Quck answer
To install a drop-in bathtub with platform, follow these steps:
1. Measure and mark the area where the bathtub will be placed, ensuring it fits properly.
2. Build a platform using plywood or a pre-made platform kit, making sure it is level and sturdy.
3. Install the drain and overflow assembly according to the manufacturer’s instructions.
4. Set the bathtub onto the platform, making sure it is centered and level.
5. Connect the drain and overflow pipes to the plumbing, using adhesive or plumber’s tape for a secure fit.
6. Secure the bathtub to the platform using screws or brackets, following the manufacturer’s recommendations.
7. Test the bathtub for any leaks or issues before using it.
By following these steps, you can successfully install a drop-in bathtub with a platform.
Similar to a drop-in sink, a drop-in bathtub has a rim that rests on an enclosure. The most crucial part of installing a drop-in bathtub is building the tub surround. The surround is typically a rectangular box built into an alcove, jutting out from a wall or sitting in the middle of the floor. Although many surrounds aren’t rectangular, building one is easier than constructing a round or oval one.
Drop-in bathtubs are commonly made of lightweight acrylic or fiberglass, but you can also find heavier ones made from cast iron, porcelain, stone, and solid surface materials. Heavy materials retain heat longer, providing a better soaking experience. A lightweight acrylic tub can also become heavy when filled with water, so the rim isn’t designed to support the tub all by itself. Some manufacturers suggest leaving a 1/16-inch (2-mm) space between the rim and the tub decking, allowing the tub to be entirely supported from underneath by a mortar bed resting on a solid subfloor, Kohler being one of them.
An undermount bathtub is a variation of a drop-in tub that some people prefer. The lack of an exposed rim makes it easier to keep the tub deck free of water, reducing the chances of mold growth and preventing slipping. The only significant difference between them is that you may have to construct the surround around an undermount tub, whereas you can place a drop-in tub into the surround after framing it.
A Detailed Guide on Installing a Drop-In Bathtub
Similar to a freestanding tub, a drop-in tub can be located anywhere plumbing is available. The first step in installing a drop-in bathtub is choosing the best location for it. As it’s primarily a soaking tub, you may want to place it next to a window to enjoy the view. You can even set it in a living room with a suitable waterproof floor. It’s best to build the surround next to a wall as it simplifies plumbing installation, allowing you to run the water pipes behind the wall as you would for a conventional alcove bathtub. In fact, it’s common to locate a drop-in tub in an alcove.
The installation process starts with the construction of the surround, which must be sturdy enough to support the tub and at the right height to allow the tub to rest on the floor with the rim resting on the surround decking (with any gap specified by the manufacturer). Most people cover the surround with wood or tile, and it’s best to install the covering after setting the tub to make it easier to finalize the plumbing connections. However, there is one exception. You should cover the decking before installing the tub to allow the rim to rest on the finished surface. This makes installing the decking easier and avoids leak-prone gaps around the rim that are likely if you cover the decking after tub placement.
After constructing the frame of the tub and installing the drain assembly, it is typical to create a 1-2 inch mortar bed at the bottom of the surrounding area. Once the mortar sets, the tub can be dropped in and the drain can be connected. It is recommended to build an access panel for plumbing repairs to avoid having to demolish part of the surround. If you’re installing a whirlpool tub, an access panel is required by code to reach the electrical components.
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krooogle/iStock/GettyImages
Preparation for Installing a Drop-In Bathtub
A level and sturdy subfloor is necessary for a drop-in tub, which can weigh up to 600 pounds when filled with water and occupied by someone weighing 200 pounds. If the subfloor feels unstable, consult a contractor for any necessary repairs. It is important to avoid having a rotten or sagging floor joist under the new bathtub. If the floor is solid but not level, you can fix it by screwing a sheet of 3/4-inch plywood to the floor with shims underneath it.
If the tub surround is next to a wall, it is possible to install the water pipes, faucet valve, and tub spout in the wall before building the surround, especially if you’re planning to tile both the wall and the surround. However, it is not always necessary to install the faucet before setting the tub. For a freestanding tub, the faucet is often mounted on the floor beside the tub. It is advisable to install it after setting the tub to avoid having pipes in the way when lifting the tub into the enclosure.
The drain line for the tub should come in under the floor. Although the drain rough-in can be done after setting the tub, a cutout in the subfloor is necessary for the pipe that connects the tub drain and overflow drain. The cutout should extend from the tub drain to the front edge of the tub, a distance of about 12 inches and be approximately 3 inches wide to allow the horizontal part of the tub drain assembly to hang below the floor.
Installation of a Drop-In Bathtub
Step 1: Measure the Height of the Rim
To install the tub, unpack it and set it upright on a pair of 2x4s to raise it off the floor. Ensure that the drain opening in the bottom of the tub and the overflow drain opening are accessible. Place the tub as close to the installation location as possible to avoid having to carry it far.
Measure the distance from the underside of the tub rim to the surface of one of the 2x4s. Add the manufacturer’s recommended gap allowance and then add an inch for the mortar bed to get the height you need to build the enclosure. If you’re going to finish the enclosure deck before setting the tub, don’t forget to subtract the thickness of the finish material.
Step 2: Constructing the Enclosure Frame
To construct the frame for the tub enclosure, use either 2×4 or 2×6 lumber. Using 2×6 lumber strengthens the frame while also providing a wider deck for holding toiletries and drinks. The frame must be wide enough to allow the tub to drop, while still providing at least 1 inch of overlap for the rim on the deck. Check the manufacturer’s specifications for the exact inside dimensions of the enclosure.
