Custom Natural Stone & Marble Shower
The Mercer Island remodel where the homeowner has been saving toward a honed-Carrara shower since the build started. The Capitol Hill condo where a book-matched Calacatta back wall is the design centerpiece of the entire master bath. The downtown Bellevue penthouse where a travertine walk-in is the warm-stone counterpoint to the cold concrete the rest of the building reads in. The 1925 craftsman restoration where honed limestone reads as period-appropriate without the period maintenance demands of unfilled travertine. Natural stone — honed Carrara, Calacatta, Statuario, travertine, limestone — is the premium custom-shower material that turns a wet zone into the design moment of a remodel. The trade-off is specific and real — stone is porous, sensitive to acidic cleaners (citrus, vinegar, some commercial bathroom cleaners), demands white thinset to prevent dark mineral lines from bleeding through translucent marble, demands unsanded grout to prevent sand grains from scratching the polished or honed surface, and demands an annual re-seal cadence the homeowner has to commit to. Handis self-performs every step end to end — substrate prep, full Schluter KERDI sheet-membrane waterproofing, mortar-bed pan with the slope built in, slab selection at the yard with you for any book-match or vein-direction call, white-thinset setting, unsanded grout, and the Miracle 511 Impregnator or StoneTech Heavy-Duty Sealer two-coat seal. From $9,000 for a small honed-Carrara alcove up to $18,000 for a three-wall walk-in in book-matched Calacatta with a curbless pan and a frameless glass enclosure. The in-wall mixer rough-in on a from-scratch build subs to a licensed Washington L&I plumber.
Service
How a Custom Natural Stone Shower Build Works
Eight sequential steps from the slab-yard selection visit through the impregnator-seal final pass — the actual sequence Handis runs on every custom natural stone shower build.
Slab Yard Selection Visit
Meet at Pental Surfaces, Marble & Granite, or Walker Zanger showroom to walk the available slabs. Vein direction, mineral color, book-match potential, and slab consistency all chosen on site with the homeowner. Slab marked up in chalk for the cut diagram. Fabricator cuts to spec. The yard visit is standard scope on every natural-stone shower build.
Substrate Inspection and Demo to Stud
Existing shower demoed back to bare stud. Studs inspected for plumb and rot (sill plate especially). Subfloor inspected for soft spots. Any framing repair surfaced as a change-order before substrate goes up. Hidden rot from a previously leaking shower is documented before any new work proceeds.
Cement Board Substrate Over Studs
1/2-inch HardiBacker or Durock cement board screwed to studs and seam-thinset. Substrate set plumb and square. Panel seams staggered. Subfloor cement-boarded as well before the pan goes in. Substrate flatness checked with a 10-foot straightedge.
Mortar-Bed Pan Built and Sloped 1/4 Inch Per Foot
Sloped pre-pan in deck mud over a vapor-barrier layer. 40-mil PVC pan liner running 6 inches up the walls. Deck-mud topping with the slope built in to 1/4 inch per foot to the drain, verified with a 4-foot level in three directions. Cures 24 to 48 hours before the membrane goes over.
Schluter KERDI Sheet Membrane Bonded to Every Surface
Orange KERDI polypropylene-fleece sheet bonded with unmodified thinset and a 1/4-inch by 3/16-inch notched trowel to every cement-board wall and the pan topping. KERDI-BAND on every sheet seam and inside corner. KERDI-SEAL-PS at every penetration. KERDI-DRAIN at the drain. Curb wrapped on three sides. Membrane sits 24 hours.
Set Natural Stone in White Mapei Granirapid Thinset
White Mapei Granirapid or Ardex X4 thinset (NOT gray — gray bleeds dark mineral lines through translucent marble) on a notched trowel sized to the format. Back-butter every tile sized 12x12 and up. Tile beat to plane with a rubber float, joints kept tight (1/16 to 1/8 inch standard on stone). Cures 24 hours before grout.
Unsanded Grout, Color-Matched, No Sand Scratching
Unsanded grout (Mapei Keracolor U, Custom Polyblend Unsanded) — sand grains in sanded grout scratch polished and honed stone, so unsanded is the only correct choice. Color-matched to the stone tone. Floated into every joint at 45 degrees, struck in two damp-sponge passes, hazed off after set-up.
