Tub-to-Shower Conversion Materials Guide
Every material decision for a successful tub-to-shower conversion — tile, waterproofing, shower pans, glass enclosures, fixtures, drains, and conversion-specific substrates — with pricing, durability ratings, and hard water recommendations for Boise and Treasure Valley homes.
Tile is the largest visual element in your new shower and typically represents 30–40% of the total project cost. In a tub-to-shower conversion, tile selection is especially important because the entire shower surface — walls, floor, curb, and niche — is built from scratch. There is no existing tile to match or work around. This gives you complete design freedom but also means every tile decision matters. Here is an honest comparison of the four most popular tile categories we install in Boise-area tub-to-shower conversions, with specific notes on how each performs against Treasure Valley's hard water at 10–14 grains per gallon.
Large-Format Porcelain
Most Popular for Conversions
$4 – $12 / sq ft (material)
Pros
- Water absorption under 0.5%
- Fewer grout lines — less hard water buildup
- Realistic stone and marble looks without sealing
- Extremely durable and stain-resistant
Cons
- Heavier — requires solid cement board substrate
- Higher labor cost for precision cutting
- Not suitable for shower floors (too large for slope)
Boise conversion note: Large-format porcelain (12×24, 24×48) is our number-one recommendation for conversion shower walls. The standard 60″ × 30″ tub alcove is an ideal canvas for large-format tile — three walls with clean, modern lines and minimal grout joints. In Boise's hard water environment, the dramatically reduced grout count means far less surface area for mineral deposits to accumulate and discolor.
Ceramic Tile (Subway & Field)
$1 – $6 / sq ft (material)
Pros
- Lowest material cost
- Huge variety of colors, shapes, and patterns
- Easy to cut and install
- Widely stocked at Boise tile retailers
Cons
- Higher water absorption (3–7%)
- More grout lines with smaller formats
- More porous — stains easier in hard water
- Not recommended for shower floors
Boise conversion note: Ceramic subway tile (3×6 and 4×12) is a popular budget-friendly choice for conversion shower walls. It works well on walls where water exposure is intermittent. For budget-minded conversions in Nampa, Kuna, and West Boise, ceramic walls paired with a porcelain mosaic floor provides the best value balance. Pair with epoxy grout to offset ceramic's higher porosity in Boise's hard water.
Natural Stone (Marble, Travertine)
$10 – $30 / sq ft (material)
Pros
- Unmatched natural beauty and uniqueness
- Premium, luxury aesthetic
- Adds significant home value
Cons
- Requires professional sealing every 6–12 months
- Absorbs minerals from Boise hard water
- Highest material and labor cost
- Etches from acidic cleaners
Boise conversion note: We love natural stone as an accent — a feature wall, niche liner, or bench cap — rather than full-shower coverage. Boise's 10–14 gpg hard water will stain and etch unsealed stone within months. If you choose marble for a full conversion, commit to quarterly sealing and a water softener. Honed finishes show water spots less than polished. Popular in Eagle and SE Boise luxury conversions.
Glass Mosaic Tile
$8 – $25 / sq ft (material)
Pros
- Zero water absorption — completely non-porous
- Brilliant color and light-reflective depth
- Ideal for accents, niches, and feature strips
Cons
- Many grout lines (more maintenance)
- Higher labor cost for installation
- Can chip if impacted
- Requires unsanded or epoxy grout
Boise conversion note: Glass mosaic is excellent for accent bands, shower niche interiors, and feature walls in converted showers. The glass itself is immune to hard water damage, but the heavy grout-line count means more surface area for mineral buildup. Use epoxy grout with glass mosaic in Boise to eliminate the grout maintenance issue entirely. Glass mosaic on shower floors provides excellent slip resistance due to the many grout joints.
Most Boise tub-to-shower conversions use a combination approach: large-format porcelain on the walls for a modern, low-maintenance surface, small-format porcelain mosaic on the shower floor for slope conformity and slip resistance, and a glass mosaic or natural stone accent in the niche or as a feature strip. This strategy balances aesthetics, durability, and budget while minimizing hard water maintenance in Boise's mineral-heavy water supply.
