Sometimes, you need to nuke it from space
It’s the only way to be sure, after all. This post describes a partial full-nuke shower replacement process. While nuking all the tile turned out to be a necessity, it was still possible to replace basically the entire shower without replacing the existing custom glass enclosure and shower door. This saved several thousand dollars, which was nice. Shower glass is very expensive. Re-use it whenever possible.
Embarking on a shower fix attempt is always risky. Without x-ray vision, it’s impossible to know beforehand just how a shower base has been constructed. Tiled walls can offer lots of clues and opportunities for peeking at the substrate without tearing things up. But tiled floors? No such luck without that x-ray vision super-ability.
The visual symptoms were pretty bad though, even looking past the poor previous tile choices (dark textured tile for a shower wall? Really?).
First, the shower floor had standing water dead spots (made worse by the irregular pebble material). Second, the closet on the other side of the shower wall smelled of mildew. Third, the shower itself smelled of mildew. And fourth, the pebble tile floor of the shower was loose with cracked and missing grout.
None of these things are good, and taken all together suggested failed shower pan waterproofing. However, although the shower and adjacent closet smelled mildew-y, there was no sign of structural water damage. Also, there was no sign of water wicking thorough the shower curb. So, I figured there was a good chance the shower could be fixed by taking up the tile and concrete base to expose and repair the (probably fiberglass, I thought) shower pan lining. Wouldn’t change the not so great wall tile choice, but at least would take care of the structural waterproofing problems.
A chance of avoiding a complete custom frameless glass and granite sill enclosed custom shower redo? The clients figured that was worth a gamble.
Figuring the underlying problem (pun intended) was ‘simply’ badly laid shower floor tile and a small hole or two in the shower pan waterproofing, a fix was probably possible without tearing into the walls. Just five straightforward steps:
- Carefully chip out the existing floor tile and concrete underlayment
- Repair any nail holes, cracks, or open seams in the shower pan waterproofing liner with proper sealant
- Replace the concrete mortar bed with a proper slope to the drain
- Re-tile the shower floor with properly mixed thinset and grout
- Triple-seal the shower floor grout for maximum moisture resistance
Again, the goal was to avoid tearing into the walls for three reasons.
First, whoever had installed the original tile used concrete backerboard on the walls (checked by simply popping off the shower valve cover plate) and managed to set 12″x24″ tile with 1/8″ grout lines to pretty close on flush. This was a sign they were at least conscientious.
Second, with no visible moisture wicking through the shower base, the shower pan liner waterproofing was most likely doing its most important job of keeping water mostly inside the shower space.
And third, the shower configuration with granite sills and frameless glass integrated with a garden tub would have made complete replacement super expensive. Good rule of thumb — make the first master bath custom frameless glass on granite sill enclosed shower you buy last for at least a few decades. Redoing ’em completely costs out about equal to a full first year of tuition to a good in-state college.
Replacing just the shower base, floor, and curb had a good chance of fixing the problems for at least a decade. And, this conservative plan could (with some skill on the curb tile) be done without touching any of the wall tile or custom glass — the most expensive parts.
The Dangers of (bad) DIY
Unfortunately, the person who’d originally done the shower construction was (as I eventually discovered) a do-it-yourself-er who missed a few crucial details from the YouTube tutorials. For example, things like the fact that you can’t tile directly on top of PVC vinyl shower liners.
All the material ingredients for a great functioning shower were used, just bizarrely wrongly. Like, putting icing on a cake before baking it bizarre. Taking up the shower floor tile showed quickly that the walls were going to have to go too.
The shower floor tile was laid directly on top of a PVC vinyl shower liner, which was laid on top of a (badly) presloped layer of concrete. That explained both why the tile was coming apart and the bad drainage. Further excavation showed that there were actually two layers of PVC liner waterproofing, with one layer haphazardly glued on top of another layer. This was apparently the DIYer’s solution to patching some tears in the underneath liner. Problem is, this ensured that a layer of moisture would be permanently trapped in the shower base — explaining the permanent musty smell.
Finally, the PVC liner layers were put in after the concrete backerboard wallboard was installed, which meant that the first foot or two of wall tile was laid directly on plastic (not good). So, condensation collecting on the backside of the concrete wallboard was wicking down underneath the shower base waterproofing.
Sometimes, you get unlucky with a potential half-measure fix. The bizarrely odd shower construction I discovered was definitely unlucky. The whole thing had to go. However, it would still be possible to take the walls down to the studs without replacing the glass.
The (new) Plan (B)
How to completely replace a shower without completely replacing all the shower? Turns out it’s doable in six careful steps:
- Carefully remove the existing frameless glass door (VERY carefully, since they weigh a ton and cost ~$700 to replace)
- Carefully demo not just the shower floor base but also all the wall tile and concrete backerboard substrate
- CAREFULLY work around the existing granite sills during the demo, so as to not crack the existing granite (which is a naturally waterproof dense stone).
- PRECISELY replace the concrete backerboard and wall tile to the EXACT same dimensions as before (since being off by even 1/8″ would mean needing a new custom glass door)
- Rebuild the shower base with proper waterproofing and properly installed floor tile
- CAREFULLY re-install the original frameless glass door (and hope it fits!)
Not the easiest approach, especially with the whole 1/8″ tolerance in every dimension thing. But again, preserving the original granite sills and enclosure glass (and re-using the original glass door) would save thousands in materials costs. Plus, no more musty shower. AND, an opportunity for way better looking (and more practical) tile choices.
The client was game, so we gave it a shot.
A very happy client with a properly waterproofed (and way better looking) new shower at half the cost of replacing everything. Even managed to get the tile dimensions perfect enough for the original glass door to actually fit better than it did before.
Need a creative cost-saving fix for a bizarrely odd shower install problem? I know a guy who can do that …
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