Miracle 511 Impregnator Sealer Applied in Two Coats
After grout cures 24 to 72 hours, two coats of Miracle 511 Impregnator (or StoneTech Heavy-Duty Sealer) wiped on with a clean cloth. Second coat after the first cures 24 hours. The impregnator penetrates the stone pore network and bonds inside the stone — does not coat the surface, does not change the look. Re-seal every 12 months on a heavy-use shower.
Custom Natural Stone & Marble Shower Pricing
Final pricing depends on the stone selected (Carrara honed is the entry; book-matched Calacatta and exotic stone is the premium), the shower footprint (alcove vs walk-in vs three-wall), the pan style (curbed standard or curbless), the niche and bench scope, and whether the in-wall mixer is being replaced (licensed-plumber sub). Stone is line-itemed separately from labor on every quote so you see the material cost clearly. Slab selection visit at the yard is included in the project scope. Request a free estimate for an accurate quote.
Tell us the shower footprint and the stone you have in mind — we will set up the slab-yard visit and quote the build with full KERDI waterproofing as standard.
Why Handis for Custom Natural Stone & Marble Showers
A natural stone shower is the install where two-thirds of the success or failure is invisible — the white thinset that does not bleed dark mineral lines through the translucent marble, the unsanded grout that does not scratch the honed surface during the strike pass, the impregnator sealer applied in two coats with the correct cure interval between coats. The most-common failed marble shower we are asked to re-do has gray thinset bleed-through visible behind the panels, sanded-grout scratch marks across the polished surface, and unsealed stone that took on staining within the first year. None of those failure modes are visible in the showroom — they show up six months after the install when the homeowner expected the shower to look the way the slab did at the yard. Handis uses the right materials end to end and we name every product on the quote. The stone you picked at the yard is the stone you see in the finished shower.
Estimate
Tell us the shower footprint (alcove, single-wall walk-in, two-wall walk-in, three-wall walk-in), the stone you have in mind (Carrara honed, Calacatta, Statuario, travertine, limestone), whether the design depends on book-matching or vein-direction (so we plan the yard visit), the niche and bench scope, the pan style (curbed or curbless), whether the in-wall mixer is staying or being replaced, and any known issues with the existing shower. We send a clear estimate with the slab-yard selection visit included, full KERDI waterproofing as standard, and the licensed-plumber portion named line by line on any new-mixer scope.
Customer Reviews
Recent custom natural stone and marble shower reviews from verified Handis customers.
Honed Carrara marble walk-in in our Mercer Island remodel. Handis met us at Pental to walk the slab yard for the right book-match. Used white Mapei Granirapid thinset so no mineral-line bleed through the translucent marble, unsanded grout, sealed with Miracle 511 Impregnator in two coats. The shower is the design centerpiece of the whole renovation. Twelve months in, no etching, no staining, the seal is still beading water.
Book-matched Calacatta on the back wall of our master walk-in. The vein pattern flows across the seam between the two panels — Handis marked the slab in chalk at Marble & Granite with us and the fabricator cut it perfectly. The contractor we'd used on the kitchen quoted the same job with gray thinset and we would never have known until the mineral lines bled through six months later. Handis walked us through the install protocol on the booking call.
Travertine walk-in in our downtown Bellevue penthouse. We wanted the warm-stone counterpoint to the cold concrete the rest of the building reads in. Handis used honed-and-filled travertine (avoided the unfilled-travertine maintenance burden we did not want), full KERDI waterproofing, sealed with StoneTech Heavy-Duty. The shower is the room we look forward to using every day now.
Honed limestone master shower in our 1925 craftsman restoration. The limestone reads period-appropriate without the maintenance burden of period unfilled materials. Handis explained the porosity differences (limestone absorbs more than Carrara, demands more sealer maintenance) on the booking call so we knew what we were committing to. We sealed it again at 11 months on their recommendation and the install looks like the day they finished.
Statuario marble three-wall walk-in with a built-in bench in our Capitol Hill condo. Premium stone, premium budget, and the install matched. Handis used white thinset throughout, brushed-brass Schluter trim that matches the shower mixer, unsanded grout in a custom-mixed warm-white to match the stone tone. The bench was framed and KERDI-wrapped, then seat-tiled in the same Statuario as the walls. Looks like a high-end European spa.
Frequently Asked Questions
Common questions about Handis custom natural stone and marble shower builds — material selection, waterproofing, sealer maintenance, slab-yard visits, and pricing.