Schluter Home Additions & ADU Nationwide

Schluter Home Additions & ADU: The Los Angeles Owner’s Guide

Schluter home additions and ADUs in Los Angeles typically run $53,100-$153,400 installed, depending on square footage, foundation work, and finish level. We stock Schluter waterproofing membranes, KERDI-BOARD, DITRA-HEAT, and edge profiles on our trucks, so if a failed part is holding up your addition, we can usually match it the same visit. Most Los Angeles owners discover a Schluter part failure the way they discover a bad head gasket: a small water stain on the ceiling below a new bathroom, a cracked tile at a KERDI seam, or a damp smell in a new ADU that shouldn’t be there.

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Rowan Construction Group is an independent contractor, not affiliated with Schluter Systems. We install and repair Schluter products daily, which means we know how they behave in Los Angeles heat, hard water, and seismic movement.

Which Schluter Models This Applies To

Schluter makes a precise system for tile and waterproofing, and each part has a specific job. The parts we most often replace or install in Los Angeles home additions and ADUs break into four families:

• KERDI waterproofing membrane and KERDI-BAND. Used on shower walls, bathroom floors, and any wet area. The membrane comes in rolls; KERDI-BAND seals the seams and corners. Failures here show up as leaking showers or water damage at the curb.
• KERDI-BOARD panels. Foam-core backer board that replaces cement board. Thicknesses run 5/16 in. to 2 in., and the thinner panels are easy to mis-spec on a load-bearing bench or grab-bar wall. That’s a compatibility gotcha we check on every quote.
• DITRA and DITRA-HEAT underlayments. Uncoupling membranes for tile floors. DITRA-HEAT adds a heating cable system. In Los Angeles, DITRA is common in ADU bathrooms and kitchens; if the heating cable fails, the repair is a full floor section replacement, not a patch.
• Schluter profiles and drains. Edge profiles (SCHIENE, QUADEC, DECO) and linear drains (KERDI-LINE). Drains are the part we see fail most often in Los Angeles ADUs, usually at the membrane-to-drain collar connection, not the drain body itself.

To identify what you have, look for the printed Schluter label on the membrane edge or the profile end cap. If it’s buried, we can check the material thickness and orange coloring. For OEM versus aftermarket: Schluter’s warranty covers the system only when all components are genuine Schluter. Some aftermarket membranes exist, but mixing brands at a seam voids the Schluter warranty and creates a joint that no manufacturer stands behind. We stock genuine Schluter parts specifically because the warranty math is that simple.

Signs Your Schluter Home Additions & ADU Is Failing

• Water staining on the ceiling below a new bathroom. This usually means a KERDI seam or corner wasn’t fully bonded, or the KERDI-BAND wasn’t embedded into the thinset correctly. The membrane itself rarely fails; the installation detail does.
• Tile cracks in a diagonal line across the floor. DITRA’s whole job is to let tile move independently from the substrate. A diagonal crack suggests the membrane wasn’t extended far enough, or the substrate below it (plywood or concrete) is moving more than the uncoupling layer can absorb.
• Grout cracking at the shower curb or bench. KERDI-BOARD benches and curbs flex if not properly braced. The flex transfers to the grout line first. Left alone, water gets behind the tile.
• A damp, musty smell in the ADU that gets worse after rain. In Los Angeles, we see this most often in ADUs built over garages or on slab foundations. It can mean the waterproofing detail at the floor-wall transition wasn’t done, or a Schluter drain body shifted during the slab pour.
• The linear drain cover sits uneven or rocks underfoot. KERDI-LINE drains have a support frame that must be set level before tile goes in. If the frame moved, the cover never sits right, and the membrane bond at the drain collar is compromised.

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Replacement Cost & What’s Included

For a Schluter part replacement inside an existing Los Angeles home addition or ADU, the installed cost depends on how much of the surrounding tile, substrate, and trim has to come out to reach the failed part:

• KERDI seam or corner repair: $470-$2,950, depending on access. If the shower floor has to come up to re-bond a seam, the tile replacement is most of the cost.
• DITRA-HEAT cable or mat replacement: $2,360-$7,670. The membrane and tile come out, the new mat goes in, and the floor goes back. This is a controlled demolition job, not a patch.
• Linear drain collar repair or replacement: $945-$3,540. If the drain body itself is cracked, the repair goes to the higher end because the waterproofing bond has to be rebuilt from the collar up.
• New Schluter system installed as part of a home addition or ADU: $53,100-$153,400. This is the full project range, and the waterproofing detail is a line item in the written scope, not an extra.

Every Rowan Construction Group quote includes the Schluter part cost, the labor to get to the failure and put the tile back, and the written warranty on our work. The flat price is written before work starts, under Clause 1 of The Haven Standard. No change proceeds without a signed change order, so the number you’re quoted is the number you’ll pay unless you approve something different.

DIY or Call Us?

If you’re trying to figure out whether a Schluter part has failed, there are a few checks any owner can do safely: feel for soft spots in the tile, look for cracks running in a straight line, and note whether the damp smell follows rain. What you should not do is cut into the tile or remove the drain to find the leak. Schluter waterproofing is a system, and once you open it, you’ve broken the seal that was keeping the water where it belonged. Without the right membrane, thinset, and seam sequence, the repair will leak again. If the leak is in a shower above a living space in Los Angeles, the water damage underneath can easily outweigh the Schluter repair by the time anyone sees it. Call us at (470) 298-9650 and we’ll diagnose it before you spend on demolition.

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