Can You Cement Over A Fiberglass Shower?

Are you planning to cement your fiberglass shower? What could be the result of doing so, and how to do it? We've researched the answers just for you.

Yes, cementing over a fiberglass shower will change the shower floor's texture. Doing so can also add thickness to the surface and make the floor stronger. However, there are a few things to consider before doing it:

  1. Drainage
  2. Floor Area
  3. Floor's Quality

Throughout this article, we'll learn the process of applying cement over the fiberglass shower floor. We'll elaborate on the possible results, as well as discuss other relevant topics. So, let's keep reading!

Can You Cement Over A Fiberglass Shower?

Luxury apartment, modern bathroom with round mirror

Yes, you can cover a fiberglass shower floor with cement to make its surface rougher. You can either put cement on a specific portion of the floor or on the entire floor.
However, it's important to understand what are things to look for before cementing your fiberglass shower. 


Since pouring cement can add thickness to the floor, it can affect the redirection of wastewater. You should make a downward slope allowing wastewater to gravitate toward the drain. Otherwise, puddles of shower water can gather on floor corners and edges.
Also, some homes have a shared drain between the shower room and the laundry room. If this is your case, you will want to ensure that the wastewater will reach the drain successfully.

Floor Space

Narrow floor space is quite difficult to renovate. Prepare other areas for cementing the shower floor, such as  wrapping some old newspaper, plastic, or a drop cloth around the toilet. This protects the toilet in case the toilet and shower are both in one area.

Floor's Quality

Of course, you should check the fiberglass flooring quality. Inspect for any damage or mold growth. The floor's quality can affect how the concrete will adhere to the surface. Damage and dirt can interfere with cement adhesion.

If there's empty space beneath the shower area, then adding cement can weigh down the floor. So, check also the ceiling below the adjoining shower area to ensure the structural strength.

Cons of Concrete Shower Floor

shower in bathroom close up gelcoat modern oange style

To further assess the shower area, we're giving you some results you can expect, as well as important considerations. So, see the list below.

Resistance to Heat

Cement is good at resisting extreme heat compared to other building materials. However, this doesn't guarantee complete fire resistance to fire. The layer beneath the cement can still burn and trigger other layers to burn as well.


Although durable, cement will crack over time. You should expect this to happen after a few months or years, especially if the mixture isn't consistent enough.

This also means that you should ensure the quality of cement to use. A substandard cement product will wear or crack too early.

How to Properly Mix Cement

It's important to know how to mix cement for this project. Consider checking the steps below:

  1. Prepare the cement, sand, and stone. The ingredient ratio can vary depending on the cement type; typically, you can refer to 1:2:4 of cement:sand:stone.
  2. Wear gloves, and cover your nose with a mask as well.
  3. Mix them together, then add a small portion of water first. This is to test the quality of the cement before pouring more water.
  4. Test the cement by putting it somewhere outside the house. Wait for a few minutes until it gets dry.
  5. If the cement's quality turns out good, then proceed to the next step. Otherwise, consider finding a better cement product.
  6. Now, add more water to achieve a good consistency.
  7. Mix well, then apply to the surface.

How to Cement Over A Fiberglass Shower Floor

There are two ways of applying cement over the fiberglass shower floor. One is to apply a small portion to repair specific damage, and one is to convert the entire floor into cement. Either way, the steps are still similar. 

  1. Clean the floor by scrubbing off the dirt and stains. Allow the floor to dry.
  2. To avoid overspilling the cement, outline the shower floor with a nylon string.
  3. Put a cover on the drain to prevent blocking it.
  4. Tape some old newspaper on the wall and around the toilet to prevent the cement from adhering to them.
  5. Mix the cement, sand, and water in a pail.
  6. Use a trowel to spread the cement. Make sure to make a downward slope around the drainpipe for the proper drainage system.

Can You Tile Over Fiberglass Floor?

