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Schluter Home Additions & ADU: The Los Angeles Owner’s Guide
If you’re planning a home addition or ADU in Los Angeles and want Schluter waterproofing and uncoupling systems specified into the build, a full project typically runs $53,100 – $153,400 installed, depending on square footage, foundation work, and finish level. That’s the honest range we give homeowners before a single drawing is signed. Most owners come to us after discovering their existing addition or ADU has a failed waterproofing layer behind tile, rotted substrate at the curbless shower, or cracked floor tile from a slab that was never properly isolated. The fix usually isn’t a patch. It’s pulling back to a sound substrate and rebuilding the waterproofing envelope correctly, whether that’s a new KERDI membrane shower assembly, DITRA uncoupling over a cracked slab, or full re-flash at the transition between the main house and the addition.
We’re an independent Los Angeles remodeling contractor. We are not affiliated with Schluter Systems. What we are is a crew that has torn out enough failed shower pans and cracked tile floors to know exactly why the Schluter product was specified in the first place, and exactly how to install it so it does what the manufacturer says it will do.
Which Schluter Products Apply to Home Additions & ADUs
This isn’t a single part. A Schluter spec inside a home addition or ADU involves a system, and getting the layers right is what separates a bathroom that lasts from one that fails in three years. The products we install most often in Los Angeles additions and ADU projects fall into three families: KERDI membranes (KERDI, KERDI-BAND, KERDI-FIX, and the pre-sloped KERDI-SHOWER trays), DITRA and DITRA-HEAT uncoupling membranes for tile floors, and the DILEX movement joints and profiles that terminate tile edges cleanly. The compatibility gotcha most owners don’t see coming is this: a curbless walk-in shower in a Los Angeles ADU almost always requires recessing the subfloor to get the KERDI tray to flush out with the bathroom floor. On a slab-on-grade ADU, that’s a concrete cut. On a raised foundation addition, that means notching or dropping joists. Contractors who skip this step end up with a lip at the shower entry, and the homeowner ends up with a trip hazard and a leak path at the threshold.
When you’re looking at an existing Schluter install and trying to figure out what failed, look for the orange. KERDI is unmistakable. If you see KERDI-BAND peeling at a seam, or DITRA matting pulling away from the thinset bed, the failure is almost always installation-related, not product-related: the thinset was mixed too dry, the membrane wasn’t keyed into the mortar, or the seams weren’t embedded with the proper two-inch overlap. That’s the reality we see across Los Angeles, from West Adams to the Valley: Schluter products fail when the installer skips a step the datasheet clearly spells out. Curtis Lane grew up watching his grandfather re-frame a back bedroom in Crenshaw that never stayed square, which is why our crews don’t skip the datasheet. We read it, we follow it, and we write the scope so you can hold us to it.
For aftermarket parts and compatible equivalents, the honest answer is that for waterproofing membranes, we don’t substitute. KERDI is KERDI. There are lesser sheet membranes on the market, and we’ve torn them out. DITRA has competitors too, and some are fine. But when the spec says Schluter, we install Schluter and price it as Schluter. The brands we stock and install alongside it, KraftMaid for cabinetry in the ADU kitchen, Cambria or Silestone for the countertops, those we’ll show you as documented options. But the waterproofing layer is not where you save money on a Los Angeles ADU. The demolition and rebuild cost to fix a failed shower pan is $8,000 – $15,000 on its own. That’s the expensive way to learn that a cheaper membrane wasn’t cheaper.
Styles & brands we work with
Signs Your Schluter Home Addition or ADU Envelope Is Failing
- Efflorescence or water staining on the ceiling below the addition’s bathroom. White chalky residue or a brown ring means water is finding a path through a KERDI seam or a failed DILEX corner joint. The leak is rarely where the stain is. Water travels the substrate and drips at the low point.
- Cracked floor tile in a straight line across the ADU slab. A crack that runs in a continuous line is a slab movement crack, and it means the DITRA layer either wasn’t installed, wasn’t lapped correctly, or the tile was bonded directly to concrete. Los Angeles clay soil expands and contracts with rain and drought. We see this in Leimert Park and Echo Park regularly.
- Grout cracking at the change of plane in a shower. Tile corners move independently. If there’s no DILEX movement profile and no KERDI-BAND at the corner, the grout is doing a structural job it was never designed to do. It fails, then water gets behind the tile.
- Musty smell in the ADU that won’t go away with ventilation. A persistent odor means the waterproofing envelope is compromised somewhere. By the time you smell it, the damage behind the wall or under the floor is already underway.
