Why Does My Bathroom Caulk Keep Cracking?


Why Does My Bathroom Caulk Keep Cracking?

There are several numerous reasons your bathroom caulk might keep cracking.

Your Bathroom caulk is cracking because of the wrong caulk, too wide for the kind of caulk used, application of caulk when the temperature is below 40 degrees F, the house settling, applying caulk over the top of the existing caulk, and improper application of the caulk.

While this is not an exhaustive list, it will give you an idea of the pitfalls you can avoid and ensure your bathroom caulk does not crack. Taking a closer look at the above list is precious.

We have two types of caulk that can be used in the bathrooms, including silicone and acrylic (latex). There are pros and cons associated with either of the two.

However, you need to use the correct one for the job at hand.

For instance, when working in the bathroom, you will need pure silicon because it’s a durable caulk that withstands bathroom mold and mildew.

It won’t adhere properly if the old caulk is applied when temperatures are below 40 degrees F. Caulk is temperamental, most having a range in which they can be used.

On the other hand, the newer calk should not be applied over the top of the existing caulk. Doing this is almost a sure way of ensuring that the caulk will not adhere properly.

And if the house is set, do not apply caulk since gaps always form after the house settles. Still, if there is too wide a gap for the kind of caulk used, there will be cracking.

This is because the caulk will find it hard to form a proper seal.

Can You Put Caulk On Top Of Grout?

Yes, But it’s not always a great idea. Although people confuse grout with caulk, sometimes thinking they are the same, there are vast differences between them.

There are situations where re-grouting will be better than applying a layer of caulk.

However, it all depends on your current project, as some projects will prove that layering with caulk is the superior choice.

From a general standpoint, it’s agreeable that caulking over grout is not a great idea.

Aesthetically speaking, it scarcely works out well, although there are practical reasons why caulk doesn’t fit as the appropriate choice for sealing or connecting two materials.

You will agree that caulk is the best material when making small connections. I am referring to connections like connecting your shower wall tile with the top of the bathtub.

But if replacing the grout connecting the bathtub to the floor, your best bet is re-grouting it. This is the same case when filling the space between two tiles or stones.

And if this doesn’t make one of the options, it is best to scrape out all the grout and replace it with caulk instead of placing it over it.

Should You Use Grout Or Caulk Around A Bathtub?

When renovating a bathroom, many people will easily be undecided and unsure whether to use caulk or grout.

The choice of either of the two to fill in the joints between your new tiles might be overwhelming, but you need first to understand that these two have different uses.

It’s indisputable that they are similar materials, but using one instead of the other is never wise.

Caulk is flexible as it is a product of polymers (e.g., silicone, latex, rubber). Consequently, it helps absorb movement.

On the contrary, grout comes from a mixture of water, cement, and sand.

You will agree that such materials are brittle, scarcely qualifying as a flexible product. This makes it harder than caulk.

Being waterproof and flexible, caulk is often used for corners around bathtubs (or around showers, windows, and other ledges) and tile joints.

And showers, windows, and other ledges.

On the other hand, grout lacking such waterproofing capabilities is mostly used for tile joints in backsplashes, walls, flooring, and tiling projects not having 90-degree angles.

When it comes to application, grout and caulk are applied very differently.

Grouting tile joints requires you to spread it all over your tiles with a grout float, pushing the grout into the crevices.

After setting, you must wipe the excess with a sponge until all the residue is gone.

The application of caulk is by a caulking gun. You need to cut the tip of the caulk cartridge to the desired size and put the cartridge in the gun.


Use it to seal your tile joints by squeezing the caulk between them. Smooth down the caulk with a smoothing tool, or use your finger before the caulk dries.

Why Did My Grout Crack When It Dries?

Grout tends to crack after application. While this is generally because of its properties, cracking can be eliminated if we understand the causes of such cracking.

The grout might crack after drying due to too much water, adhesive, improper pressing, quick cleaning, thin line, and calibration.

The most common reason your grout might crack is too much water, which brittle the grout mixture.

Water should be applied slowly and in small bits until you are content with the mixture. Alternatively, you can buy pre-mixed grout, although this might limit you to particular colors.

On the other hand, if you use little adhesive on the tiles, your tiles might be shaky, leading to grout cracking.

Still, if you do not press grout well when applying, it might lead to cracking. But this is a rare occurrence. Such cracking comes from air bubbles that will lead to cracks.

