Bath Fixtures Now > Blog > How to Remove Silicone Caulk from Fiberglass Shower Stall
Written By: In: Blog

How to Remove Silicone Caulk from Fiberglass Shower Stall

how to remove silicone caulk from fiberglass shower stall

For over three decades that I have been a professional plumber, I have had lots of complaints from homeowners. However, one of the complaints that have stood out the most is how to remove silicone caulk from fiberglass shower stall.

No year has passed that I didn’t receive this complaint. And that’s why I have decided to address it once for all in this post. I believe that by doing so, I will be helping many more people who aren’t able to reach me directly.

The truth is that’s as a homeowner; if you don’t practice the right care and maintenance tips for your home, you will often develop challenges along the way. Whether it is with your AC systems, plumbing fixtures, or simply home appliances, proper care is important if you want to enjoy the best home efficiency.


Does This Care Apply to Your Bathroom?

Yes, it does. If you don’t take proper care of your bathroom, you provide an ideal breeding ground for mold and mildew. The edges of the tiles or bathtubs laid in the bathroom if not cleaned properly will form ideal nesting sites for mold and mildew.

This is because the connecting edges of bathroom fixtures harbor moisture. And moisture is the ideal catalyst for the spores produced by the mildews to thrive on.

How Do I Fix This Mildew Problem Now?

Once they start to grow, mildew can be very persistent. However much you try to fight them they will come back stronger. But the good news is removing them is not entirely impossible. By removing the silicone caulk that holds the fiberglass or tiles together and replacing with new ones, you can easily stop the growth.

It might seem literally time-consuming, but it is not. Many homeowners that I have advised to do that before having always come out with great results. This process is also an easy Do-It-Yourself plan.

So what’s the best way on how to remove silicone from bathtub? It is more or less the same as how to remove silicone caulk from fiberglass shower stall. Take a look.

How To Remove Silicone From Bathtub

How to Remove Silicone Caulk from Fiberglass Shower Stall?

If your bathroom has a fiberglass shower stall, here is a simple guide that will help you to remove the old silicone caulk.

But first, you must remember that it is important that you learn how to remove old caulk and how to apply the new caulk in order to prevent the growth mildew.

These tools and materials will come in handy:

  • Surface cleaner
  • Sharp knife or blade
  • Razorblade scraper
  • Rubbing alcohol
  • Vacuum cleaner
  • Bleach
  • Bucket
  • Water
  • A new tube of caulk
  • Piece of a damp cloth
Homemade Caulk Remover

Step 1: Clean the Tub/ Shower Thoroughly

Start by cleaning the shower or the tub thoroughly. Use a surface cleaner to help you remove the accumulated remove soap scum.

It is important to do this for one simple reason. It ensures that the surface you are working on is very clean so as to prevent any foreign substances from coming in between your new caulk and the main surface.

Step 2: Inspect the Previous Type of Caulking

You don’t want to mix caulk or use a low-quality caulk for your bathroom. Because of this, it is important that you check to see the type of caulking that was used on your fiberglass shower before and purchase the same.

Step 3: Remove the Old Caulking

Once you have the right type of caulk, it will be time to remove the old one. You cannot apply new caulk on top of the old one. Take a sharp knife or blade and use it to cut into the previous caulk to remove.

If don’t find a sharp knife or blade, you can always buy a silicone caulk remover from the hardware store. Commercial caulk remover is often faster and easier to use. Nonetheless, it’s up to you to determine the best way to remove the caulk.

Additional Tip

For silicone-based caulk, one can always use a razor blade scraper too. The other types can be warmed with a hairdryer before being scraped off. This doubles up with even a homemade caulk remover.

NOTE: As you remove the caulk, check if it is soft and rubbery. If it is then the caulk is a silicone based caulk. However, if the caulk is hard and kind of crumbly then that should make it a water-based PVA/ latex.

Step 4: Scrub the Areas You Have Removed Caulk From

Remember we said that every place you are going to apply caulk must be clean? Yes. This applies to even the areas where you have removed the old caulk. Use rubbing alcohol and clean the areas. It will help in removing any pieces and bits that might have remained stuck after you scrapped of the old caulk.

Step 5: Vacuum Remaining Pieces of Caulk

In case there are still other pieces of caulk remaining after you clean using the rubbing alcohol, you can vacuum them. Vacuuming helps to remove any caulk that might have remained stuck in between the tile, shower pan, or even the tub.

Step 6: Disinfect the Space to Kill Mildew

Now prepare a solution that can kill the mildew. For a homemade remedy, mix 10% of bleach and 90% of water and spray it over the area. This should easily kill the mildew and the mold that had grown.

Before you proceed, let the solution sit for about 5 – 6 minutes before you scrub down with clean water gain. Now rinse the area.

Step 7:  Let the Area Dry Up Completely

Once you have rinsed the shower area, you should allow it to dry before you apply new caulk. If you want the area to dry up properly, it is advisable to let it sit for at least 12 hours. After that, you can apply your caulk.

Step 8: Applying New Caulk on Your Fiberglass Shower Stall

The moment your shower stall is dry, it is time to apply new caulk. Follow this guide to get it right.

Step I: Use the Right Type of Caulk

If you are working on a ceramic floor or tub the best materials for your new caulk should be Acrylic and PVA.  This is because the caulk is pretty hard.

However, if you are working on a fiberglass fixture or surface a silicone-based caulk will be the best. This is because it is relatively soft after it actually dries.

Step II: Cut off the Caulk Tube’s Tip

Cut the tip of the caulk’s tube carefully. Making the hole extremely large will prevent you from controlling the caulk’s flow properly. A smaller tip, on the other hand, is easy to control and use too.

Step III: Squeeze Enough

Do not squeeze to much caulk on vertical joints. A small application of about 0.6cm should be enough for a joint application. With enough application, you will find a clean finish when you finally smooth out the caulk.

Step IV: Smooth the Applied Caulk

Now use the tip of your finger to smoothen out the new caulk so that it gets into the joint. This enables your finger to catch excess caulk that you will later wipe off using the piece of a damp cloth.

NOTE: Do the same for the horizontal joints too that are around the shower, fiberglass stall, or the tub.

Step V: Apply More on Less

If you can see places which look thin, there isn’t any harm to apply more caulk. Squeeze in and spread out using your finger before you wipe with a damp cloth.

Step VI: Leave the Caulk to Dry

Your job is done here. You can now give the new caulk some time to dry up and seal the joints. I recommend 24 hours or a little more before you can actually drain the water. You can then rinse the fiberglass shower stall area before you start using it again.

How to Remove Silicone from Bathtub: Tips that Help

There are a number of tips that will help you to get silicone out of your bathtub and fiberglass shower stall in the best way. They include the following:

  • If you are using a homemade caulk remover make sure the place is properly rinsed before applying a new one.
  • Always check and find out the type of caulk that’s best for your surface. For fiberglass, use silicone caulk always.
  • In case you have applied the new caulk on fiberglass, keep the area dry so that no moisture is locked in again.


How to remove silicone caulk from fiberglass shower stall is no brainer really. However, you need to have the right tools for the job and learn the proper way of using them. This should make your work easy and fast.

I recommend having all the tools and equipment that you will use to remove the old caulk and fix the new caulk first before you start the work.

how to remove silicone caulk from fiberglass shower stall - Image for social share!

About Robert Hellson

Robert Hellson

Professional plumber

Related Articles

Leave A Reply