Waterproofing is the single most critical material decision in any tub-to-shower conversion. Unlike a standard shower remodel where the existing waterproofing may still be functional, a conversion requires building the entire waterproofing system from scratch. The bathtub was a self-contained, watertight unit — once it is removed, the floor structure, drain location, and wall substrates all change. Every surface that will be tiled must be waterproofed before the first tile is set. Water intrusion behind tile causes mold, rot, and structural damage that costs far more to repair than proper waterproofing costs upfront.
Schluter Kerdi System
Our Recommended System
$300 – $600 (materials for typical conversion)
How It Works
Polyethylene sheet membrane bonded to cement board with unmodified thin-set mortar. The Kerdi membrane creates a continuous waterproof barrier that also serves as an uncoupling layer, preventing tile cracking from substrate movement. The system includes pre-formed inside and outside corners (Kerdi-Kereck), pipe collars (Kerdi-Seal), and a bonding flange drain (Kerdi-Drain) that integrates directly with the membrane.
Why It Wins for Conversions
The Kerdi system is purpose-built for tile showers. In a tub-to-shower conversion, where the floor, walls, and drain are all being rebuilt, having a single manufacturer's integrated system eliminates compatibility questions between components. The pre-sloped Kerdi-Shower-ST tray removes the need for a custom mud bed, reducing installation time and eliminating slope errors. Schluter provides a system warranty when all components are used together.
Liquid-Applied Membranes
$100 – $250 (materials for typical conversion)
How It Works
Products like Custom Building Products RedGard, Laticrete Hydroban, and Mapei AquaDefense are roller-applied liquid coatings that cure into a flexible, waterproof membrane. Applied in two full coats over cement board, with reinforcing fabric tape at all seams, corners, and penetrations. Must achieve a minimum dry film thickness (typically 30 mils) to be effective.
Considerations for Conversions
Liquid membranes are effective when applied correctly, but they are installer-dependent — proper thickness, full coverage, and reinforced seams are critical. In a conversion where the subfloor has been modified and new cement board installed, liquid membranes require careful attention at the many new joints and transitions. Best suited for wall waterproofing when paired with a Kerdi or pre-formed shower pan on the floor.
Boise Winter Note
Liquid-applied membranes require a minimum 50°F ambient temperature during application and curing. During Boise winters (Nov–Feb), unheated bathrooms during renovation may not meet this threshold. Ensure the HVAC system is running or use temporary heat to maintain proper curing conditions.
Pre-Formed Shower Pans
$200 – $500 (pan assembly only)
How It Works
Pre-formed foam or plastic shower pans (Schluter Kerdi-Shower-ST, Wedi Fundo Primo, Noble FreeForm) come factory-sloped with integrated drain openings. They install directly over the plywood subfloor and provide both the shower base and the waterproof barrier in one component. Tile is set directly on the pan surface.
Why They Excel in Conversions
Pre-formed pans are ideal for tub-to-shower conversions because they eliminate the most error-prone step: creating a properly sloped mortar bed. When a tub is removed, the subfloor beneath is rarely level or in perfect condition. A pre-formed pan bridges minor subfloor imperfections and guarantees consistent 1/4-inch-per-foot slope to the drain. This reduces both installation time and the risk of ponding water.
Sizing for Tub Alcoves
Most Boise tub alcoves measure 60″ × 30″ or 60″ × 32″. Schluter and Wedi both offer pre-formed pans in these exact dimensions, making them a drop-in solution for standard alcove conversions.
Iron Crest's Waterproofing Standard
Every tub-to-shower conversion we build in Boise uses a complete Schluter Kerdi system on the shower floor (Kerdi-Shower-ST pan or Kerdi-Line linear drain tray) with Kerdi membrane on all walls to a minimum height of 6 feet above the finished floor. All corners receive pre-formed Kerdi-Kereck corners, all pipe penetrations receive Kerdi-Seal collars, and the pan-to-wall transition is sealed with Kerdi-Band. This system has a zero failure rate across our conversion projects. We do not cut corners on waterproofing — the consequences of failure are too costly and too difficult to repair after tile is installed.
The glass enclosure defines the look and feel of your converted shower. In a tub-to-shower conversion, you are replacing a shower curtain rod and curtain (or a sliding glass tub door) with a purpose-built glass enclosure designed for a walk-in shower. The enclosure type affects the shower's visual openness, ease of cleaning, water containment, and long-term maintenance — especially in Boise where hard water at 10–14 gpg creates mineral deposits on untreated glass.
