How to Fill Void under Bathtub

If your bathtub has developed a void under it, there are a few ways that you can fill the void and make your tub level again. One way is to use hydraulic cement. This is a type of cement that is designed to set quickly underwater.

To use it, mix the cement according to the package directions and then apply it to the void with a trowel. Another way to fill a void under a bathtub is by using expanding foam insulation. This material comes in cans and can be sprayed into the void.

The foam will expand as it dries and will fill the entire space.

  • Remove all items from around the bathtub
  • This includes shampoo, soap, and any other items that may be on shelves or in drawers near the tub
  • Turn off the water to the tub
  • There will usually be a knob near the top of the tub that controls water flow
  • Use a plunger to try and remove any blockages in the drain
  • If this does not work, you may need to use a snake or other tool to clear the drain before proceeding
  • Once the drain is clear, apply silicone caulk around the perimeter of the void under the tub
  • Be sure to smooth it out as you go so that there are no gaps or air pockets in the sealant

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Spray Foam Vs Mortar under Bathtub

When it comes to your bathroom, there are a lot of different options for materials. Two popular choices for under the bathtub are spray foam and mortar. So, which is the better option?

Mortar is a traditional choice for under the bathtub. It’s easy to work with and can be found at most hardware stores. Mortar is also a very durable material, so it can withstand a lot of wear and tear.

However, mortar can be difficult to apply evenly and can crack over time. Spray foam is a newer option that has become increasingly popular in recent years. Spray foam is easy to apply and dries quickly.

It’s also very versatile- you can use it on virtually any surface. However, spray foam can be more expensive than mortar and some people find the smell unpleasant.

Expanding Foam under Bathtub

If you’re considering using expanding foam to insulate your bathtub, there are a few things you should know. Expanding foam is a type of insulation that is sprayed into place. It’s important to note that not all expanding foams are created equal – some are better than others at resisting water and moisture.

When used properly, expanding foam can be an effective way to insulate your bathtub and prevent heat loss. However, if the foam is not applied correctly or if it gets wet, it can cause problems. Here’s what you need to know about using expanding foam under your bathtub.

The first thing to consider is the type of expanding foam you use. There are two main types of expanding foam: closed-cell and open-cell. Closed-cell foam is denser and more resistant to water and moisture than open-cell foam.

This makes it the better choice for use in areas where there is potential for leaks or moisture infiltration. Open-cell foam is less dense and more porous than closed-cell foam. It’s also less expensive, making it a good choice for projects on a budget.

Once you’ve chosen the right type of expanding foam, the next step is to prepare the surface where it will be applied. The surface should be clean, dry, and free of any debris or contaminants. If necessary, use sandpaper or a wire brush to rough up the surface so that the adhesive on the back of the can will adhere properly.

Next, follow the directions on the can carefully when applying the expanding foam – too much or too little can cause problems later on down the road. Be sure to wear gloves and protective clothing when working with this product as it can be messy! Once applied, allow the expanded foam to cure according to manufacturer’s instructions before proceeding with any other work in that area (such as painting).

Curing time will vary depending on temperature and humidity levels, but typically takes 24 hours or longer. Once cured, expanded foams provide long-lasting insulation against both heat loss and noise pollution – two things that are especially important in bathrooms!

No Concrete under Bathtub

If you’re like most people, you probably assume that the concrete slab beneath your bathtub is there to provide a sturdy foundation. However, that’s not actually the case. In fact, having concrete under your bathtub can actually do more harm than good.

Here’s why: Concrete is a porous material, which means it can absorb water. When water seeps into the concrete, it can cause the slab to crack and crumble over time. Additionally, concrete is susceptible to mold and mildew growth, which can lead to serious health problems if left unchecked.

So what’s the best solution? Well, you might be surprised to learn that there’s actually no need for concrete under a bathtub at all! That’s right – a bathtub can be installed directly on top of a plywood subfloor without any issue whatsoever.

Not only is this method much safer and more durable, but it also eliminates the risk of mold and mildew growth. So if you’re looking to protect your investment (and your health), ditching the concrete is definitely the way to go.

Foam Board under Bathtub

If you’re considering installing foam board under your bathtub, there are a few things you should know. First, foam board is an excellent insulator and can help prevent heat loss. Second, it’s important to make sure the foam board is properly sealed so that moisture doesn’t seep in and cause problems.

Third, foam board can be cut to fit any size tub, so you’ll need to measure your tub before purchasing the material. Finally, installation is relatively easy and only requires a few tools. Foam board is a great way to insulate your bathtub and prevent heat loss.

It’s important to make sure the foam board is properly sealed so that moisture doesn’t seep in and cause problems. Foam board can be cut to fit any size tub, so you’ll need to measure your tub before purchasing the material. Installation is relatively easy and only requires a few tools.

Under Bathtub Support

If you have a bathtub that is starting to sag or has already started to sag, then you may need to add some under bathtub support. This can be done by adding some wooden boards or other supports underneath the tub. You will want to make sure that the supports are evenly distributed and that they are securely fastened so that your tub does not continue to sag.

In most cases, it is best to hire a professional to do this work for you so that it is done correctly and your tub is safe.

How to Fill Void under Bathtub


What Do You Put under a Bathtub for Support?

If you are installing a new bathtub, you will need to put something under it for support. The most common material used for this is wood. You can use either plywood or 2x4s.

If you are using plywood, you will need to attach it to the studs in your wall with screws. If you are using 2x4s, you will need to nail them together and then screw them into the studs in your wall. Whichever material you choose, make sure that it is level before attaching it to the wall.

How Do You Fill a Void under a Fiberglass Tub?

If your home has a fiberglass tub, you may eventually need to patch or repair it. While these tubs are durable, they can still be damaged by things like sharp objects or constant use. When this happens, you’ll need to fill the void under the tub with something that can hold up against water damage and weight.

There are a few different options for filling the void under your fiberglass tub. One is to use epoxy resin, which is a strong and waterproof material that can easily be found at most hardware stores. Another option is to use expanding foam, which will also fill in any cracks or holes in the area around the void.

Whichever method you choose, make sure to follow the instructions carefully and allow plenty of time for the material to dry before using the tub again. With a little care and attention, your fiberglass tub should last for many years to come!

What is Underneath a Bathtub?

Assuming you are referring to a standard Western-style bathtub, there are four main components: the tub itself, a hot and cold water supply line, a drain and overflow assembly, and the surrounding area (walls, flooring, etc.). The tub is typically made of enameled cast iron or steel. The supply lines bring fresh water into the tub.

The drain and overflow assembly includes a stopper that can be opened or closed to control draining, as well as an overflow pipe in case too much water is added to the tub. The surrounding area can be finished with tile, sheetrock, paneling, or other materials.

Do You Have to Use Mortar under a Bathtub?

No, you don’t have to use mortar under a bathtub. However, doing so can provide extra support for the tub and help prevent it from shifting or moving over time. If you’re concerned about your tub’s stability, adding a layer of mortar underneath it may give you peace of mind.

How To Sturdy Up a Fiberglass Tub Shower Using Spray Foam


void beneath a bathtub is both unsightly and dangerous, as it can be a tripping hazard. Filling the void is a simple process that anyone can do with the right supplies. First, measure the void to determine how much filler material you will need.

Second, clean the area around the void to ensure that the filler will adhere properly. Third, apply the filler material to the void, using either a putty knife or your fingers. Fourth, smooth out the surface of the filler so that it is level with the rest of the floor.

Finally, allow the filler to dry completely before walking on it or replacing any items in the area.