For drop-in alcove-style tubs, the enclosure frame should include ledger boards on all three sides to support the rim. The top of each ledger should be at the same height as the deck on the front wall, and all ledgers should be dead level.
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Andersen Ross/DigitalVision/GettyImages
Step 3: Cutting Out the Drain Opening
Measure the bathtub drain’s location with respect to the sides and end of the tub and mark the subfloor the same distance from the sides and front end of the enclosure. Use a reciprocating saw to cut an elliptical hole in the subfloor that extends from the front wall of the enclosure to a distance of about 2 inches behind the mark and that is about 3 inches wide.
Step 4: Installing the Bathtub Drain Assembly
For a DIY home improvement project, choose a PVC bathtub drain assembly kit that includes elbow connections for the drain and overflow holes, a sanitary tee, pipes to connect these components, a drain flange that gets screwed onto the drain elbow from inside the tub, and an overflow plate with screws to hold the overflow elbow. Measure the distance from the drain opening to the front of the tub or look it up in the manufacturer’s specs and cut a length of pipe to that length plus 2 inches of overlap (1 inch on either end). Dry-fit the drain and screw on the flange loosely, then dry-fit the tee and measure the distance from the overflow opening to the tee inlet. Cut another length of pipe to span the distance with a 2-inch overlap, then dry-fit the entire assembly to make sure it fits before gluing everything together.
Secure the drain fitting to the tub by packing the flange with plumbers’ putty, inserting it through the drain opening and screwing it loosely into the drain elbow. Install the overflow plate and tighten the screws with a screwdriver. Then, tighten the drain flange with a drain tool.
Step 5: Preparing the Mortar Bed
Mix a bag of mortar with water to a dry, crumbly consistency. Shovel the mortar onto the subfloor and spread it evenly with a trowel to the depth that you predetermined when you built the enclosure, keeping in mind that the tub will compress some of the mortar and push it out of the way as it settles. Some builders recommend embedding steel netting in the mortar to prevent it from cracking, and it’s a good idea to put plastic sheeting under the mortar to keep moisture out of the subfloor.
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Siraphol/iStock/GettyImages
Step 6: Place the Bathtub on the Mortar Bed
Put 1/16-inch spacers on the tub deck to be removed when the tub rim is resting on them. Then, lift the bathtub over the enclosure and lower it gently onto the mortar bed. Depending on the weight of the tub, this requires two or three people. Check the level of each of the tub rims, move the tub as needed, and let it settle onto the spacers.
When the tub is level and at the correct height, wait for the mortar to harden. Next, attach the rim to the enclosure using the manufacturer’s recommended hardware or other means and remove the spacers. For an alcove installation, use screws or nails to secure the flange to the wall studs.
Step 7: Seal the Tub Rim with Silicone Caulk
Put a line of silicone caulk along all exposed edges of the rim to keep water from seeping under the rim and behind the walls of the enclosure. If it’s an alcove tub, cover the nailing flange with wall covering and caulk the gap between the bottom of the wall covering and the tub rim (the gap should be less than 1/4 inch).
Step 8: Complete the Tub Surround
Use drywall or cement board to cover the tub surround frame. Then, use wood panels, tiles, or another material to finish the final covering.
Step 9: Connect the Plumbing
Attach the tub drain assembly to a P-trap and connect the trap to the drain line. If the drain plumbing won’t be accessible after you cover the ceiling in the room below, use an ABS glue-together drain instead of one with compression nuts that might leak.
If you haven’t already, install the water supply lines, tub faucet valve, tub spout, and showerhead. Leave the drain pipes uncovered until you fill the tub and check for leaks.
FAQ
1. What materials do I need to install a drop-in bathtub with a platform?
You will need the following materials to install a drop-in bathtub with a platform: the drop-in bathtub, a platform or support structure, a level, a drill, screws or nails, a tape measure, a pencil, a saw, a silicone adhesive, and plumbing supplies.
2. How do I prepare the bathroom floor for the platform?
To prepare the bathroom floor for the platform, start by measuring the dimensions of the bathtub and platform. Use a tape measure to mark the outline of the platform on the floor. Next, remove any existing flooring within the marked area. Ensure that the floor is level and make any necessary adjustments. Finally, secure the platform to the floor using screws or nails.
3. What is the process for installing the drop-in bathtub on the platform?
To install the drop-in bathtub on the platform, start by placing the bathtub in the desired location on the platform. Use a level to ensure that the bathtub is perfectly horizontal. Once the bathtub is level, mark the outline of the bathtub on the platform. Remove the bathtub and apply a generous amount of silicone adhesive within the marked outline. Carefully place the bathtub back onto the platform and press it firmly into the adhesive. Allow the adhesive to dry completely before using the bathtub.
4. How do I connect the plumbing to the drop-in bathtub?
To connect the plumbing to the drop-in bathtub, start by installing the necessary plumbing fixtures, such as the drain and overflow assembly. Follow the manufacturer’s instructions for the specific fixtures you are using. Once the fixtures are installed, connect the plumbing pipes to the fixtures using the appropriate fittings. Ensure that all connections are tight and secure. Test the plumbing by filling the bathtub with water and checking for any leaks. Make any necessary adjustments to fix any leaks.
5. Are there any additional considerations for installing a drop-in bathtub with a platform?
Yes, there are a few additional considerations for installing a drop-in bathtub with a platform. Firstly, ensure that the platform is sturdy and can support the weight of the bathtub and water. Additionally, make sure that the platform is level to prevent any issues with the bathtub’s stability. Finally, consider the overall design and aesthetics of the bathroom when choosing the style and color of the drop-in bathtub and platform to ensure they complement the existing decor.