Aside from cementing the fiberglass, you can also install tiles on top of it. However, you need a strong adhesive, such as thin-set mortar to allow the tiles to settle in place. If you want to do this option, simply follow the steps below:

  1. Clean and dry the shower floor.
  2. Cover the drain.
  3. Prepare the mixture of thin-set mortar. It usually contains fine sand, cement, a retaining agent, and water.
  4. Apply the thin-set mortar throughout the floor area.
  5. Use a notched trowel to make some lines across the mortar.
  6. Before the thin-set mortar gets hard, place the tiles on top of it.
  7. Make sure to shake the tiles a bit for proper adhesion.
  8. Install all the tiles. It's a good idea to pre-size and cut any edging tiles for a proper fit.
  9. Allow the tiles to adhere for at least a day.
  10. Next, splash some water over the tiles, then scrub off the thin-set mortar with mild soap. Wipe the floor to let it dry.

Is Fiberglass Shower Floor Slippery?

Contemporary marble bathroom shower and spa in white

Yes, fiberglass becomes slippery when in contact with water, especially when used on a shower floor. The soap or other personal hygiene or cleaning products can make the floor even more slippery.

However, there are some ways to make a fiberglass floor less slippery. Check below the options.

Interior of stylish bathroom with wooden walls, concrete floor, double sink with horizontal mirror and shower stall, Can You Cement Over A Fiberglass Shower?

Install a Rubber Mat

Rubber mat has the ability to resist movements in wet areas like a shower. You can simply lay it on the floor like a carpet. This is a quick solution, as you can even remove the rubber mat when needed.

See this rubber mat on Amazon.

Use Anti-Slip Tape

An anti-slip tape is commonly used on stairs to prevent slipping accidents. You can also use it on shower floors. Simply measure and cut the tape, then adhere it to the spot where you usually stand in the shower.

See this anti-slip tape on Amazon.

Install a Handrail

A hand bar or handrail is a safety tool you can mount on the shower wall. This helps you from slipping by simply grabbing it when the floor is too slippery. Most hand bars just need screws for mounting, which you can do in less than an hour.

See this hand bar on Amazon.

Can You Paint Over a Fiberglass Shower Floor?

Yes, you can paint the fiberglass shower floor using primer and waterproof enamel (typically lacquer- or oil-based). 

To proceed to paint the fiberglass shower floor, simply follow these steps:

  1. Dust off (clean thoroughly, as needed) and dry the floor.
  2. Lightly sand. Wipe away dust.
  3. Repair minor damage with a patch seal.
  4. Put some tape along the shower's edges and corners to protect the wall surfaces.
  5. Prepare and mix the primer according to product instructions.
  6. Apply the primer to the floor.
  7. Let the primer dry before applying the enamel paint on top of it.
  8. Spread the enamel paint evenly on the surface.
  9. Allow the paint to get dry, then remove the tape you put on the wall.

How to Remove Cement From Fiberglass Surface?

Shower stall and bathtub inside a clean bathroom with brown tiles on the floor

If you accidentally poured cement over the fiberglass surface, there's a way to remove it. There's actually a product used to dissolve the cement. It's a concentrated solution strong enough to eliminate even hard cement on the surface.

See this cement dissolver on Amazon.

Refer to the steps below on how to use this product:

  1. Apply the dissolving solution to the cement.
  2. Wait until the cement gets soft, so that you can smash it with a hammer or scrape it off the surface.
  3. Use a brush to completely remove the cement.
  4. Check if there's damage on the fiberglass floor. You'll want to repair it with a patch seal or paint.
  5. Ventilate and clean the area to eliminate odor.


Now, you're ready to cover your fiberglass shower floor using cement. Remember to begin with a clean, undamaged, structurally sound floor for best results. Protect the drain from cement, and create a gradual slope in the floor for adequate water drainage.

Are you ready for more to read? Join us in reading here:

How Thick Should A Concrete Shower Base Be?

What Mortar Or Concrete Mix For Shower Pan?


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