And if you wipe the surface on which grout has been applied too soon, you will be making a recipe for grout cracking.

Avoid cleaning the surface too soon after grouting. Again, grout might be strong enough if the lines between the tiles are thin.

Small spaces mean there won’t be sufficient grout to stick to both edges.

Regarding calibration, cracks might appear even if your grout is in super condition. These can be caused by poor surface leveling, among other issues.

How Do You Fix Hairline Cracks In Shower Grout?

The first thing to get rid of the unsightly bathroom tiles that have cracked grout is to carry out an inspection.

Without examining the entire shower unit, you will be unable to identify every instance of cracked grout needing repairing.

Use a little masking tape near each to prevent losing track of it. This is the best way to determine the best appropriate method of repair.

After inspection, have the tools you need ready for the task. You will want to repair it with the correct shade. Proceed to remove the cracked grout using a grout saw.

Be keen to avoid damage to the surrounding areas/tiles and wipe the resulting dust using a brush to work on a clean surface that is needed for the grout to stick.

This will be followed by mixing the grout in a clean bucket, following the manufacturer’s instructions.

The newly mixed compound should be applied to the holes from the old removed grout. Smooth the grout using a putty knife.

A dampened finger can also be handy in smoothing out the grout.

Should You Caulk Over Grout In A Shower?

Yes, caulking over grout in a shower is one of the options that might work for you. But this is never the best thing you can do.

I do not recommend caulking over grout in a shower, as it quickly leads to molds between layers. I understand that people prefer using this because it is a cheaper alternative.

Sadly, it has far-reaching effects that might be expensive in the long run. So, you might not want to caulk over grout in a shower.


When you notice cracks in your shower, the first temptation that hits your mind is to cover them up with another layer of grout.

However, this doesn’t seem right as it will not bond well with the old grout. This will result in peeling in between the caulk and grout.

This predisposes your shower to the risk of growing mold and mildew. Therefore, you want to remove old grout in the shower before refilling them with silicone caulk.

Indeed, this gives a professional, long-lasting seal. But you will need first to choose the right kind of caulk.

Does Vinegar Hurt Epoxy?

Yes, vinegar can easily hurt epoxy grout. However, some people have used vinegar successfully to clean epoxy.

Epoxy can sometimes be hard, if not almost impossible, to remove from surfaces. Some people have successfully used vinegar to clean epoxy.

Unfortunately, most people swear by the heavens that they cannot use vinegar with epoxy due to their experience with the two.

If you want to use vinegar on epoxy successfully, mix vinegar, water, and dishwashing liquid and put it halfway on a spray bottle.

Use the solution by spraying it over the grout. You will then need to use a soft-bristle scrub brush and ensure the grout is cleaned.

But if you want to remove epoxy from a surface, use some chemicals like muriatic acid and steel wool. These can never disappoint when it comes to removing epoxy grout.

Does Epoxy Grout Prevent Mold?

Yes, Epoxy grout prevents mold. Epoxy grout is different from cement-based grout. The latter is largely made of cement powder dissolved in water.

On the other hand, epoxy grout consists of filler powder and epoxy resins. This product is hailed for its durability.

Unlike other types of grout, it doesn’t soak up water. In addition to this, epoxy grout doesn’t retain dirt residue.

With epoxy grout, there is no deep grime in the tile joints to deal with.

Areas that have high humidity levels make for the best places for epoxy grout to be used. These include steam, wading, swimming, and shower rooms.

Since tiles require protection from water damage (no matter how tightly set), epoxy is what you want to use as it gives this protection.

Indeed, epoxy will seal the tiles’ joints, an action necessary to prevent mold growth and mildew attracted to moist places.

And epoxy, as already stated, comes in handy in areas with high humidity – powder rooms, kitchens, shower rooms, and bathrooms.

How Do You Smooth Out Caulking After It Dries?

While it is extremely easy to work with caulk (smooth) when moist and wet, it is a different story once it dries. 

Hard caulk is not easy to smooth by any standards as it gets hard and dry. However, having the right knowledge will help you smooth caulk in simple steps.

These steps will help you fix dried caulk that was too mean on you and dry it before you have finished smoothing.

A utility knife and sandpaper are treasured here to help fix uneven and jagged caulk to create an attractive surface.

