The 48" × 48" KERDI-SHOWER-KIT builds a proper square shower — big enough to feel spacious, properly waterproofed from day one. Every component you need for a sealed, tiled shower in one kit, all warranted for 10 years by Schluter.

The center-drain tray is pre-sloped EPS foam — set it in thin-set, tile it the same day. No mortar bed. No waiting. The kit includes the shower curb, waterproofing membrane for the walls, all sealing strips and corner pieces, and pipe/valve seals. Drain grate kit ordered separately so you can choose the finish that matches your bathroom.

What's In the Box

• KERDI-SHOWER-T tray (48" × 48") — Pre-sloped EPS foam base, center drain, integrated KERDI waterproofing on surface
• KERDI-BOARD-SC shower curb — Pre-built waterproof foam curb, integrates with tray perimeter
• KERDI membrane — Sheet-applied waterproofing for shower walls, bonds into thin-set via fleece backing
• KERDI-BAND — Critical sealing strips for all joints, seams, and floor/wall transitions
• KERDI-KERECK formed corners — Pre-made inside/outside corners, no folding required
• KERDI-SEAL pipe and valve seals — Waterproofs penetrations at showerhead and mixing valve

The Case Against Traditional Waterproofing

Most shower failures aren't from bad tile — they're from bad waterproofing underneath. Cement board absorbs moisture (it's not waterproof — it just holds up when wet). Felt paper behind it is only as good as its laps and fastener holes. After a few years of hot showers, those systems fail invisibly, behind your tile. The KERDI system is bonded directly to the structure and sealed at every joint — water has nowhere to go except down the drain.

Installation Notes

• Bond the tray with Schluter ALL-SET (wood subfloor) or SET (concrete) — trowel the mortar and press the tray into full contact
• Use KERDI-BAND at every floor/wall junction — 2" overlap on each surface minimum
• Apply KERDI to walls with 1/8" × 1/8" square-notch trowel, overlap seams by 2"
• Tile goes directly over KERDI membrane — use SET, ALL-SET, or FAST-SET mortar
• Never grout changes of plane — use 100% silicone at corners and floor/wall transitions

Pro Tips

• Order an extra tube of KERDI-FIX. It's the adhesive sealant for pipe seals and any spot where you can't get full thin-set coverage. You'll always find one spot that needs it.
• The 48" × 48" square creates an almost-curbless look when paired with a zero-threshold door or frameless glass. If you want a fully curbless result, look at the KERDI-SHOWER-TT (thin-profile tray) instead.
• Mark your drain location on the subfloor before installing the tray. The center drain position on the tray must align with your rough-in — double-check measurements before setting.

Who Should Buy This

Homeowners building a standard square shower, contractors doing bathroom renovations where the client wants a proper warranty-backed waterproof system. The 48" × 48" is one of the most popular shower sizes — big enough for comfort, efficient on tile and glass door costs.

Also need: KERDI-DRAIN body (ABS or PVC, 2" or 3" outlet) + grate kit in your chosen finish, Schluter mortar, KERDI-BOARD panels for walls if starting from studs.