Should You Caulk Or Grout Shower Corners? (Choose This!)


Having a new shower in the house increases life’s pleasures every morning and adds dollars to the value of your home. However, details matter, especially when we know to check how well or badly the contractor finished the shower corners off. 

Would you be surprised to know the average American homeowner could do at least as good a job when they know how? It’s true! We explain the details, and we share trade secrets you need to know. But which is the best method to seal the inside corners of a shower?

The correct solution is often a combination of silicone and grout. Silicone works best on smooth surfaces like anodized aluminum and vinyl shower floors. However, it does not adhere well to ceramic tiles; that’s where grout is superior. So, you may have to use silicone caulk for some shower joints and grout for others, depending on the surface.

What Is Silicone Caulk And How Do We Use It?

Silicone caulk is an adhesive well suited for closing joints. Silicones for bathroom applications should be highly resistant to weather, temperature, water, and chemicals. They stay flexible, elastic, and stable after application.

Silicones, generally speaking, take one to three days to cure, depending on the thickness of the coat. 

It’s possible to smooth them with a fingertip moistened with soap during the first minute, before a skin forms. After that, silicone is best left alone to dry.

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Working Safely With Silicone – A Basic Guide

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Silicone emits fumes when first exposed to the air that could irritate sensitive eyes. Working all day long with it in an enclosed space could lead to dizziness. 

Always open the windows before you start. Avoid touching your face and eyes during application. Wash your hands thoroughly when you’re done, even if you have worn gloves.

Keep the product away from kids and pets. 

What Is Grout And How Do We Use It?

Grout is very different from silicone, which comes ready to use in a tube. It is a mixture of cement and sand with a hardener added and usually comes in a packet in dry form. 

Before application, you must mix it with water until it becomes a thick paste that can be applied and formed.

Grout, like silicone, is available in a variety of tints to match surrounding areas. It remains workable for an hour or more after mixing. Closing a gap or smoothing an inside corner with grout is, therefore, more leisurely done than with silicone.

Working Safely With Grout – A Basic Guide

However, grout does also carry a slight health risk. Being a cement product means it is dust that could enter your lungs if you breathe it while still dry. 

Wear a face mask when you mix it and gloves when you use it because it is alkaline and mildly abrasive to the fingertips.

Deciding Whether To Use Grout Or Silicone Inside A Shower

We really have only two choices for sealing shower joints, unless we want water leaking past the door frame and pooling on the bathroom floor tiles outside. Our options are:

  • Caulk the joints with a tube of silicone using a handy applicator
  • Seal the joints with the cement grout we used between the tiles
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When to Use Grout

Grout is a cement product. This means it adheres to porous surfaces like the backs and edges of tiles. It should not stick to smooth surfaces. 

Therefore, you should not use grout to seal joints between anodized shower cubicle partitions and where these meet vinyl or other smooth shower floors. 

However, grout is ideal for tiled shower trays, especially on the inside, where it is perfect for rounding corners.

When to Use Silicone

Silicone is a polyvinyl-type product. As such, it adheres almost like glue to anything that’s non-porous and smooth. 

Silicone is, therefore, ideal for caulking joints between anodized shower partitions, between these and PVC floor trays, and around toilet bases.

However, these are all high-profile areas where the eye falls naturally. You’ll improve their appearance if you lay thin adhesive tape on either side of your caulk line, smooth it over while it’s still wet, and remove the tape carefully, pulling it to one side. This would provide a smooth finish.

Re-Caulking And Re-Sealing An Old Shower

Perhaps you already have a shower, but the caulking has gone black with mold, and you want to remove the unsightly seal and apply it again. 

Before you do that, know that you may have some success cleaning it with an ammonia spray. However, ammonia can’t help you much if the mold has penetrated behind the silicone caulk or into the grout.

If that’s the case, then you’ll have to put your materials to one side and get rid of the old sealant first. You have to thoroughly clean it away if you want your shower to look sparkling clean again. Especially if you want to use a different method this time.

How To Remove Old Caulking Sealants

Silicone, as we said, is glue, and it does its job well. Here’s what you have to do to get rid of it:

  • Use a sharp knife to score along both edges of the silicone. Use a flat screwdriver or an old chisel to peel the worst away.
  • Use a plastic spatula to work away at what’s left. Keep on at this until you have removed all thick residues and chunks.
  • Open the windows, put on eye protection and a face mask, and soak an old cloth in methylated spirits. 
  • Rub away at the remaining silicone. You’ll see bits of the material flaking off. Continue until every scrap is gone.
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How To Remove Old Grout

Grout is a cement-based product. You won’t need a jackhammer to remove it, although the principles are the same. 

Choose a suitable flat screwdriver or old chisel and a light hammer. Chip the grout out gently. Mind you, pay attention not to crack a tile in the process.

How To Apply The Caulking Or Grout You Chose

The job should go quickly after you researched the right sealing material for your job. 

It always pays to plan ahead before you start any DIY task. The old folk used to say it’s a matter of “measuring twice, cutting once,” or words to that effect.

Apply silicone sealant with a caulking gun, holding the tip of the tube at a 45-degree angle against the surface. Smooth the bead with a gloved or wet finger and remove the surplus. 

To apply grout, pour the prepared mixture into a squeeze bottle and apply a bead along the joint. Smooth it with a gloved finger or a caulking tool. 


You can use either caulk or grout in the shower corners, depending on the material. Silicone caulk is the best choice for non-porous surfaces, such as PVC or anodized shower partitions. Use grout to seal joints between a ceramic shower pan and a tiled wall or floor.