Frameless Glass
Most Popular Upgrade
$1,500 – $5,000 installed
Uses 3/8-inch or 1/2-inch tempered glass panels secured with minimal hardware — stainless steel or brass clamps, hinges, and U-channels mounted to the wall and floor. No metal framing around the glass edges. The result is a clean, open look that makes the shower feel larger and lets the tile work take center stage.
Hard water advantage: No metal channels or frames where water and mineral deposits collect. The smooth, continuous glass surface is easier to squeegee and wipe than any framed option. We strongly recommend a factory-applied hydrophobic coating (EnduroShield or Diamon-Fusion) that causes water to sheet off instead of bead and dry in place.
Conversion fit: The standard 60″ tub alcove opening accommodates a frameless door + fixed panel configuration perfectly. A typical setup: 24″–30″ swinging door with a 30″–36″ fixed panel.
Semi-Frameless Glass
$800 – $2,000 installed
A metal frame runs along the top rail and door edges, but the fixed panel and bottom are frameless. Uses thinner glass (5/16-inch or 3/8-inch) because the frame provides structural support. A solid middle-ground between the clean look of frameless and the lower cost of framed enclosures.
Hard water consideration: The top rail and door frame create channels where water sits and minerals accumulate. These areas require regular cleaning with a toothbrush or detail brush to prevent buildup. Still significantly better than a fully framed enclosure for hard water maintenance.
Best for: Mid-range conversions in Meridian, Nampa, and Kuna where the homeowner wants an upgraded look without the full frameless investment.
Framed Glass Enclosure
$400 – $1,200 installed
A continuous metal frame surrounds all glass panels and the door. Uses the thinnest glass (1/4-inch) because the frame provides all structural support. The most affordable option and widely available in standard sizes at home improvement stores.
Hard water warning: Framed enclosures are the hardest to maintain in Boise's hard water. Every frame channel, bottom track, and rubber seal traps water and accumulates mineral deposits. The bottom track in particular becomes a maintenance headache — hard water residue builds up inside the track and is nearly impossible to clean without removing the doors.
Our recommendation: If budget is tight, we suggest a fixed glass panel (no door, no frame) on a curbed conversion instead of a full framed enclosure. A single fixed panel costs $400–$800 installed and has zero channels for mineral buildup.
Glass Coating Recommendations for Boise
Regardless of frame type, every glass enclosure in Boise should have a protective hydrophobic coating applied at installation. These nano-coatings create an invisible barrier that causes water to sheet off instead of bead and dry in place — preventing the mineral deposits that etch and cloud glass in our hard water environment.
EnduroShield
Professional-grade coating applied after installation. Lasts 3–5 years. $150–$300. Our go-to recommendation.
Diamon-Fusion
Chemical bond coating with lifetime warranty when professionally applied. $200–$400. Premium option.
ShowerGuard
Factory-applied ion beam coating permanently bonded to the glass during manufacturing. Must be specified at order. $200–$500 premium over standard glass.
A tub-to-shower conversion is one of the few times you get to choose your shower valve system from scratch. Unlike a shower remodel where you might keep the existing valve, a conversion involves relocating plumbing and installing new supply lines — which means new valve hardware is part of the project. This is your opportunity to upgrade from a basic pressure-balance valve to a thermostatic system, add a rain head, or include a handheld showerhead for accessibility and cleaning convenience.
Pressure-Balance Valve
Standard / Code Minimum
$150 – $400 (valve + trim)
Automatically adjusts water flow to maintain a consistent hot/cold ratio when pressure changes occur (e.g., when a toilet flushes or dishwasher starts). Required by Idaho plumbing code in all new shower installations, including conversions. Single-handle operation with volume and temperature on one control.
Recommended brands: Delta MultiChoice Universal ($150–$250 valve + trim) — allows future trim changes without opening the wall. Kohler Rite-Temp ($200–$350) — reliable and widely stocked by Boise plumbing suppliers. Moen M-PACT ($175–$300) — trim-interchangeable like Delta.
Best for: Budget and mid-range conversions. Single-outlet setups (one showerhead or one showerhead + handheld on a diverter).
