Bathroom remodel, 2 of 3: "Structure and Stuffing"

In the prologue to this series of posts, I gave an overview of how this bathroom remodel project came about.

In Part 1, "Damage and Demolition", I showed you the damaged shower wall and how I cleared it all away.

This post, "Structure and Stuffing" (which the astute reader will notice is similarly alliterative) will be about the rebuilding and upgrading of the structural materials. These changes will give mechanical support to the tiling, as well as improve the overall performance of the walls.

Hypothetical reader of this blog post: Hang on a second, Tony. The "overall performance of the walls"? What kind of nonsense is that? Walls just stand there, right? Are you expecting them to do something else?

Tony Noland: Ugh, are you back? The explanation-through-dialog gimmick was marginally useful in Part 1, but do we have to go through the same routine here in Part 2?


Hrotbp: Yes, we do. All of your explanations were so fascinating in Part 1, I came back to see how it turns out. Now, show me some pictures before I get bored again.

TN: (grumbles about overused literary devices) Fine, take a look at these photos. As always, you can enlarge the photos by clicking on them.

Before the rebuild...

... after the rebuild

The photo on the left is a zoom in of the left wall, before I rebuilt it. The photo on the right is the same wall, after I rebuilt the structural members of the stud wall.

Hrotbp: I don't get it.

TN: What? What do you mean? Isn't it obvious? What's not to get?

Hrotbp: I mean I don't get it. What am I looking at? It looks different, but what's the significance of what you've done here?

TN: It might be easier to explain if I add some labels:

The rebuilt stud wall, with labels.

After I tore out the shower liner and the ruined drywall, I discovered that one of the studs in the left wall was friable and mostly rotten. This looked like a combination of water damage and old insect action. I'd known about the insect damage from some work done years ago. It just never occurred to me that the drywallers and the plumber would screw the greenboard into a lousy stud. I used my saber saw to chop out most of this stud, cutting high up into good wood. I also removed the piece that was sitting on the sill plate, which, fortunately, was in good shape.

Hrotbp: What's a sill plate?

TN: It's the horizontal piece of wood that sits on the foundation. It ties the studs together and makes the whole wall one structural unit.

Hrotbp: Oh.

Replacing the sill plate would have been a Pain In The Ass, so I'm glad I didn't need to do it. (Descriptions here are color-coded to match the labels in the photo above.) I installed a new stud, toenailing it in up above into the existing stud and down below onto the sill plate. I also cut spacers to let it stand off an inch from the concrete block wall, so its profile would match the rest of the stud wall.

Maybe at some point, eh?

While I had the wall open, I also cut and fitted some new stretcher pieces made of 2" x 6". This is an upgrade to the wall, in anticipation of future need. Someday, when I am old and feeble, I may need to install a grab bar in this shower. By having these 2" x 6" plates in the wall, I'll not only have a lot of flexibility in positioning the bar, I'll also have an easy time finding solid wood to attach to. If I had to hunt around for studs, I might end up putting a lot of stress on the concreteboard instead of having the person's weight supported by the structural elements of the stud wall itself. That could damage the tile, but more importantly, the grab bar could tear loose under the strain. That could lead to an injury.

I'm far too sexy to have to worry about a broken hip.

As a precursor to installing the fiberglass insulation, I used spray foam to coat the sill plate and the space behind the studs, filling in the gaps between the studs and the concrete block.

Hrotbp: Why? Won't the fiberglass be enough insulation?

TN: This is a bit of extra soundproofing. The noise of the shower goes into the tiles, where it is transmitted through the concreteboard and the studs into the walls behind. Putting this sticky foam on the elements of the stud wall deadens that sound nicely.

Hrotbp: Hey, is all this what you meant by improving the overall performance of the walls?

TN: Yep.

Hrotbp: You're some kinda smart guy, Tony Noland!

TN: Thanks.

Insulating...	... all done.
Starting the concreteboard...	... all done.

I don't have a lot of photos of installing the insulation, mostly because it's a common task that is pretty simple. This is regular R-13 fiberglass, 3.5" thick with a vapor barrier facing. After I had it all cut and stapled in place, I overlaid it with an extra 4 mil plastic sheeting vapor barrier. Since this is a wet application, not just a damp one, it's better to be safe than sorry.

Installing the concreteboard was pretty standard, too. The screws are a little different from drywall screws. Since they have to go through concrete, they have a chisel tip instead of a regular thread point, but they work the same once they're started. I marked the locations of the studs prior to installation so I didn't have any misses or mishaps.

I left a hole for the valve in the insulation...

... and in the concreteboard.

Notice that when I installed the insulation and concreteboard, I left a nice clean hole for the control valve. See the little brass flanges that are sticking up around it? The chrome trim gets attached to those, so you don't want to obscure them. Drilling out new access points after everything is in place is a pain.

Once the concreteboard was in place, I went over all the seams and the screwholes with a polymer waterproofing. This seals up everything underneath the mortar and tiling, and makes the concreteboard into one seamless unit. In the picture below, it's dried to a bright red.

Bright red polymer waterproofing on seams & screwheads.

This shot is actually taken a bit later on, after I've started installing the tiles. More on that in Part 3.

But first, an unexpected problem:


Take a look at the lower right hand corner of the right hand wall. The damage to the drywall was so extensive, I had to cut away a lot of it.

Hrotbp: So?

TN: So, it left a big hole sticking way out away from the studs.

Hrotbp: Yeah, but I see you covered it up with that single piece of concreteboard. It's all one smooth, seamless wall now. What's the problem?

TN: The problem is that the concreteboard is a) thicker and b) much rougher than the drywall.

Hrotbp: Jeez, Tony, that is a problem! How did you get it even, so there wouldn't be a huge, ugly bump in the wall? And how did you get it smooth so you could paint it properly?

All will be revealed in Part 3, which will focus on the installation of the tile, the shelves and the finish work.


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