Make Bathroom Renovations EasierLearn More
Make Bathroom Renovations Easier


Tub Shower Combo Remodeling Quick Tips

Details Matter

As Seen On
by Jeff Patterson in How to Build a Shower
Tub Shower Combo Remodeling

If you want to remodel an outdated tub & shower you’re in the right place.

Over the last several years we’ve been making tutorials on this exact type of project.

Even if you’re a complete DIY beginner we believe you can do a tub shower combo remodel.

And today you’ll get a lot of tips you won’t see in books or anywhere else online.

Plus, we have a few surprises for you. Let’s dive in.

Step 1: Demo the Old Tub Shower Combo

Many bathrooms have those old one piece fiberglass surrounds. The only way to get them out is to cut the fiberglass into three pieces.

Before you do anything, turn the water and electricity off to the bathroom.

Remove all the old plumbing fixtures, like the mixing valves plumbing.

Remove tub plumbing

And the shower head and tub spout.

Tub spout

Then use a reciprocating saw to cut the fiberglass at each corner in the tub surround.

Cutting tub shower combo

This makes it easy to remove the plumbing wall, back wall and main wall.

Removing Tub Surround

You’ll have to disconnect all the pipes from the tub and then you can remove it as well.

Check out “How to remove a fiberglass bathtub and surround” for more detailed steps


Step 2: Check the Subfloor

Every tub shower combo remodel will be nothing short of a pain if the subfloor isn’t level.

Place a 4 foot level on the subfloor.

Check floor

If the subfloor is level you can move on to the next step.

If you the subfloor isn’t level and is off by more than a 1/2 inch you’ll want to inspect the joists.

Fixing joists is not for the faint of heart. But you can sister new 2×8 or 2x10s to old joists to improve the structural integrity of your home.

Subfloor repair

Sometimes plumbers will cut through joists to make room for pipes. And the notches they make compromise the joist to the point where it starts to sag. This in turn can lead to the sublfoor sagging.

If you’re not comfortable fixing the joists call a professional.

Water damaged sublfoors can be replaced with plywood or OSB.

Subfloor installation

DITRA and other isolation membranes have specific requirements for subfloors.


Just be sure to read the handbook for DITRA in order to use the correct subfloor thickness.

We recommend using DITRA or DITRA-HEAT under tile.

Primarily because DITRA will prevent tiles from cracking and you can completely waterproof the bathroom floor while you’re redoing the tub shower combo.

Tile floor

Sometimes the only part of the subfloor that isn’t level is where the tub needs to go. You can use self-leveler to help remedy this situation.

Self Leveler


Step 3: Setting the Tub and Tub Plumbing

Setting a tub is WAY easier when the subfloor is level.

Rest the tub in the alcove.

Setting a Tub

And place a 4 foot level on all four sides.

Then secure the tub to studs using galvanized screws.

Steel or cast iron tubs are secured to studs using galvanized washers and screws. It’s a bit difficult to drill through steel or cast iron!!

Secure steel tub to studs

Sometimes the tub needs a 2×4 stringer for support.

Stringer for tub

Read the tub directions to be sure you need a stringer because sometimes they’re not required.

One of the biggest tips we have for tub drains is to use 100% silicone to seal them to the tub.

Silicone for drain

Also, know the height requirements for the tub spout, mixing valve and shower arm.

Plumbing requirements

In general, at least here in Pittsburgh, the tub spout is 3-4 inches off the tub deck.

Spout height

The mixing valve is 9-18 inches off the tub deck.

Mixing valve height

And the shower arm is 80 inches off the subfloor.

Shower arm height

And if you can use a mix if PEX and copper with the mixing valve that will save you some time.

PEX and Copper

Check out “Shower Valve Replacement In 30 Minutes or Less” for more detailed instructions

Step 4: Frame the Shower Niche and Waterproof

Before you frame a shower niche it’s best to know the size of the tile, grout joint spacing and tile layout.

That way the tile won’t look wonky when set on the substrate.

Frame a shower niche using standard 2×4 framing.

Shower niche framing

Here’s a picture of the tile that went around our niche.

Shower niche tile

It gives you a good idea of the importance of planning.

Waterproofing options include KERDI-BOARD






And cement board

Cement board

If you use cement board waterproof it with something like RedGard



Step 5: Set Tile on Main Shower Wall

Set the first row of tile on 1/16″ or 1/8″ plastic spacers.

First row of tile

This provides a gap between the tile and the tub.

That gap can be filled with silicone.

Silicone tub

The reason for the gap is to allow expansion and contraction between the tub and the tile.

And if you’re using large format tiles, e.g. 12×24 inch tiles, it might not be a bad idea to use a tile leveling system. This helps tune the tiles and prevent lippage.

In addition, plan the tile layout so that you have a good piece of tile at the ceiling.

Tile to ceiling

Anything less than 2 inches will look pretty weird.


Step 6: Tile Remaining Walls

Plumbing walls always present a challenge because of holes for tub spouts and mixing valves.

Cut holes for mixing valves using a carbide tipped hole saw.

Carbide hole saw

Holes for tile

Holes for mixing valves require a different set of tools.

Mixing Valve Holes

Angle grinders equipped with diamond blades are great for cutting large, e.g. 3 to 4 inch, holes.


Angle Grinder

Take your time when cutting holes in tile and wear all the safety gear to protect your eyes, skin and ears.

Setting the tile on the last wall is similar to the other two. Use spacers at the tub and know your layout in advance.

Last wall

If you want to save money you can use Schluter metal profiles instead of bullnose tiles.

Schluter profile

One 8 foot section of Schluter profile costs $20 to $30 and comes in a variety of colors and finishes.

For more tips and to see the types of grout we like watch our video

Tub Shower Combo Remodeling Quick Tips


What’s Next

We hope you liked today’s tips on tub shower combo remodeling.

If you’re doing a bathroom remodel and want to simplify the process enroll into the Bathroom Repair Tutor Video Library

We show how to build showers (Schluter, Wedi, Curbless, etc.), install tile, upgrade basement bathrooms, and more.

The extra guidance is invaluable

Enroll Today



Jeff Patterson





  1. Douglas Scott says:

    HEY you guys I use your tutorials right often I have experience but after chemo and age am forgetful and confused you really HELP me !,doing a tub shower combo I would be very thankful for any tips

    1. Glad to help Douglas, let us know if you have any questions. We’d be happy to help.

  2. Rick Woodard says:

    I see that you use both a plastic waterproof barrier and red guard. Is there a reason you use both?

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Translate »