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Schluter Home Additions & ADU: The West Covina Owner’s Guide
Schluter home additions and ADU projects in West Covina typically run $45,000 to $130,000 installed, depending on square footage, site prep, and which Schluter waterproofing and uncoupling systems your build requires. We match Schluter specs exactly on every job we take, whether that means KERDI-BOARD subassemblies for a bathroom inside the new addition or DITRA-HEAT under tile in a full ADU kitchen. Most owners find us because their existing Schluter install is failing somewhere they can see: cracked grout at a shower bench, water staining on a ceiling below, or tile that’s loosened at the floor edge where membrane was cut too short.
You should know what you’re getting before we ever pick up a tool. That’s how we run every Schluter-related addition and ADU job in West Covina – written price first, name and photo of every crew member before they arrive, and a 365-Day Done Right Promise on the completed work.
Which Schluter Models This Applies To
Schluter makes several product lines that show up inside additions and ADUs, and each one has compatibility rules that matter when something fails. The most common in West Covina builds are:
- KERDI waterproofing membrane and KERDI-BOARD – used for shower walls, tub surrounds, and wet-area backing. Failures here usually come from improper thinset coverage at seams or missing KERDI-BAND at a corner. If tile is already set, matching the existing build means knowing whether the original installer used KERDI or KERDI-DS, because the bonding requirements differ.
- DITRA and DITRA-HEAT uncoupling membranes – installed under tile floors to absorb movement between substrate and tile. In West Covina’s clay-heavy soil, slab movement is a real factor, and a DITRA layer that wasn’t pressed fully into wet thinset will telegraph cracks through the tile within a few years.
- Schluter trim profiles – the metal strips that cap tile edges at thresholds, niches, and countertops. These aren’t structural, but a bent or corroded profile means water has a path behind the tile, and that’s when the real damage starts.
OEM Schluter parts are what we install on any addition or ADU repair. There are generic aftermarket membranes and trims on the market, and we’ve pulled enough of them out of failed jobs to know the savings don’t hold up. Schluter publishes exact spec sheets for every product, and we match the part number to the build before anything gets ordered. Mason Remodeling Co West Covina is an independent contractor and not affiliated with Schluter, but we’ve built and repaired enough Schluter-spec enclosures to know which part belongs where without guessing.
Styles & brands we work with
Signs Your Schluter Home Additions & ADU Is Failing
- Grout cracking along a shower floor or bench seam. This often means the KERDI membrane underneath has delaminated from the substrate, and the tile is now moving independently. The crack is the first visible symptom of a waterproofing layer that’s no longer doing its job.
- Water staining on the ceiling below a second-floor bath. By the time stain shows, water has found a path through a failed seam or a screw penetration that was never covered with KERDI-BAND. The leak usually starts small and runs along a joist before it pools anywhere visible.
- Tiles that sound hollow when tapped. Hollow-sounding tile over DITRA or KERDI means thinset coverage was incomplete when the tile was set. The membrane might be fine, but the tile bond is failing, and eventually the tile will crack or come loose.
- Efflorescence or white crust at tile edges. That crust is mineral salts left behind by water migrating through the tile assembly. It’s not cosmetic – it’s evidence that moisture is moving through a layer that Schluter designed to be waterproof.
- A metal profile pulling away from the tile edge. Schluter trim profiles are embedded in thinset and should stay tight for decades. If one is lifting, the thinset bed under it has failed, which usually means water intrusion at that point has been ongoing.
See the difference
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AfterReplacement Cost & What’s Included
For a Schluter-related repair inside a West Covina addition or ADU, your price depends on how much of the assembly has to come apart. Here’s what we see in this market:
- Spot repair of a KERDI seam or small membrane section: $800 – $2,500, including demolition to the affected area, new KERDI and KERDI-BAND, and retiling.
- Shower pan membrane replacement: $3,000 – $8,500, which means removing the shower floor and the first course of wall tile, replacing the pan membrane and KERDI-BAND at all transitions, and reinstalling tile and grout.
- Full Schluter shower rebuild: $4,500 – $12,000, for a complete tear-out to the studs, new KERDI-BOARD walls, new pan, new tile, and new trim profiles.
- DITRA or DITRA-HEAT replacement under a floor: $2,000 – $6,500 depending on square footage, whether heating cable is involved, and whether we’re reusing existing tile or installing new.
Every quote includes parts, labor, demolition, disposal, and the Schluter-spec installation materials. What drives the top of the range in West Covina is usually access – second-story ADUs, tight lot line setbacks, or substrate repair that wasn’t visible until we opened the wall. We write the price before work starts, and that price doesn’t change unless you change the scope. The work is covered by our written guarantee for 365 days from completion. If something isn’t right in that window, we return and fix it at no charge.
DIY or Call Us?
A homeowner can safely check a few things before calling: look for cracked grout, tap tiles to find hollow spots, and check for staining on ceilings below wet areas. What you shouldn’t do is cut into a Schluter assembly yourself. Once tile is removed and membrane is exposed, you’re making a decision about waterproofing continuity that either works or leaks. We’ve repaired jobs where a well-meaning owner pulled up loose tile, patched it with mastic from a big-box store, and created a moisture sandwich that made the underlying damage worse within months. If water has been getting in, the framing behind it needs to be inspected by someone who knows what water damage looks like in San Gabriel Valley construction. Call us at (707) 760-7579 and we’ll take a look. The estimate is free, and you’ll get a written price before any work begins.
FAQs
A properly installed Schluter waterproofing or uncoupling membrane should outlast the tile job itself – 25 years or more in West Covina conditions. The catch is that clay soil movement around the San Gabriel Valley can stress any tile assembly, and membrane failures we see are almost always installation mistakes, not product failures. That’s why we verify what’s behind the tile before we quote a repair.
Call (707) 760-7579 if you suspect a Schluter failure in your addition or ADU – we’ll tell you what we’re seeing and what it costs to fix.
A small seam failure can sometimes be repaired by opening that area, replacing the membrane section, and rebanding the seams, but the repair is only as good as the bond to the remaining membrane. If the original install used the wrong thinset or the membrane wasn’t embedded correctly, patching one spot often means the rest of that wall or floor is on borrowed time. We’ll tell you honestly which situation you have once we open the wall. Estimates are free at (707) 760-7579.
A spot repair on a KERDI seam usually takes one day of demolition and prep, one day of membrane installation and flood testing, and a day or two for tile and grout, so figure three to four working days. A full shower rebuild runs one to two weeks, and a DITRA floor replacement is typically three to five days. We schedule the exact timeline in writing before work starts, and Isaac Pruett keeps those schedules honest – if something changes, you hear about it before it happens, not after.
We keep common Schluter profiles, KERDI-BAND, and membrane stock on hand for repairs, and we order exact-match product lines for larger rebuilds from our local supply chain, typically arriving within one to two business days in West Covina. If your addition or ADU uses an older or discontinued Schluter profile, we’ll source the current equivalent and confirm compatibility before we break ground. We also work with KraftMaid, Cambria, and Silestone products for the finishing stages on additions and ADUs, so your whole project stays on one schedule.
Call (707) 760-7579 to schedule your free estimate for any Schluter home addition or ADU project in West Covina.
Written by Isaac Pruett, Owner, Mason Remodeling Co West Covina at Mason Remodeling Co West Covina, serving West Covina and nearby areas.
