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Plant Prefab Bathroom Remodeling: The San Diego Owner’s Guide
A Plant Prefab bathroom remodel in San Diego typically costs between $10,620 and $33,040 installed, depending on the size of the bathroom, what you’re replacing, and how much the original factory waterproofing has deteriorated. We stock plant prefab-compatible waterproofing systems, shower pans, vanities, and fixtures on our trucks, and most parts can be matched and ordered same-day from our Carlsbad suppliers. The symptom that usually brings Plant Prefab owners to us is a soft spot in the shower floor or water staining at the wall-to-pan seam, which means the factory waterproofing membrane has failed and moisture is moving through the assembly.
If you’re smelling must in a Plant Prefab home bathroom or your shower tiles have started lifting, you’re not losing your mind. Factory modular bathrooms have precise tolerances, and once the waterproofing goes, the damage spreads fast through the prefab subfloor. We’ll walk through what’s wrong, what it costs, and what we do to fix it so you don’t have to tear out the whole pod.
Which Plant Prefab Models This Applies To

We work on bathrooms in all Plant Prefab housing lines that ship a prefinished wet-wall or full bathroom pod, including the LivingHome series and custom ADU configurations installed throughout San Diego County. The factory-built bathroom pods use either a fiberglass-reinforced acrylic shower pan or a tile-over-cement-board assembly, and the compatibility gotcha is this: the drain rough-in for the factory pan is often 2 inches off a standard Kohler or Moen off-the-shelf replacement. A lot of owners buy a retail shower base, find it doesn’t line up with the prefab drain stub, and end up paying a plumber to move framing that shouldn’t have been touched.
We identify what you have by the label under the vanity or inside the access panel and by measuring the pan flange and drain offset. Aftermarket parts often work fine, but for waterproofing membranes and shower pans we prefer OEM-spec products and compatible trade lines we trust, like Schluter Kerdi for re-waterproofing and Cambria or Silestone if you’re redoing vanity tops. If you have a factory-installed KraftMaid vanity, we can match existing cabinetry rather than replacing the whole wall run.
Styles & brands we work with







Signs Your Plant Prefab Bathroom Remodeling Is Failing
- Soft spots around the toilet flange or shower pan edge. In San Diego’s coastal moisture, the prefab subfloor wicks water along fasteners once the vinyl sheet or tile membrane is compromised, softening the OSB.
- Tiles popping or grout crumbling along the factory seam. Plant Prefab pods flex slightly in transit, and that seam between the factory wall and site-set floor is the most common failure point we repair.
- Musty smell that won’t go away even after airing out. This means water has breached the membrane and is sitting under the floor, feeding mold in the underlayment.
- Shower valve or mixing valve losing pressure without a visible leak. Factory-installed fixtures are accessible through the access panel but often fail at internal cartridge seats, which is a simple part swap if caught early.
- Corrosion at the wall-hung sink brackets or vanity kick plate. That’s bulk water finding the metal anchors, not condensation, and it means the wall cavity behind the vanity is wet.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included

The installed price to remodel a Plant Prefab bathroom in San Diego runs $10,620 – $33,040, and most jobs land between $14,000 and $22,000 when you’re redoing a shower, replacing the pan, re-waterproofing, and installing new tile, fixtures, and a vanity. On the lower end, say $10,620 to $14,160, you’re looking at a tub-to-shower conversion or small bathroom where the subfloor is intact and the valve just needs a new cartridge and trim. The upper end covers full wet-wall rebuilds with floor damage, relocating a drain, and custom glass enclosures sourced from local fabricators.
Every quote includes tear-out, disposal, plumbing, waterproofing, tile, fixture install, and a written line-item price before any work starts. If the factory pan can be salvaged, we’ll say so and charge you less. The written price you sign is the invoice at the end, and the whole job carries our 365-Day Done Right Promise: if something fails within the year, we come back and fix it free.
DIY or Call Us?
You can safely check the access panel, look for moisture staining, and run the shower while feeling the drywall seams next to the pan for heat or softness. What you shouldn’t do is cut into a prefab wall to find the leak. Plant Prefab pods route drain lines and electrical in narrow chases, and one wrong cut into a factory romex run or supply line turns a $1,500 repair into a $7,000 opening of the wall. Waterproofing is also not a caulk-and-walk job: covering over a failing membrane with sealant just traps water deeper in the assembly.
If you’ve got water where it shouldn’t be, call (619) 604-9624. We’ll come out, find the leak, write you a price for exactly what needs fixing, and leave the rest alone.
FAQs

Most Plant Prefab bathroom remodels we do in San Diego take 10 to 21 working days from tear-out to final caulk, depending on whether the subfloor needs replacement and whether custom glass is open on the fabricator’s schedule. We give you a written arrival window before we start and keep the work area sealed off so the dust stays out of the rest of the house.
Sometimes, yes. If the factory pan flange is intact and the subfloor is dry, we can replace the pan and regrout the lower wall tile without touching the rest of the bathroom. We’ll tell you if full replacement is the only honest fix, and the written quote will show you the difference so you can decide. Call (619) 604-9624 for an exact quote.
We keep most waterproofing materials, valve cartridges, and trim kits on our trucks, and our San Diego suppliers stock Kohler, Moen, and Delta parts we can pull same-day. Specialty prefab shower pans and KraftMaid vanity faces typically arrive within 3 to 5 business days.
No. The price we write on your quote is the number on your invoice unless we open the wall and find water damage we couldn’t see from the outside, and even then, we stop, show you what we found, and get your written sign-off before spending another dollar. That’s the Kingswell Way: say the price before the work. Show up in the window we gave. Leave the place cleaner than we found it.
If your Plant Prefab bathroom is showing water damage and you want a real number instead of a vague range, call (619) 604-9624. We’ll come out, look it over, and write you the price for exactly what needs doing. Tell me what you need, I’ll tell you what it costs, and we’ll go from there.
Written by Trevor Nash, Owner, Penhallow Remodeling San Diego at Penhallow Remodeling San Diego, serving San Diego and nearby areas.


