Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Before
After
Before
After
Before
AfterSchluter Home Additions & ADU: The Los Angeles Owner’s Guide
If you’re searching for Schluter-related help with a home addition or ADU project in Los Angeles, you’ve likely hit a wall: the waterproofing membrane failed, the uncoupling layer cracked, or the shower system you built around isn’t holding up. Penhallow Remodeling installs and repairs Schluter systems as part of larger home addition and ADU projects, with full addition and ADU work typically running $51,300 – $259,600 depending on scope, foundation work, and finish level. Most owners discover a problem the hard way: water staining on a ceiling below, tile cracking at the floor-to-wall transition, or damp drywall behind a shower bench that was never properly waterproofed. We’re a Los Angeles general contractor, not a Schluter affiliate, and we’ll tell you straight what’s fixable and what isn’t.
Key takeaway: Schluter parts are the skeleton of a waterproof room. When one fails, the fix usually means opening the wall or floor back up, not just replacing a gasket. That’s where we start: with a written price and a clear scope, before any demo begins.
Which Schluter Models This Applies To
Schluter makes a family of products that all work together: KERDI waterproofing membrane, KERDI-BOARD for shower walls and benches, DITRA uncoupling mats for floors, DITRA-HEAT for electric radiant floors, and the KERDI-LINE and KERDI-DRAIN systems. The version you have matters enormously. A DITRA mat under a tiled floor in a Los Angeles hillside home behaves differently than KERDI membrane in a second-story ADU bathroom. The compatibility gotcha most Los Angeles owners hit is this: DITRA and DITRA-HEAT are not interchangeable after the fact. If the heating cable was laid over standard DITRA without the right fleece bonding layer, the system fails at the interface, not the cable.
For KERDI systems in showers, the most common point of failure we see is at changes of plane: the inside corners, the drain flange, and the bench-to-wall transitions. Schluter makes pre-formed corners and KERECK strips specifically for these spots. If a previous installer improvised with kerdi-band scraps and leftover thinset, you’ll see cracking there first. We match OEM Schluter parts to the original install where possible. Aftermarket equivalents exist, but for waterproofing layers that sit behind tile and under mortar beds, the OEM part is almost always the right call. The dimensional tolerances and fleece-to-fleece bonding are specific. We’ve pulled apart enough failed showers in Sherman Oaks and Encino to know that the aftermarket swap saves money on the part and costs triple in labor when it delaminates.
Signs Your Schluter Home Addition & ADU Is Failing
- Efflorescence or white crust on grout lines below the shower floor. This usually means water is sitting under the tile instead of routing through the membrane to the drain. The weep holes or bonding flange got blocked or the membrane was punctured during installation. It’s the most common early sign in Los Angeles, where hard municipal water accelerates mineral deposits.
- Cracked tiles in a straight line along a floor-to-wall transition. If the room flexes and the DITRA layer wasn’t bonded properly to a level substrate, the tile breaks at the exact line where the movement concentrated. We see this often in older Valley homes with wood-frame floors that expand and contract with our dry-season swings.
- Damp drywall or peeling paint on the wall behind or below a second-story bathroom. This is a membrane failure you can’t see. Water traveled through a seam that wasn’t lapped with the required 2-inch minimum overlap. By the time you see the stain, the framing behind it has been wet for months.
- Loose or drummy-sounding tiles in an ADU bathroom that’s less than two years old. In the rush to finish an ADU for a rental date, someone hit the thinset window wrong or tiled too soon after membrane installation. The bond failed from day one, it just took time to show.
- Musty smell that doesn’t go away after cleaning. That smell is trapped moisture and, usually, mold inside the wall cavity. It’s not a sealant issue. Somewhere the waterproofing envelope has a hole, and the smell is the first measurable sign.
Replacement Cost & What’s Included
Let’s talk real numbers for Los Angeles. A full Schluter KERDI shower re-do, including demo of the failed tile and membrane, new KERDI-BOARD, new membrane, new drain assembly, tile and grout, runs roughly $5,310 – $14,160 for a standard 3×5 foot shower. If that shower is inside a larger ADU or home addition project, the addition itself carries the bigger number: $53,100 – $153,400 for a conventional addition and $106,200 – $259,600 for a complete ADU build, with Schluter waterproofing specified throughout.
