Super Shower ONE: demo and framing

This post describes the demo and prep steps for transforming a terrible bathroom space into a groovy vintage-modern spa shower space. It took a lot of work, and so the description is pretty long. If you’d like to skip ahead to the actual tile install and finish steps, then just click this “Super Shower TWO: making the actual shower!” link.

But, if you’re interested to read about all the gloriously gory demo and prep work that’s often required for a literal ground-up full renovation project, then read on!

The Before — retro without the charm

Sometimes a classic 70s -era bathroom design can make even avocado -colored tile look good. This was not one of those designs.

This vintage house had a master bath layout designed as a literal his/hers split, with no access in between. Metaphors aside, having a small “garden style” inset tub on one side and a low-ceiling cramped and damp shower stall on the other with no access in between was pretty terrible.

The client’s reno goals were to open up the space visually, get some kind of walk-through access between the his/hers bathroom split, create a spa-quality shower, and do all this with minimal structural changes.

Here are some “before” pics to illustrate the challenge:

The pictures are kinda hard to make full sense of since the original side-by-side bathroom layouts were so unconventional. So, here’s a rough sketch of the original layout along with the final conceptual design that the clients settled on:

Since the house has a second full bathroom with a tub, getting rid of the master bath tub was no problem for resale. And, since the master bath shower needed to be demolished anyway (traditionally constructed showers have a ~30 year lifetime), eliminating the tub/shower dividing wall was an easy design decision. In practice, though, “easy” can be a relative term.

Knocking a few exploratory holes in the walls revealed that all of the shower and tub surround wall tile had been installed with a very old-school wire and concrete lath substrate. It took a lot of sledgehammer work to demo:

Full demo revealed that the shower waterproofing (a vinyl liner) had been leaking moisture for awhile, which is typical for a ~40 year old original shower install. Even though the shower hadn’t been used in months, there was still some moisture and a mold layer lurking underneath the shower base:

Again though, some mold and minor water damage is about the best-case scenario for an old shower constructed with 1970s -era materials and methods. Opening everything up to dry and replacing some wall framing fixed those issues.

The only unexpected difficulty was some pretty inconvenient wiring placement. The main electrical panel and wire runs for the entire house were located in one of the shower walls (way to go, original builder). And, all the main wire runs were laid over top of the original shower drop ceiling with absolutely zero slack.

And remember, the whole shower/tub area was built on a “dais” of concrete and masonry that would’ve been very difficult (and therefore very expensive) to completely demolish back down to the original concrete slab foundation.

So, how to maximize shower space when the lowered ceiling can’t be raised and the raised floor can’t be lowered? Be creative and slope the ceiling to make the shower space as tall as possible along the wall that counts the most:

These pics are a jump ahead in project time though. Even getting to the framing and supply plumbing rough-in stage took a lot of work.


For example, there was still the little task of demolishing and hauling away two very large built-in vanity cabinets and countertops, several tile walls with concrete and wire substrate, a cast-iron tub, and a lot of masonry. It took four pickup loads for toting everything to the landfill:

STEP TWO: Framing and Electrical

Framing out the new walk-through shower footprint required extending a wall and re-framing two entryways. And, adding a new ceiling:

The reconfigured shower would get a lot of natural light from the 2×6 -ft window that would now illuminate the entire space. But it’d still be pretty dark at night if lit by only a single original overhead bulb fixture. So, some straightforward rewiring added a pair of IC -rated moisture -proof can lights with two-way switches for convenience:


STEP THREE: Detour for Plumbing!

The plan was to plumb the new walk-through shower with two showerheads and valves. Splitting one hot and one cold water line between two showerheads can result in low water pressure at the showerhead (like forking a river in two — each branch gets just half the water volume). So, it’s always best to plumb a dual-head shower setup to two separate water line runs.

Since the original bathroom(s) had the tub and shower on separate hot/cold lines, simply extending the original copper supply plumbing was easy using modern PEX piping:


The drain plumbing, however, required a bit more work.

STEP FOUR: Concrete, and then MORE Concrete

The original shower drain was too elevated to use for the new shower configuration. And, since it was encased in three feet of concrete, the original shower drain was also just too much of a hassle to jackhammer out and replace.

Fortunately, the original tub drain was in a great location for the new shower configuration — almost precisely centered between where the new showerheads would be. Also, since it was a tub drain, the drain riser pipe wasn’t completely encased in concrete:


However, old tub drains (and most pre- 1990s shower drains) have a 1-1/2 inch inside diameter. Modern plumbing codes require a 2-in drain for showers. While this code requirement is arguably overkill for a standard single-head shower, this shower design would use two showerheads plumbed to two separate water supply runs. So, at full flow, the new shower would pump out 5-gal of water per minute (double the 2.5-gal per minute of a standard shower).

Also, testing the drain revealed that it was partially blocked to begin with. There was no way this original tub drain pipe would work for even a standard shower install without some major work. Luckily, jackhammers are easy to rent!


Getting access to the main drain line below the slab required widening the foundation slab hole and a bit of digging. This is what it looked like after a few hours of dusty messy work:


You can now see the original cast iron p-trap and underslab drain pipe. With everything exposed and plenty of working room, it was an easy job for the plumber to cut the cast iron pipe cleanly and attach a new PVC p-trap and riser using a stainless-steel jacketed no-hub coupling:

With a perfectly centered 2-in diameter PVC drain riser now in place, the foundation slab hole was ready for backfill and repair. And, with a 48-hr cure, the whole sunken tub concrete cavity was ready to be filled with more backfill and concrete to make a nice level foundation for the new shower floor:


STEP FIVE: Buttoning up the walls

While the drain plumbing work was progressing, I was also completing the framing and backerboard install work for the walls and ceiling. Since this was a one-story home, the shower ceiling needed a good vapor barrier to prevent moisture from condensing on the backside of the drywall. And, since the shower was on an external wall, this needed a good 6mil plastic vapor barrier too.

Realize that this vapor barrier behind the backerboard is not a substitute for proper shower wall and ceiling waterproofing! It simply prevents outside moisture (moist cold air in the attic or exterior wall stud bays) from condensing due to the temperature differential created by a hot shower room.

With the ceiling and exterior wall all nicely insulated and protected from condensation, it was now time to button everything up with drywall and concrete backerboard:

And this then finally got the project to the point where a normal tile contractor would start — carpentry done, plumbing in place, ceiling finished, and wall backerboard all installed. Now all that was left was to actually make a new shower from the literal ground up!

To be continued in “Super Shower TWO: making the actual shower!