Thermostatic Valve System
Premium Upgrade
$500 – $2,000+ (valve + trim)
Separates temperature control from volume control into independent handles. You set your preferred temperature once, and the thermostatic cartridge maintains it precisely — regardless of water pressure changes elsewhere in the home. Allows independent volume control for multiple outlets (rain head, handheld, body sprays).
Recommended brands: Hansgrohe iBox ($400–$800 rough-in + $300–$600 trim) — the industry standard for thermostatic performance. Grohe GrohTherm ($500–$1,000+) — precise SmartControl technology. Kohler Rite-Temp Thermostatic ($350–$700) — a more accessible entry into thermostatic control.
Best for: Premium conversions with rain head + handheld combos, multi-outlet systems, aging-in-place setups where precise temperature is a safety requirement, and homeowners who want spa-like control.
Rain Showerhead
8″–12″ overhead mount. Creates a drenching, spa-like experience. Ceiling-mount or wall-arm options. $100–$600.
Handheld Showerhead
Mounted on a slide bar or wall bracket. Essential for aging-in-place, pet washing, and shower cleaning. $75–$400.
Dual-Function Combo
Rain head + handheld on a diverter valve. The most popular fixture setup for conversions in Boise. $200–$800.
Grab Bars & Accessories
Decorative grab bars that double as towel bars. ADA-height installation. Soap niches and shelves. $50–$300 each.
Fixture Finish & Boise Hard Water
Fixture finish affects daily maintenance more than any other aesthetic choice in Boise's hard water environment. Brushed nickel is the most forgiving finish — its matte texture and warm tone mask mineral spots between cleanings. Champagne bronze(Delta) and brushed gold (Kohler) offer similar forgiveness with a warmer look. Matte black is the most popular finish in 2026 Boise bathroom design, but it is also the hardest to maintain — white calcium deposits are immediately visible and require wiping after every shower. Polished chrome falls in between: mineral spots are visible but easier to wipe off than matte finishes. Choose your finish based on your willingness to maintain it, not just aesthetics.
A tub-to-shower conversion requires several materials that a standard shower remodel does not. These are the structural and functional components that transform a bathtub alcove into a walk-in shower — the shower pan system, curb construction, drain assembly, and subfloor modifications that make the conversion possible. Understanding these materials helps you appreciate what is happening behind the finished tile and why proper conversion work costs more than simply retiling an existing shower.
Shower Pan Systems
Schluter Kerdi-Shower-ST (Pre-Sloped Foam Tray)
Factory-sloped expanded polystyrene tray with integrated Kerdi-Drain bonding flange. Available in 32″×60″ and 38″×60″ — perfect for standard tub alcoves. $250–$400 for the tray assembly.
Wedi Fundo Primo
Waterproof XPS foam pan with pre-sloped surface and integrated drain assembly. Lightweight, easy to cut for custom sizes. $300–$500 for the pan kit.
Mud-Set Mortar Bed (Traditional)
Deck mud (4:1 sand-to-cement) floated by hand to a 1/4″-per-foot slope over a PVC liner and pre-slope. Allows any drain location. Requires skilled installer. $200–$400 in materials but higher labor cost.
Curb Construction Materials
Schluter Kerdi-Board Curb (Pre-Formed)
Pre-formed waterproof foam curb that sits on the shower pan and is covered with Kerdi membrane. Available in 4.5″ height (standard code). No wood framing required. $50–$80 per curb.
Wood-Framed Curb (Traditional)
2×4 or 2×6 lumber stacked and screwed to the subfloor, then wrapped with cement board and waterproofing membrane. Allows custom heights. Must be fully waterproofed with no gaps. $20–$40 in lumber + membrane.
Curbless Transition (Zero-Threshold)
No curb at all — the bathroom floor transitions seamlessly into the shower. Requires recessing the shower pan below the bathroom floor level or building up the bathroom floor. Linear drain at the threshold is typical. Adds $500–$1,500 in subfloor modification costs.
Drain Assemblies
Center Point Drain
Traditional round drain with a bonding flange that integrates with the waterproofing membrane. The shower floor slopes from all four sides toward the center. $50–$150 for the drain assembly. Works with any shower pan system.