What drives the range on the Schluter repair side: the size of the failed area, whether the subfloor or wall studs need replacement after water damage, and whether the original drain location can be reused. Here’s how the parts and labor typically break down for a shower membrane replacement in Los Angeles:
| Repair Component | Typical Range |
|---|---|
| Demo and haul-away of failed tile and membrane | $950 – $2,950 |
| Schluter KERDI membrane and pre-formed corners | $475 – $1,180 |
| Schluter KERDI-DRAIN or replacement of existing drain | $590 – $1,420 |
| Tile, thinset, grout, and labor | $3,300 – $8,260 |
Every price we give is written, not verbal. The number we hand you before work starts is the number on the invoice. And every Schluter repair or installation carries our 365-Day Done Right Promise: if it’s not done right within the first year, we come back and make it right at no charge. In writing, on every job.
DIY or Call Us?
There’s a safe middle ground. You can check the visible signs: grout cracks, tile movement, water staining, musty smell. You can confirm whether the original installer left behind the Schluter product labels or shower system paperwork, which helps us match parts faster. What you shouldn’t do is cut into the wall or pull up tile to find the leak. Schluter systems fail underneath the tile, and opening the wrong area means you’ve just destroyed the one good section of membrane while the real leak keeps running. Also, if the area involves electrical DITRA-HEAT cable embedded in thinset, leave it alone entirely. A cut cable under a wet floor is a serious shock hazard. We handle the investigation, the waterproofing, and the restoration on every Los Angeles job we take. Call us at (936) 259-2607 and describe what you’re seeing. We’ll walk you through what’s likely happening and give you a written price before any tools show up.
FAQs
A properly installed Schluter KERDI or DITRA system should last 30 to 50 years, but many Los Angeles failures happen at the 5-to-10-year mark, almost always from installation error, not product failure. In coastal neighborhoods like Playa del Rey or San Pedro where salt air and humidity push harder, the tile and grout may need attention sooner, but the membrane itself should still be sound. If yours failed early, the install is the likely culprit, not Schluter. Call us at (936) 259-2607 for a closer look, and we’ll give you a written answer on what failed and what it’ll take to fix it.
Small punctures can sometimes be patched with Schluter KERDI-BAND if the surrounding membrane is still bonded and intact. In practice, though, by the time a Los Angeles homeowner sees the symptom, the damage underneath is usually bigger than the visible spot, often at a seam or corner. We’ll open the minimum area, assess what’s behind the wall, and tell you honestly whether a patch makes sense or a full replacement is the only reliable fix.
For a standard shower, the full job takes 4 to 7 working days: demo, any framing repair, membrane and drain installation, a flood test to confirm waterproofing, then tile and grout. Once the membrane is installed, we do a 24-hour flood test before tile goes in. It’s the step that gets skipped by rushers and the reason we insist on it. Call (936) 259-2607 and we’ll give you a realistic timeline for your specific Los Angeles project.
We keep KERDI membrane, KERDI-BAND, pre-formed corners, and KERDI-DRAIN flanges on hand for repair calls. For larger home addition and ADU projects across Los Angeles, we order the exact Schluter quantity needed for your layout. We also regularly work with other trade brands like KraftMaid cabinetry, Cambria and Silestone countertops, so the full room comes together under one scope and one written price.
Call Penhallow Remodeling for Schluter Repairs in Los Angeles
If your Schluter installation is showing cracks, water stains, or that musty smell that won’t quit, we’ll find out why and tell you exactly what it costs to make it right. Before any work starts, you’ll have a written price and a written guarantee. Trevor Nash and our Penhallow Remodeling team have been working on Los Angeles homes long enough to know the city’s older houses shift and settle in ways that newer builds don’t, and that changes how a waterproofing system needs to be installed. Give me the whole picture first, then we pick up the tools. Call (936) 259-2607 to schedule your free estimate.
Written by Trevor Nash, Owner, Penhallow Remodeling at Penhallow Remodeling, serving Los Angeles and nearby areas.