Walk-in shower planning guide
Planning a walk-in shower — what Puget Sound homeowners need to know.
A practical guide to curbless showers, waterproofing systems, tile selection, and aging-in-place design — from a WA L&I-licensed bathroom remodeler.
Everything you need to know before planning a walk-in or curbless shower in a Puget Sound home — covering waterproofing, drain types, tile, glass options, accessibility features, and the questions contractors rarely answer upfront. Written by a WA L&I-licensed Puget Sound general contractor.
Section 1 of 4
Planning basics
Size, layout, and what to decide before getting quotes.
How much space do I need for a curbless walk-in shower?
Minimum practical size is 36"×36" — workable but cramped. For comfortable daily use, 36"×48" is a significant improvement. For aging-in-place with a bench, 36"×60" or larger. For wheelchair transfer space, ADA guidelines require a minimum 60"×30" interior with 36" of clear maneuvering space at the entry. We measure your bathroom on-site and give you an honest assessment of what's possible in your actual footprint.
What is the difference between a linear drain and a center drain for curbless showers?
A center drain requires the shower floor to slope toward the center from all four sides — a complex slope that becomes difficult to achieve cleanly with large-format tile. A linear drain (long channel at one end of the shower) requires the floor to slope in one direction only — simpler, more compatible with large-format tile, and cleaner in appearance. Linear drains cost more and require precise installation of the slope, but are the standard for large-format tile curbless showers. For smaller tile (4"×4" or mosaic), a center drain works well.
Can I convert my existing shower to a curbless walk-in?
Usually yes, but it requires full demo and rebuild — not a cosmetic update. Converting to curbless requires: removing the existing shower pan and subfloor to the joists; evaluating subfloor condition (often the first time we see what moisture has done over the years); repositioning or replacing the drain; building a sloped mud bed or installing a prefabricated shower tray; installing a full waterproofing membrane; then tiling. Budget for subfloor repair as a contingency — it's common.
What frameless glass options are available for walk-in showers?
Common configurations: fully frameless (no frame or track, glass panels held by point-mounted hardware — the cleanest look); semi-frameless (framed sides with frameless door — less expensive than fully frameless); walk-in wet room (no door at all — open entry on one or two sides, requiring careful layout to prevent water from reaching the bathroom floor). Glass thickness: 3/8" is standard for frameless doors; 1/2" is premium and noticeably heavier. Finish options match your fixture finishes — brushed brass, matte black, brushed nickel, chrome.
Section 2 of 4
Waterproofing systems
The most important part of any shower build.
What waterproofing membrane systems are best for Pacific Northwest showers?
Schluter Kerdi, Wedi, and RedGard are the most commonly specified bonded membrane systems for shower applications in the Puget Sound. All three create a true waterproofing barrier at the tile-setting layer and are code-acceptable in Washington jurisdictions. Schluter Kerdi is the most widely used and the system our team typically specifies — it integrates with Schluter's drain systems and kerdi-board substrate for a fully bonded assembly. The important thing is using a bonded system, not felt paper.
What permits are required for a walk-in shower in Washington?
A walk-in shower installation that involves plumbing changes (drain relocation, valve rough-in, new supply lines) requires a plumbing permit from your local building department. If the project involves electrical work (new circuit, GFCI protection, heated floor), an electrical permit is required. We pull both in-house — they're built into your written proposal and timeline.
How long should a properly waterproofed shower last?
A shower built with a bonded membrane waterproofing system and quality porcelain tile should last 20–30 years with basic maintenance — re-caulking at grout-to-fixture transitions every 5–7 years. The limiting factor is almost always grout line maintenance (sealing porous grout annually) or caulk at movement joints failing and being ignored. A shower built with the old felt paper method in a Pacific Northwest climate typically shows waterproofing failure within 8–15 years.
Section 3 of 4
Tile & glass selection
What performs and what just looks good in the showroom.
What tile format works best for curbless shower floors?
For curbless shower floors that slope toward a linear drain: large-format porcelain (24"×24" or larger) with minimal cuts is the cleanest look. For a center-drain floor with multiple slopes: smaller mosaic or 4"×4" tile allows the installer to cut around the slope changes more precisely. All shower floor tile must meet wet COF ≥ 0.42 — most textured porcelain tiles qualify. Polished or smooth tile is not appropriate for shower floors regardless of how it looks.
Can I use natural stone in a walk-in shower?
Yes, but with important caveats for a Pacific Northwest climate. Natural stone (marble, travertine, slate) is porous and requires annual sealing to resist moisture absorption. In a shower that gets daily use, sealing has to be maintained consistently — something many homeowners let slip. Unsaled or undersealed natural stone in a shower will stain, etch, and eventually degrade the grout and substrate. Porcelain tile that replicates the look of marble or travertine delivers a similar aesthetic with essentially zero maintenance.
How do I choose between a shower curtain and frameless glass for a walk-in shower?
For a curbless walk-in shower: frameless glass is the standard for a reason — it keeps water in the shower zone without a curb to physically contain it, and it's much easier to clean than a shower curtain that traps moisture. A curtain on a curbless shower requires careful layout (typically an L-shaped or U-shaped curtain rod configuration) and can still allow splash onto the bathroom floor. If budget is a constraint, a semi-frameless glass panel (fixed glass with a simple door) is a significant step up from a curtain at a lower cost than full frameless.
Section 4 of 4
Aging-in-place & accessibility
Building for the long term costs almost nothing extra when done at the right time.
What aging-in-place features should I build into my walk-in shower now?
Features that cost almost nothing to add during the build and are expensive to retrofit: (1) Grab bar blocking — solid blocking in walls at 33–36" height around the shower entry and seat area. (2) Fold-down bench or built-in bench seat in the shower — requires planning during the waterproofing phase. (3) Curbless threshold — already standard in a well-designed walk-in shower. (4) Handheld showerhead on a height-adjustable bar — a plumbing rough-in decision, not expensive. (5) Wider shower entry (36"+ clear) — a design decision made at planning, not construction.
What is the right height for a shower bench?
A built-in shower bench seat height of 17–19 inches from the finished floor is the ADA-recommended range for comfortable transfer from a seated position. For a household without current mobility concerns, 18" is the standard. The bench should have a depth of 15–16" for comfortable seating. Bench waterproofing is as important as floor and wall waterproofing — a bench top that isn't properly sloped and waterproofed will collect water and fail.
Do I need to add grab bars now, or can I add them later?
You can add grab bars later — but only safely if blocking was installed in the walls during the build. Without blocking, grab bars can only be anchored to studs, and the studs may not fall in the locations that work best for your use pattern. Blocking costs $200–$400 to add during a remodel. Adding blocking later requires cutting out tile, opening the wall, installing the blocking, patching, and re-tiling — a $1,500–$3,000+ job. Add the blocking now, even if you don't plan to install grab bars for years.
Ready to talk about your project?
Free on-site consultation, written proposal at the end. Call 1-888-484-3132 or book online.