Linear (Trench) Drain
A channel drain that runs along one edge of the shower — typically the entry. Allows the floor to slope in a single direction, which works better with large-format floor tiles and is required for curbless designs. $300–$800 for the drain assembly. Brands: Schluter Kerdi-Line, Infinity Drain, QuickDrain.
Drain Relocation Requirements
The existing tub drain is almost always in a different location than where the shower drain needs to be. Relocating the drain requires cutting into the subfloor, modifying the P-trap, and sometimes rerouting the drainpipe. This is one reason conversions require a plumbing permit in Boise.
Subfloor & Substrate Materials
3/4″ Exterior-Grade Plywood
The subfloor under the tub is often thinner or damaged. We verify thickness and condition during demolition and replace as needed. Must be exterior-grade (CDX or better) for moisture resistance. $30–$50 per 4×8 sheet.
Cement Board (HardieBacker, Durock)
1/2″ cement board installed over wall studs as the tile substrate. Screwed every 8″ on center with cement board screws. All seams taped with alkali-resistant mesh tape. $10–$15 per 3×5 sheet.
Blocking for Grab Bars & Glass Hardware
2×6 or 2×8 blocking installed between wall studs at grab bar height (33″–36″) and glass clamp/hinge locations. This must be done before cement board goes up — it cannot be added after tile is installed. $20–$40 in lumber.
Boise's unique combination of hard water, housing stock characteristics, seasonal climate swings, and local supply chain availability creates specific challenges and opportunities for tub-to-shower conversion material selection. Understanding these local factors helps you make informed choices that perform well in the Treasure Valley environment for years after the conversion is complete.
Hard Water (10–14 GPG)
Boise's municipal water supply tests at 10–14 grains per gallon (gpg), classified as "hard" to "very hard" by USGS standards. Well water in surrounding Treasure Valley communities (Star, Middleton, Caldwell) can reach 20+ gpg. This mineral content directly impacts every material in your converted shower.
Material impacts for conversions: Porous cement grout discolors permanently within 2–3 years. Uncoated glass etches and clouds within months. Matte black fixtures show white mineral spots after every shower. Natural stone absorbs minerals and stains. Shower door tracks and frame channels accumulate hard, crusty mineral deposits that are nearly impossible to remove.
Mitigation strategy: A whole-home water softener ($1,500–$4,000 installed) is the single most effective protection. If a softener is not in the budget, prioritize epoxy grout, coated frameless glass, and brushed nickel fixtures — the three material choices that offer the most hard water resistance without a softener.
Housing Stock & Conversion Impacts
Boise's housing stock spans several distinct eras, and the age of your home directly impacts the materials needed for a successful tub-to-shower conversion.
Pre-1980 homes (North End, Bench, Vista): Cast iron or steel tubs are heavy (300–500 lbs) and require additional demolition labor. Galvanized steel drain lines must be replaced with ABS or PVC. Subfloors are often 5/8″ plywood or planking that needs replacement with 3/4″ exterior-grade plywood. Budget an extra $500–$1,500 for hidden structural issues.
1990s–2000s homes (SE Boise, W Boise, Meridian): Fiberglass tub/shower combos are lighter and easier to remove. Plumbing is typically copper or PEX. The 60″×30″ alcove is the ideal size for a walk-in shower. Main concern: greenboard drywall behind the tub surround must be replaced with cement board.
2010s+ homes (Eagle, Star, Kuna): Modern plumbing (PEX) and framing mean fewer surprises during demo. Subfloors are typically adequate. Main consideration is upgrading from a builder-grade pressure-balance valve to a thermostatic system.
Seasonal & Climate Factors
Boise's semi-arid climate with cold winters and hot summers creates specific conditions that affect material installation and performance in tub-to-shower conversions.
Winter installations (Nov–Feb): Indoor humidity drops to 15–25% when the furnace runs. This extreme dryness accelerates curing of cement-based thin-set and grout, which can cause cracking if not managed. Liquid waterproofing membranes require 50°F+ ambient temperature. Thin-set and grout must not freeze before curing. Schedule material deliveries to avoid freezing temperatures that damage uncured products.
Summer installations (Jun–Aug): Ideal conditions for all conversion materials. Moderate humidity and warm temperatures provide optimal curing. Longer daylight hours allow extended work windows. This is the busiest season for conversions in the Treasure Valley — book 4–6 weeks ahead.