- Hollow-sounding tile in the shower or on the bathroom floor. Tap a quarter on the tile. A hollow thud means the thinset has lost bond, or was never properly bonded in the first place. A KERDI install that’s debonded is a waterproofing failure waiting to leak.
What a Home Addition or ADU Costs in Los Angeles
A full home addition in Los Angeles runs $53,100 – $153,400. A garage conversion to an ADU runs $35,400 – $94,400, and a new detached ADU starts around $106,200 and can push past $259,600 depending on site conditions, utility trenching, and the finish package. Those numbers include the Schluter waterproofing system installed correctly, because we don’t separate it out as an upsell. It’s in the scope. Every line item is written down, from the KERDI membrane and KERDI-BAND footage to the DITRA under the tile to the DILEX profiles at the floor transitions. The price we give you before the work starts is the price on the final invoice. That’s The Garrison Standard: no numbers that move at the door, no change orders because we forgot to price a shower pan.
What drives the range on any addition or ADU in Los Angeles is the foundation condition and the rough plumbing runs. A raised foundation with accessible joists costs less to tie into than a slab that needs cutting. A bathroom that backs up to an existing wet wall costs less than one where we’re running a new drain line across the footprint. Every Bradford Remodeling project carries the 365-Day Done Right Promise in writing. If the Schluter waterproofing or any part of the work fails within a year of completion, we come back and correct it at no charge. You get the signed guarantee in your hand at close of job.
See the difference
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AfterDIY or Call Us?
There are things a Los Angeles homeowner can reasonably check before calling us. Look for cracked grout. Feel for loose tile. Run a 24-hour flood test on your shower pan if you suspect a leak and mark the water level. What you should not do is peel back KERDI membrane to “see what’s underneath,” because once you break that seal, you can’t re-create it without removing the surrounding tile. The waterproofing layer is a continuous system. Cutting into it to inspect is how small leaks become full shower rebuilds. If you’re building new, don’t pour the slab or frame the walls without knowing exactly where the Schluter system starts and stops. The rough-in sequences are unforgiving. We sequence demo to drywall so the waterproofing goes in at the right stage, before tile and before trim, not retrofitted after the fact. Straight number, real scope, no surprises at the punch list. Call (903) 568-7222 and we’ll walk the site and tell you exactly what you’re looking at.
Schluter Home Addition & ADU FAQs
A properly installed KERDI or DITRA system should last 25 years or more, essentially the life of the tile assembly. The product doesn’t degrade on its own in our climate. What fails is the installation: bad thinset coverage, skipped seam embedding, or movement stress that the system wasn’t designed to absorb. Call (903) 568-7222 if you suspect the install, not the product, and we’ll verify it.
In most cases, no. A failed seam or compromised membrane requires removing tile and substrate back to a sound surface, then reinstalling the waterproofing envelope as a continuous layer. Patching KERDI over a failed section doesn’t restore the waterproofing in a way we’d stand behind with a one-year written guarantee. The honest fix is a rebuild, and we’ll price it before we start.
Most shower rebuilds in an addition or ADU take two to three weeks once demo starts. That includes substrate repair, membrane installation, a 24-hour flood test, tile setting, and grout curing. We don’t rush flood tests. A leak you catch at the flood test costs a day. A leak you catch after tile is set costs a full do-over. Call (903) 568-7222 for a written timeline on your specific project.
We stock KERDI, KERDI-BAND, KERDI-FIX, DITRA, and DILEX profiles as standard truck inventory for our crews. Specialty items like pre-sloped KERDI-SHOWER trays in non-standard sizes or DILEX profiles in uncommon finishes are ordered directly from our Los Angeles Schluter distributor, usually next-day. We don’t run your job off store stock and we don’t substitute unknown membranes. Call (903) 568-7222 and we’ll tell you what’s in the truck and what’s one day out.
Written by Curtis Lane, Owner, Bradford Remodeling at Bradford Remodeling, serving Los Angeles and nearby areas.
Get a Written Price Before Any Work Starts
If you’re planning a home addition or ADU in Los Angeles, or you’re looking at what you suspect is a failed Schluter waterproofing install, call (903) 568-7222. We’ll walk the site, write down exactly what we see, and hand you a flat-rate scope of work with every line item priced before you spend a dollar. The Garrison Standard means the number we give you is the number on the final invoice, guaranteed in writing, and covered by the 365-Day Done Right Promise for a full year after completion. A real person answers the phone, day or night.
