3 Essential Bathtub Mortar Bed Alternatives: Navigating Your Options

For the longest time, mortar has been the go-to material for creating the ideal foundation for a bathtub. We love it because it offers a stable and strong bed for bathtubs.

It also conforms to the shape of a tub while preventing pressure points that may damage the tub in the future.

However, of late, both DIY and professional installers have been considering other alternative installation methods. And today, I will be exploring some of the best bathtub mortar bed alternatives.

Bathtub installation

Top 3 Bathtub Mortar Bed Alternatives

1. Foam

Foam is a popular alternative to mortar beds in bathtubs. You can find information about it from remodeling companies or online forums.

You’ll also notice that a lot of people are switching to foam for their bathtub installations. Unlike mortar, foam is much lighter, and it can easily fit under the bathtub without requiring many modifications.

Advantages of Foam: Lightweight and DIY-Friendly

Foam is much easier to install than mortar. That makes it perfect for DIY enthusiasts.

Foam dries within 8 to 24 hours. This can significantly speed up the installation process.

Unlike mortar, foam has better insulation. Therefore, it can help preserve the temperature of the water in the bathtub.

Foam is also more adjustable than mortar. As a result, it can accommodate varying floor levels and tub designs.

If you’re going to use foam to install a bathtub, you won’t need professional help.

Considerations for Foam: Weighing Durability and Weight Support

Foam cannot withstand the weight of heavy bathtubs.

Also, foam is not as durable as mortar. Eventually, it will shrink.

Long-term exposure to moisture can degrade foam.

Some bathtub companies will not honor their warranty if you use foam as a bed.

2. Light Concrete Mixes

The second-best thing you can use instead of mortar under your bathtub is a light concrete mix.

This is a very rare option, but after conducting thorough research, I can confirm that a light concrete mix is strong enough to hold your bathtub and can serve you for many decades.

Benefits of Light Concrete: Strength Meets Ease of Installation

Just like a mortar bed, concrete can support the weight of a bathtub.

Because this mix is lighter, it’s easier to install. That makes it a perfect alternative for DIY folk.

Once it dries, lightweight concrete is moisture-resistant. which gives it an added advantage over these two alternatives.

Because it is light, such a mixture can be adjusted to blend with the design of a bathtub.

Factors to Consider with Light Concrete: Cost and Building Code Compatibility

The biggest drawback of using light concrete as a bathtub mortar bed alternative is the cost.

These mixes need to be prepared carefully. Any mistake can lead to serious issues later on.

Some local building codes will not support the idea of using light concrete mix under a bathtub.

3. Wooden Shims

The last alternative is wooden shims. But before you get all excited about supporting your bathtub with wooden shims, many factors are at risk. Let’s start with the benefits of using wooden shims as a bathtub mortar bed alternative.

Upsides of Wooden Shims: Affordability and Adjustment Ease

Shims facilitate better adjustments, especially when leveling your bathtub.

They can also come in handy if your subfloor is damaged.

They are super affordable.

Shims are much easier to work with compared to mortar.

Challenges with Wooden Shims: Structural Support and Moisture Sensitivity

The biggest drawback to using wooden shims is that they do not provide sufficient support. So, if you have a heavy bathtub, you’re in big trouble.

Wooden shims are sensitive to moisture. That means, eventually, they may rot.

Movements within the bathtub can cause shims to shift from their initial position, and that’s very risky.

Not all building codes will accept the use of shims under bathtubs.

Bathtub Installation

Plaster of Paris: A Viable Option?

Plaster of Paris may seem to have a lot of similarities with mortar. But it is not a suitable alternative. You should never use Plaster of Paris in a tub’s surroundings.

I have come across several posts recommending Plaster of Paris as a bathtub mortar bed alternative. But I would strongly advise you not to use it because of the following reasons:

Plaster of Paris will soak when exposed to moisture. This is bound to happen, considering it will be used in a bathtub.

Plaster of Paris is not as strong as mortar. So, it won’t be able to hold the weight of the tub.

This material is also vulnerable to cracks, especially when exposed to movements and high temperatures.

Adhesive for Bathtubs: A Modern Approach?

I would also not advise you to use construction adhesive as a mortar alternative in your bathtub. Yes, it creates a strong bond, but construction adhesive does not offer the structural support needed to hold a bathtub.

Not to mention, you’re going to have a difficult time adjusting the construction adhesive to fit the shape of your bathtub.

Bathtub Installation

Why Go for Mortar Bed Alternatives?

There are a couple of reasons why people are deviating from using mortar beds during the installation of bathtubs. These reasons include;

• Building a Bathtub Mortar Bed is labor-intensive

We’re living in an era where people prefer products that are easy to install. Unfortunately, mortar isn’t one of them.

Building a mortar bed is a laborious task, and it can be pretty challenging for most DIY enthusiasts. This is one of the main reasons most people are opting for bathtub mortar bed alternatives.

• Mortar Takes a long time to Dry

Mortar typically dries within 24 to 48 hours. It can take much longer if the conditions are humid and cold. If you want to use the bathtub immediately after it has been installed, then you have no option but to explore some of the alternatives below.

• Mortar Will Crack If Installed Incorrectly

The other tricky part about dealing with mortar beds for your bathtub is that they will crack if installed incorrectly. This is an issue that can be avoided by choosing another option that is more resistant to cracking.

• Technological Advancements

Mortar beds are the traditional method of installing bathtubs. Today, we have more technologically advanced systems that can support bathtubs. These alternatives are more durable and offer better performance than mortar.

Selecting the Ideal Mortar Alternative for Your Bathtub

The ugly truth is that these bathtub mortar bed alternatives have pros and cons. It’s up to you to compare the benefits and drawbacks that come with each so that you can make an informed choice.

To help you do that, I am going to leave you with the key factors you need to consider when evaluating these bathtub mortar bed alternatives:

• The recommendation by the bathtub manufacturer: If a manufacturer recommends only mortar, please don’t use foam or wooden chips. Doing so will void the warranty, and that’s the last thing that you should want.

• Evaluate the load-bearing capacity of the alternative material: Before using the alternatives listed above, make sure that they can accommodate the weight of the bathtub. Otherwise, you’ll be creating a recipe for failure.

• Choose a bathtub mortar bed alternative that can resist moisture: That’s the reason why I eliminated Plaster of Paris from this list. Considering that the bathtub is constantly exposed to moisture, you need a material that is resistant to water damage.

• Ease of installation: Because mortar is challenging to work with, the ideal alternative must be easy to install.

• Durability: This doesn’t need much explanation. You don’t want an alternative that will disintegrate in a month or two.

• Seek professional help: Finally, I’d advise you to seek professional help if you are still unsure about bathtub mortar bed alternatives.

Sometimes navigating through bathtub installations without experience or knowledge can be challenging. It can pay off to work with a skilled contractor.

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