Local Supplier Availability
Boise's growing population has expanded the local tile and fixture supply chain significantly. Most conversion materials are available locally with short lead times.
Tile: Floor & Decor (Meridian), Daltile (Boise), Arizona Tile (Boise), and Idaho Custom Tile carry extensive porcelain and ceramic inventory. Custom orders for specialty tile (handmade zellige, imported Italian porcelain) take 3–6 weeks. We recommend selecting tile early in the planning process.
Glass enclosures: Local glass fabricators (Boise Glass, Valley Glass, ABC Glass) can custom-measure and install frameless enclosures within 2–3 weeks of template. Standard sizes ship within 1–2 weeks from regional warehouses.
Schluter products: Stocked at local tile distributors and available same-day or next-day for standard components. Kerdi-Line linear drains in custom lengths may require 1–2 week special order.
The table below summarizes the cost ranges for every major material category in a Boise tub-to-shower conversion, broken down by budget tier. These are material-only costs — labor is additional and typically adds 50–100% to the material cost depending on complexity. A standard conversion uses a 60″×30″ tub alcove footprint, which requires approximately 80–110 square feet of wall tile and 12–15 square feet of floor tile.
| Material Category | Budget | Mid-Range | Premium |
|---|---|---|---|
| Wall Tile (per sq ft) | $1 – $4 | $5 – $12 | $15 – $30+ |
| Floor Tile (per sq ft) | $4 – $8 | $8 – $15 | $15 – $25+ |
| Shower Pan System | $150 – $250 | $250 – $450 | $400 – $800 |
| Waterproofing Membrane | $100 – $200 | $200 – $400 | $400 – $700 |
| Glass Enclosure (installed) | $400 – $800 | $1,000 – $2,500 | $2,500 – $5,000+ |
| Valve + Trim | $150 – $350 | $350 – $800 | $800 – $2,000+ |
| Showerhead(s) | $50 – $150 | $200 – $500 | $500 – $1,500+ |
| Drain Assembly | $50 – $100 | $100 – $300 | $300 – $800 |
| Curb Materials | $20 – $40 | $50 – $80 | $500 – $1,500* |
| Grout (epoxy recommended) | $30 – $60 | $60 – $120 | $80 – $150 |
| Glass Coating | — | $150 – $300 | $200 – $500 |
| Substrate & Blocking | $80 – $150 | $100 – $200 | $150 – $300 |
| Estimated Material Total | $1,500 – $3,500 | $3,500 – $7,500 | $7,500 – $16,000+ |
* Premium curb cost reflects curbless (zero-threshold) subfloor modifications. Prices reflect 2026 Boise-area market rates for materials only. Labor, demolition, plumbing modifications, and permits are additional. Contact us for a free personalized estimate based on your specific tub alcove dimensions, material selections, and conversion type.
What is the best tile for a tub-to-shower conversion in Boise?
What waterproofing system should be used for a tub-to-shower conversion?
Should I choose frameless or semi-frameless glass for my converted shower?
What shower pan system works best for a tub-to-shower conversion?
Do I need a linear drain or a center drain for my converted shower?
How does Boise hard water affect material choices for a tub-to-shower conversion?
Materials are one piece of the conversion puzzle. Explore our other tub-to-shower guides to plan your project from every angle — from costs and timelines to design ideas and permit requirements for Boise and the Treasure Valley.
Tub-to-Shower Conversion Service
Our full tub-to-shower conversion service overview
Conversion Cost Guide
Detailed pricing from $5,200 to $22,000+
Conversion Timeline
Phase-by-phase scheduling breakdown
Conversion Design Ideas
Styles, layouts, and trending features
Conversion Permits & Regulations
Boise & Ada County permit requirements
Shower Remodeling Service
Full shower remodeling for existing showers
Bathroom Tile & Waterproofing Systems
Deep dive on tile and waterproofing for all bathroom areas
Shower Remodel Materials Guide
Materials guide for standard shower remodels
Get a Free Estimate
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Our design team helps you select tile, waterproofing systems, glass enclosures, and fixtures that resist Boise’s hard water — all within your budget. Schedule a free in-home consultation to discuss your tub-to-shower conversion.