marble. No grout lines make it easy to clean. Copyright 2017 Tim Carter

Marble Issues

It's important to realize, real marble can be a nightmare in a bathroom or kitchen environment. It's naturally porous and as such can stain easily. Hair coloring products, chemically reactive shampoos and conditioners, and many colored liquids can cause staining problems with natural marble.

Stain Resistant

High-quality cultured marble can withstand stains that might otherwise harm natural marble. The resin in the composite marble gives it this quality. This synthetic marble can stain so you don't want to be careless with any personal-care liquid or food item that's acidic.

History Of Cultured Marble

Another key point is the cultured marble industry is now quite mature and very interesting. It got its start in the late 1960's as a "garage" business. Small volume local fabricators sold their products to plumbing and building supply houses.

The industry continues to be quite fragmented and there are hundreds, if not thousands, of small companies who produce cultured marble all over the United States.

Quality Control

For this reason the quality of the finished product can vary widely from one manufacturer to another. Since the marble dust and polyester resin are mixed at the small factories, there can be errors or a fabricator may decide to use less of the most expensive ingredient to lower his costs.

Pro Association

Years ago, many of the leaders in the industry founded the International Cast Polymer Association. This group, at one time, had a certification process so consumers could tell what members made great products.

Certified members of the association are committed to making a high-quality cultured marble, granite, onyx and solid surface product. Cultured marble made by a certified manufacturer, should maintain its brilliance for many, many years as long as you care for it.

Many Products

Cultured marble can be used to create many bathroom and kitchen products. Sinks with integral tops, bathtubs, whirlpool baths, shower basins, back splashes, wall panels, etc. are all possible.

Since it's a molded product, manufacturers can create an infinite amount of designs tinted to any color. The clear finish can be ordered high gloss or satin from many manufacturers.

CLICK HERE to get FREE & FAST BIDS from local contractors who can clean and restore your synthetic marble.

Restoring Gloss

Cultured marble that has lost its shine can be restored by using Gel-Gloss or Counter Top Magic once a year. 


Here's a great polish for dull cultured marble. CLICK THE IMAGE NOW TO ORDER IT.

Repairing Scratches

It's possible to repair scratches, chips, and minor blemishes. A certified repair person can re-buff the surface with a special mixed gel-coat compound.

You can also use a DIY repair kit that can often make scratches or chips disappear.


This kit is Made in the USA and it says it's for marble. Any kit that says it will work on marble WILL WORK on cultured marble. If in doubt, contact the Cast Polymer Association for their best recommendation. CLICK THE IMAGE TO BUY THIS KIT NOW.

Cracks and broken pieces are virtually impossible to repair. It's not possible to apply a complete new clear finish to a cultured marble product once it's left the factory.

Install Tips

Installation of cultured marble tub and shower surrounds is really simple. The process goes quickly if the wall surfaces are plumb, square, and flat.

The walls behind the cultured marble should be flat white. Colored drywall or gray cement board can show through some light-colored marble products.

Dry Fit First

With this in mind dry fit each piece to make sure they are sized correctly. Remove dust from the back of each piece with rubbing alcohol before you apply clear 100-percent clear silicone caulk adhesive.

Three-Piece Tub & Showers

I prefer to start my installations with the piece that goes on the wall I face as I enter the tub or shower. If you install the side wall pieces first, your cuts on the final piece have to be perfect.

That can be tough for a beginner. Caulk all seams with a colored 100-percent silicone caulk that will closely match the cultured marble.

No Abrasive Cleaners

Cultured marble is easy to care for once installed. Avoid any cleaning product that contains abrasives. Use a squeegee after each shower to quickly remove water drops from walls.

Hard water deposits can be dissolved easily with white vinegar applied from a spray bottle. Apply the vinegar and wait for 45 minutes to an hour.

Rinse the softened deposits with clear water and a sponge or cleaning rag. Heavy hard-water deposits may require multiple vinegar spray applications.

CLICK HERE to get FREE & FAST BIDS from local contractors who can clean and restore synthetic marble.


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26 Responses to Cultured Marble

  1. I have a cultured marble shower enclosure. It is 19 years old and still looks great. However, every place that I have accessories held in place by small suction cups have left a round stain. Same problem in our tub where the tub mat was. How can these stains be removed?

  2. Could someone please help??? I had purchased my new home in January... 4 months ago and my shower is making me sick.. headaches, nosebleeds, etc. My husband and I noticed a small bead of black along the caulk on shower floor. He thought it was mold but knew otherwise when we looked closer. It was several holes in the caulk getting larger! My husband recaulked it, but the hole just kept getting bigger. He finally did it again and left the shower dry for several days before we got it wet. Weeks went by and I started becoming sick... I have severe allergies and sinus issues. I can smell mildew and it's getting stronger. He pulled out the piece that he caulked and what do u know? Mold n mildew behind the piece and along the backing. We thought it was one piece, but over the days my nose told me something different. He pulled out another piece and MOLD was on it and the glue!! Who do we call to fix this??? Do we order new cultured marble pieces??? HELP!!

    • Type: biofilm into my search engine NOW. You need to sanitize and CLEAN the gunk off the sidewalls of the pipe that extends from the shower drain you stand on down to the p-trap.

    • during and after you fix the problem the spores will still be in the air. I hired a restoration company and rented an air scrubber (filtration machine) that removes all spores and odors from the area. saved my health.

