How to Install a Bathtub on a Concrete Floor

If you have a small bathtub, you may want to upgrade to a bigger one that you can soak in. An updated bathroom design may be achieved by installing a new bathtub.

Nevertheless, installing a bathtub on a concrete floor necessitates some additional steps.

It’s not that you’ll need a professional, but understanding how to install a bathtub on a concrete floor will make your job a little less stressful. Additionally, the installation method will be simple and won’t cause any damage to the floor or tub.

DIY bathtub installation takes extreme care and attention to detail. It is not a job for the faint of heart. It will be required to remove the old tub and reinstall the new one, ensuring that all of the tub’s working elements are properly connected.

How to Install a Bathtub on a Concrete Floor:

Tools you Will Need

Here is the complete list of essential tools you will need for installing the bathtub.

  • Sealing material
  • Soap and rag
  • Floor coating
  • Wood piece for installing the tub
  • Screws and Studs for installation

Step 1: Make Sure the Spray Area is Secure

To avoid getting water on the walls and floor, you should install a “spray area” around the tub. To put it another way, this includes all the space around the tub itself.

When working on a concrete or tile floor, you must ensure that the surface is watertight before you begin any work there. If you don’t, you could have to deal with a rotten floor.

Hardware or plumbing stores have a waterproof sealant. Use soap and a cloth to scrub the walls thoroughly before applying the sealant.

The sealant won’t stick to the surface if it’s covered with dirt or dust. It might come off easily or not work at all.

Step 2: Make the Floor Level

Concrete or tiled floors may be uneven even after a lot of effort is put into them. There is nothing anybody can do to prevent these human blunders.

This is a bad thing since the bathtub is more susceptible to breaking on an uneven surface.

Your floor may not need any particular attention if you’re fortunate. Concrete floors may be uneven, although this isn’t unusual. If you want to achieve the right balance while installing a bathtub, the floor underneath must be level.

Examine the condition of the flooring in the room. Is it possible that the floor isn’t level? The next step is to apply a waterproof sealer or caulk to the concrete slab.

If you’re having trouble getting an even surface, use your notched trowel as a guide and keep applying this stuff in layers until you achieve it.

Don’t go forward until the sealant has fully dried.

Step 3: Set Up the Bathtub

This may seem to be the simplest stage, but it really demands a great deal of time and attention. The bathtub will be installed exactly where it should be.

Measure the drain size and place the tub where there is already a drain to make things easy. Line the tub’s drain hole with the current spout’s pipework to the best of your ability.

It’s possible that you’d want to collaborate with someone. In order to avoid damaging the floor or drain, it’s necessary to be delicate with the tub while putting it down.

In order not to damage the drain, be patient and move the tub carefully during this time.

Step 4: Make Sure the Bathtub is Level

After that, you’ll be preoccupied with the leveling procedure. A level bathtub should have an equal location on the floor in all four corners.

A rubber mallet and a 2×4′′ are used in this project. Using a mallet, tap the wood against the tub until it reaches the desired location.

Make sure that the bottom of the tub is in the correct position against the sealant, and that the tub itself is level.

In order to level the tub, hit it with a mallet and a piece of wood. When it’s leveled, use the right amount of sealing compound to make sure it stays put.

Step 5: The Screwing Procedure

Screws for the installation of your bathtub model should have been included in the box you received it in.

You’ll use them to fasten the bathtub flange to the wall by drilling into the drywall.

To accomplish this, you’ll probably need to consult the handbook. One screw should be placed every six inches along the tub’s flange. Adjust as necessary.

Step 6: Inserting a Drain

You’ve now positioned the bathtub such that it’s parallel to the drainpipe already in place. The threading pipe must now be inserted into the male thread until it reaches the drain’s bottom.

To make things easier, you’ll be able to use the existing plumbing.

Step 7: Install all Remaining Components

The plumbing will need to be extended to other portions of the bathtub. This includes the plunger, linkage, and overflow rod.

Installing them appropriately with an overflow hole will allow the bathtub to properly drain any extra water that may accumulate. After that, use screws to tighten the apparatus.

Step 8: Threading the Spout

That’s all there is to it. Insert your spout pipe into the hole and secure it with pliers. The spout may already be fitted on certain models, so this step may not be required.

Step 9: Put the Tub Through its Paces

Make sure that the overflow drain and stopper are operating correctly before completing the concrete floor installation of your bathtub. In addition, make sure that the screws are correctly fastened.

Finally, you’ve completed the installation of the tub.

What Do You Put Under a Bathtub for Support?

A hefty bathtub or one that is expected to bear a significant amount of weight necessitates the use of a layer of mortar underneath it.

When the mortar is still warm, it’s simple to alter the tub’s level. When the mortar hardens, it acts as a fulcrum to keep the tub in place and hold its weight.

  • Level the flooring in the alcove where you wish to put the bathtub, then cut a drain hole.
  • Afterward, wait two hours for each application of primer to dry completely before moving on to the next one.
  • A pencil may be used to trace the tub’s contour on the flooring if desired.
  • Fill a 5-gallon bucket approximately three-quarters full with a thin-set mortar or floor leveling compound.
  • Place piles of 2 inch-high and 4 to 6 inch-wide mortar or leveling compound on the floor.
  • Set the tub on the piles as soon as they are still wet. ‘ Make sure the tub is level by adjusting it as necessary.

Installing a Platform for Bathtub

An enclosed platform bathtub is framed and finished with tile, wood, or any other material.

In addition to the construction and plumbing expertise and equipment needed to create the platform and install the unit, its water and drain lines, and its faucets, the job may require strengthening the existing floor framework.

  • Calculate the platform wall studs’ height based on the platform’s required height and the height of your tub.
  • Place studs on top and bottom plates to build platform walls by nailing studs together.
  • Nail the wall structure to the floor, then screw plywood over the framework to build the deck.
  • A jigsaw can be used to cut a hole in the deck for the tub. You can use the manufacturer’s template or write down the rough opening’s measurements before you start.
  • Putting in supply pipes should be as simple as measuring and marking where they should go, according to the manufacturer’s instructions.
  • When you’ve drilled the holes in the deck, rough in the water supply and drainage pipes.

How to Install a Tub in a Basement Without Breaking Concrete?

Adding a shower or a bathtub in many ways, building a tub or shower in your basement is similar to doing so in your bathroom as well.

In order to add plumbing, you may have to demolish the floor and dig.

As with any other room, you may build a shower if there are plumbing stubs accessible. Basement bathtub installation is not as difficult as it seems.

In the basement, adding a tub or shower entails many of the same problems as installing a toilet. Plumbing installation may require floor demolition and excavation.

A shower may be installed in the same way as any other room, as long as the plumbing stubs are accessible. The shower may be connected to an up flush toilet or sewage-ejector system.


Installing a bathtub on a concrete floor doesn’t have to be a complicated process. The most important thing is to make sure the floor is level and that the bathtub model is correctly positioned.

With the proper instruments and attention to detail, there should be no problems.

Installing the drain and piping should also be straightforward. To avoid having to re-thread any of the pipes, it’s ideal to align the tub with the existing plumbing.