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Schluter Home Additions & ADU: The Sacramento Owner’s Guide
If you’re planning a home addition or ADU in Sacramento and your contractor has specified Schluter waterproofing and uncoupling systems, you’re looking at a project that typically runs $45,000 to $130,000 for the addition itself, with ADU construction landing between $90,000 and $220,000 depending on size, foundation work, and finish level. We install Schluter systems as part of our remodeling work and can help you understand exactly which Schluter components your project needs, what they cost, and where the real money goes. Most homeowners reach out to us after a previous contractor either skipped Schluter entirely or used it incorrectly, and now they’re staring at a failed shower pan or cracked tile over a newly framed addition.
The most common discovery path is this: you’re adding a bathroom or ADU kitchen, tile starts cracking at the seams, or water shows up on the ceiling below. You pull up the invoice and find the contractor used plain drywall behind the shower tile instead of a Schluter KERDI membrane, or skipped the DITRA underlayment under floor tile over wood subfloor. Now you need a fix that actually holds, and you’re wondering whether the whole addition needs to come apart. It usually doesn’t, but the repair has to be done right.
Which Schluter Models This Applies To
Schluter makes a full line of waterproofing and uncoupling products that matter specifically in additions and ADUs. The big three we deal with in Sacramento additions are KERDI (waterproofing membrane for showers and wet walls), DITRA (uncoupling underlayment for tile floors over wood subfloor), and KERDI-BOARD (waterproof foam backer for shower walls). Each one has specific thicknesses and application ratings. KERDI membrane comes in rolls at 6’7″ wide, with KERDI-BAND for seams and corners. DITRA is 1/8″ thick and pairs with DITRA-HEAT if you want a warmed floor. KERDI-BOARD runs from 3/16″ up to 2″ thick depending on structural need.
Here’s the compatibility gotcha most homeowners never hear: Schluter products only carry their warranty when installed with Schluter’s own thin-set mortar, or an approved unmodified mortar, on the correct substrate. If your previous contractor set KERDI over drywall using a modified mortar, or skipped the KERDI-BAND at the floor-to-wall seam, the system wasn’t installed to spec and Schluter’s warranty won’t apply. That means the repair is on you unless the contractor stands behind it. We see this constantly in ADU builds done on the cheap. The fix isn’t to rip out Schluter and hope for better; it’s to install the right Schluter component correctly. We stock KERDI rolls, KERDI-BAND, DITRA, and KERDI-BOARD on our trucks for exactly this kind of repair work in Sacramento.
Styles & brands we work with
Signs Your Schluter Home Additions & ADU Is Failing
- Tile cracking along floor seams in your ADU kitchen or bathroom. This usually means no uncoupling membrane was installed between the tile and the wood subfloor. Wood expands and contracts with Sacramento’s temperature swings, and the tile grinds against itself without DITRA underneath.
- Water staining on the ceiling below a second-story bathroom addition. A failed or missing KERDI seam at the shower pan or curb lets water through slowly. By the time you see the stain, the subfloor has been wet for months.
- Mold or mildew smell that won’t leave, even after cleaning. Water is trapped behind tile that was set over drywall without KERDI. The grout looks fine, so you clean the surface, but the smell returns because the moisture is inside the wall cavity.
- Grout darkening or staying wet in patches near the shower floor. This points to a failed shower pan membrane or no KERDI-BAND at the pan-to-wall transition. Water is pooling under the tile instead of draining to the weep holes.
- Hollow-sounding tile or visible movement when you step on certain spots. The thin-set has lost bond, often because it was applied over a dirty or improperly prepped substrate, or the wrong mortar was used. The tile will eventually crack through.
See the difference
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After
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AfterReplacement Cost & What’s Included
For Sacramento homeowners, repairing or replacing Schluter waterproofing in an addition or ADU generally runs $3,500 to $12,000 for a full shower pan and wall membrane replacement, depending on demo scope, whether we’re pulling tile or just the pan, and how much subfloor repair is needed. A full gut-and-rebuild of an ADU bathroom with new KERDI, tile, and fixtures lands in the $9,000 to $28,000 range. The $45,000 to $130,000 figure for complete home additions covers the entire project, not just the Schluter portion.
What drives the cost up: how much tile has to come out, whether the subfloor is rotted and needs replacement, and whether we’re matching existing tile or starting fresh with new tile. What drives it down: catching the water damage early, before structural framing is involved. Every repair we do includes a written price before we start, a written guarantee on the work, and our 365-Day Done Right Promise. If the repair fails inside a year, we come back and fix it at no charge. That’s in writing, not a verbal handshake.
DIY or Call Us?
Schluter waterproofing is not a place to save money with a YouTube tutorial. The materials are simple to understand, but the failure point is in the details: proper thin-set coverage, KERDI-BAND overlap at every seam, correct mortar selection, and a water test before tile goes up. Get one of those wrong and you’ve built a slow leak into your new addition. You can safely inspect what you have: check grout for darkening, look for cracks around the shower pan perimeter, and tap tile to find hollow spots. But if you find a problem, call a pro. Call us at (279) 300-1177 and we’ll come look at it. The estimate is free, and the price we quote is the price you pay.
FAQs
Schluter KERDI and DITRA systems are engineered to last the life of the building when installed correctly, which in practical terms means 30 to 50 years. The failures we see in Sacramento are almost always installation errors, not product failures, usually within the first five years.
Sometimes, yes. If the failure is limited to the pan and the lower course of wall tile, we can often demo just the pan, replace the KERDI, water-test it, and re-tile the floor and curb. If water has wicked up the walls behind the tile, the repair scope grows. Call (279) 300-1177 and we’ll tell you which situation you’re in.
A shower pan replacement typically takes 4 to 6 working days including water testing and tile. A full shower rebuild runs 1 to 2 weeks. We give you a written schedule with the written price, and we show up in the window we gave you.
We stock KERDI membrane, KERDI-BAND, DITRA, DITRA-HEAT, and KERDI-BOARD on our trucks throughout Sacramento. You don’t need to source anything. We also install products from other trade brands like KraftMaid, Cambria, and Silestone, so the finish work matches the waterproofing underneath.
Written by Trevor Nash, Owner, Penhallow Remodeling Sacramento at Penhallow Remodeling Sacramento, serving Sacramento and nearby areas.