  3. Dear Tim, I currently have a fiberglass shower stall that has been leaking though the glass door seams. Ultimately producing some black mold. Besides getting rid of the mold, I am remodeling my shower and can't decide on cultured marble or porcelain tile. my daughter who works for a tile place swears by the tile. She says the marble is too heavy, very porous and requires resealing annually by a professional. My installer who use to work for a marble place swears by the cultured marble. He claims that the tile tends to leak more and it could be tough to keep the grout clean. Other than the usual biweekly/monthly shower cleaning (depends on how quickly the mold and mildew develop) , I am not one who likes high maintenance bathrooms. If I have to tear out my shower, I want to upgrade which is why replacing the fiberglass shower with another fiberglass shower is not an option.

    The pattern of choice (tile or marble) will be mainly white with some grey swirls running though it so if II go tile, I will need to use a light colored grout which I am told will require a lot of maintenance keeping it clean can be prone to leaking. If I go cultured marble I am reading horror stories about staining problems and having to reseal every year or two. I really like the idea of not using grout but my may concern here is the maintenance with either product.

    Can you provide any advise on which material is better to use and why from a maintenance standpoint? what are the pros and cons to using cultured marble vs porcelain tile? I never thought about the marble chipping so some of your points above added to my concerns about using marble.

    Thank you, Diane

  4. I have a old cultured marble bathroom sink that in the bowl it is really cracked... Is there anything I can do to restore or fix the cracks. It is really ugly!

  5. Depending on how handy you are you can repair it. I repaired a crack in a cultured marble bathroom sink. Colored epoxy with fill the crack and clear gelcoat (available from an auto store or a marine supply will replace the gelcoat. You can find detailed instructions on the internet.

  6. I love my cultured marble shower and bath, but have acquired a crack in the "custom" shower base. Is it possible to repair or resurface without totally replacing? It would be very expensive to have another custom piece made and could also involve our soaking tub, as well. Is there a possibility of an overcoat being poured on top of the existing floor?

  7. I have a cultured marble shower and love that it is easy to clean, but the floor is slippery despite the slightly raised pattern that is to keep this from happening. I am looking for something to apply to make it have traction, but won't ruin the floor. I have been told that etching solutions will break down the resin in the floor and ruin it - is that true?

  8. I have cultured marble tubs and we are having problems with both of them.. apparently they cannot withstand very hot water and have cracked from the hot showers we enjoy. Now they are leaking. Does anyone know anything about this?

  9. I tried gel gloss on my dull cultured marble counter top and it was totally useless - just to save someone the $ and time - if the shine is gone that won't put it back. Going to try automotive rubbing compound and wax next. wish me luck..................................

  10. Shortly after we moved into our home, there was a leak under our jetted tub. We called someone out to fix the leak but they had to remove the cultured marble front. They did not put the front back on the tub, trying to get it to dry out. During that time, it was left leaning against the end of the tub and the cultured marble bowed. Is there any way to straighten it out or must we purchase another panel?
    Thank you,

  11. We are remolding a small bathroom. We have a neo angle shower. I would like to tile the walls and possibly tile the floor. It is an upstairs bath, so I want to be careful about a possible leak. What do you think would be safe for the base? I also would like something that is easy to clean, little or no maintenance. Thank you.

  12. The previous owners of our house painted over the cultured marble shower, tub, and vanity. The paint is peeling now. Can I just take off the paint and go back to the existing shower? What could I use to remove the paint? Is it possible to tile over the cultured marble without taking the whole shower out? Please help-it looks so bad!!

  13. We love the solidity of the cultured marble counter and garden tub in our master bath, but the green color is awful! Is there a brand of tub paint you would recommend? (Replacing the large tub is not $$ feasible.)

  14. We have a brand new home with cultured marble countertops in our bathrooms. In one bathroom I noticed after just a few days there were water spots that wouldn't just wipe up. I sprayed vinegar on the area, waited for a half hour or so and then wiped up. Now that whole area has lost it's glossiness and is completely dull, like the vinegar ate through the finish. I am so surprised and dismayed and don't know what to do. Any helpful suggestions?

  15. Dear Builder--

    I have a swirled, cultured-marble sink vanity that had a couple of large round burn marks. I asked a resurfacer to coat the surface white. Apparetly, they use a polyurethane product to do so. Unfortunately, they have tried recoating the surface three times now, and we see dimples in the coat itself arise in different locations depending on the coat. The resurfacer tells me that cultured marble tends to trap air bubbles and maybe willing to give a refund. Can you please explain what is happening and what my alternatives are to remedy the situation? Giving a refund does not solve my problem.

    Thank You.


  16. we also have a cultured marble shower which after 4 years has acquired a crack that is not all the way thru the wall. I have been told pretty much sorry about your luck by the installer??!! It occurred on the wall with the shower head and it is approx. 6 inches long in the middle of the wall at least 10 inches down from the turn on spigot. NOW WHAT should we get a repair kit and try to fix ourselves?? We are guessing that the wall was compromised when installed??

  17. Hi. I need some advice. I just had my cultured marble shower pan replaced. The problem is that it never dries. It holds little pools of water for days - we tested it. Manufacturer says it’s normal, but it never happened with our previous cultured marble pan. Please help!

    • So easy. Buy a small squeegee. Turn of the shower water. Squeegee the walls fast. Bend ofver and squeegee the floor.

      Not only will water disappear, you'll lessen the chances of mildew growing.

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