Moreover, you do not require prior knowledge to get appealing results.

Why is my hot tub gurgling?

The first step is cutting and cleaning any elevated areas of the dried caulk. Be careful with the knife to prevent cuts into the wall or, worse, cuts on your skin.

A clean cut will demand a sharp blade. After this, use a piece of coarse sandpaper to smooth the surface.

Start with coarse sandpaper to remove larger chunks from the bumpy dried caulk. Later, use fine sandpaper to smooth the final product.

Use the sandpaper to rub vigorously along the caulk line and finish by using a new piece of extra fine sandpaper to lightly go over the caulk, making it even and uniform.

Can You Sand Caulk After It Dries?

Yes, you can still sand caulk even after it dries. Although caulking is necessary when sealing gaps in joints and woodwork, it might get messy without appropriate skills and knowledge.

Luckily, sanding caulk is a good solution in this regard. If the caulk is not made of silicone, it is easy to sand even after it dries.

Generally, you do not want to sand caulk when it is wet. Doing this ruins the integrity of your filling work, and you might be forced to start over again.

Although caulk might be tricky to sand when wet as it looks smooth, it gets jagged after it dries. When sanding dried caulk, remember that you should never sand decorator’s caulk.

One thing to understand is that you can’t sand wet caulk. If you do this, you will ruin your caulking project and your sandpaper.

Therefore, ensure it dries up completely before beginning the sanding process.

Can I Use Windex To Smooth Silicone Caulk?

Yes, you can use Windex to smooth silicone caulk. You only need to spray Windex on the silicone caulk you want to smooth.

Since silicone does not stick to Windex, you can proceed to tool the joint and wipe off the excess.

When smoothing silicone caulk with Windex, you need to apply enough silicone caulk before spraying it with Windex.

After this, use a tool like a scraper to eliminate excess caulk. As I have mentioned, Windex does not stick to the silicone, so you will smooth it evenly.

Silicone caulk is an adhesive sealant used for many professional and household applications.

Silicone caulk is highly resistant to chemicals, weather, water, and temperature. This is what makes it an appropriate product for outdoor use.

 Are Decorators Caulk Sandable?

No, The decorator’s caulk is not sandable. Indeed, this distinguishes Polyfilla from decorators caulk as the former is sandable and drillable.

Consequently, many homeowners will prefer it for filling walls. The decorator’s caulk comes in tubes, applicable using a caulking gun.

It is appropriate for application on the tops of skirting boards and door architraves.

Fortunately, decorators’ caulk is more flexible compared to filler. Consequently, it won’t crack in areas where little movement is expected.

Since decorators caulk suffers from shrinkage and won’t be sanded, you don’t want to use it on walls.

As you already know, caulk is easy to smooth when moist and wet. However, it would help if you prepared for challenges once it dries.

While some types of caulk can be sanded, others, like decorator’s caulk, are not sandable. Therefore, if you must use it, you will need to smooth it while it is still wet.

How To Fix Gap Between Toilet And Wall

When installing a toilet, you might notice a gap between the toilet and the wall. This is despite trying to measure everything and setting it up.

This can ruin the look of your bathroom. In addition, the toilet might even fail to flush the wall.

So you will need to measure the distance and cut a piece of wood, wedging it into the gap. After this, it will be a good idea to paint the wood to match everything around it.

But there are other solutions.

If you do not want to use wood to fix the gap between your toilet and wall, you might want to count the cost of removing and re-installing it afresh.

This might call for some purchases as the toilet might not even be the correct size. Therefore, unless the gap is substantial, there is no need to worry about it.

Indeed, if we are talking about a gap, not more than 2 inches, I recommend you ignore it. The toil is not worth the reward.

Who will notice a 2-inch gap anyway? Even buyers will overlook it!

Why Does Caulking Crack After Drying?

There are several reasons caulk might crack after drying. At the top is using poor-quality caulk. Not all qualities of caulk will flex and stretch.

Poor-quality caulk will hardly stretch and flex, so it will harden and lose elasticity as time goes on. This will be the beginning of unending cracking.


Poor workmanship on your bathroom caulk will lead to cracking.


Hi! I' am Tom. I was a manager in one of the biggest stores for over 10 Years, am also an SEO by night. I don't like to call myself a blogger; they are very analytical, do email marketing, and know all SEO stuff. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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