HOW TO CHOOSE A SHOWER BASE OR TILE-OVER TRAY
Updated June 2026. A plain-English guide for Australian homeowners, renovators, tilers, plumbers and builders.
Contents:
• Two categories, not one
• Shower bases: Polymarble & SMC
• Tile-over trays: BMC & XPS
• Side-by-side comparison
• Which one should I pick?
• Installation notes
• Warranty
• FAQs
• Next steps
Polymore sells two different products in the bathroom floor space:
• Shower bases (pre-finished) — Polymarble and SMC. You stand directly on the base.
• Tile-over trays (not pre-finished) — AP Tile Tray (BMC plastic) and XPS (foam). Tiles go on top, the tray is hidden.
Get the category right first. The website navigation reflects this: BASE has POLY and SMC; XPS and TILE TRAY are separate.
High-strength cast marble with a gloss gelcoat finish — the traditional Australian shower base, used for decades. Solid, cool to the touch, can be repaired if chipped.
Two versions: Original (60mm, 17mm tile flange) and Slim-Line (40mm).
Sizes: 820×820, 900×900, 1000×1000, 1200×900 + corner bases. Fits alcove (between three walls) — common Australian layout. White as standard, Ivory on request.
Warranty: 1 year.
Best for: family bathrooms where the traditional stone-look is the priority.
Pros: classic gloss gelcoat, hard-wearing, repairable, integrated 50mm waste, standard 73mm step height fits a standard screen.
Cons: needs a mortar bed, only 1-year warranty, heavier than SMC or XPS.
See Polymarble bases · install guide · spec sheet.
SMC = Sheet Moulding Compound, a fibre-reinforced thermoset plastic moulded in one piece. Dense, rigid, self-supporting (no mortar bed).
Two ranges:
• GT Slate (15-year) — slate finish, 26mm or 40mm, sizes up to 2000×900. The premium choice.
• GT Gloss (5-year) — gloss gelcoat, 40mm, 900×900 and 1200×900. The original SMC range.
Both: self-supporting, built-in fall, 50mm waste supplied, white or black (slate), centre or offset drain. See the GT spec sheet for the full model list (GT-CC, GT-DECO, GT-SLT, GT-SLTN, GT, GT-T, GT-CO, GT-CNR, GT-COSLT).
Best for: GT Slate — premium renovations, designers, builders wanting the longest warranty. GT Gloss — rentals, investment properties, projects where gloss look and 5-year warranty is acceptable.
Pros: self-supporting, repairable, fast install, slate series includes 2 aluminium flashings.
Cons: heavier than XPS, 5-year warranty on gloss range (read the spec).
See SMC bases · install guide · slate install guide.
BMC (Bulk Moulding Compound) is a fibre-reinforced thermoset plastic moulded into a rigid tray with a factory-formed fall. Installed in the floor, tiled over — the finished shower looks seamless with no visible tray edge.
Sizes: 895×895, 995×995, 1195×895. Four waste variants (rear centre, centre, rear long stainless grate, centre stainless grate).
Warranty: 5 years (per install guide — confirm with Polymore at order).
Best for: high-end bathrooms and apartments wanting a seamless level-floor shower.
Pros: invisible (fully tiled), cuttable on site, factory-formed fall, works with underfloor heating.
Cons: must be tiled by an experienced tiler, leaks are catastrophic if waterproofing fails, total install cost higher than a pre-finished base.
See AP Tile Trays · install guide · approved adhesive list.
A tile-over tray, not a shower base — installed in the floor, then tiled over (same category as the AP Tile Tray above).
High-density XPS foam core with a fibreglass-reinforced cement-polymer coating on both faces. Pre-sloped to drain. Polymore's marketing name is SAFE TRAY (the install PDF is titled "SAFE TRAY — NO MORE SCREED").
Structure: 25mm thick at the edges, 8mm at the drain recess (centre-waste models) or 10mm (offset-waste models). 110mm drain hole, 200mm recess. Foam is 100% waterproof.
Sizes (10): Centre-waste — 900×900, 1200×1200, 1500×1000, 2000×1000, 1200×900. Offset-waste (drain 200mm from long edge) — 1200×900, 1500×1000, 2000×1000, 900×1500, 1500×900.
Warranty: not published on the spec sheets — confirm with Polymore at order time.
Best for: apartments and upper floors (lightest of the four), retrofit jobs with tight access, showers where you want a warm-feeling floor (XPS is a thermal insulator).
Pros: lightest, warm underfoot, pre-sloped, pre-formed drain recess, cuttable on site, supports 100mm tiles without compression, replaces traditional screeding.
Cons: no published warranty, thinner than SMC/polymarble (protect the drain recess during install), 10 sizes with 2 drain configs — always check the spec PDF, less common in Australia so your tiler may be less familiar.
See XPS trays · SAFE TRAY install procedure.
• Owner-occupier, family bathroom, traditional look: Polymarble Original 60mm.
• Want a low-profile base: Polymarble Slim-Line 40mm or SMC slate 26mm.
• Builder doing 3–10 apartments/units a year: SMC slate — best balance of cost, install speed, 15-year warranty.
• Apartment above another unit (weight matters): XPS or SMC slate — both light and self-supporting.
• Investment property or rental: SMC slate — durable, 15-year warranty, low callbacks.
• Seamless level-floor shower: AP Tile Tray — tiler tiles directly over the tray.
• Designer home, large walk-in (1500–2000mm): SMC slate 1800×900 or 2000×900, or XPS 2000×1000.
Three rules apply regardless of base type:
1. Waterproofing is mandatory (AS 3740) — not optional. Your tiler or plumber handles this.
2. Licensed plumber for the drain connection — required to keep warranty valid and meet state regs.
3. Built-in fall — every base we sell has factory-formed fall to the drain, so you don't slope the floor yourself.
Per-type notes:
• Polymarble: full mortar bed required. Don't install on uneven subfloor.
• SMC slate: self-supporting, no mortar. Screw the 2 supplied aluminium flashings to the base (1 screw per 150mm, 20mm from ends) with sealant between.
• AP Tile Tray: direct to joist (max 450mm centres), on a mortar bed, or silicone-glued. Use epoxy adhesive for tiles.
• XPS: follow the SAFE TRAY install procedure — joists, structural board, 10×60mm flashing, 40×40mm angle, polyurethane adhesive.
• Polymarble — 1 year
• SMC slate — 15 years
• SMC gloss — 5 years
• AP Tile Tray — 5 years (per install guide)
• XPS — confirm at order
• Shower screens (glass excluded) — 5 years
• Acrylic liners, freestanding baths, sinks — 2 years
• Glass components — not warrantable (industry-wide)
Voids the warranty: non-licensed plumber for drain, no waterproofing, misuse/abuse, non-slip suction mats left on the base, improper storage, unauthorised modification.
Keep on file: proof of purchase, plumber's licence number, and get pre-authorisation from Polymore before returning anything. Warranty covers product only — you cover labour.
See full warranty terms.
The drain connection must be done by a licensed plumber under Australian regulations — this is also a warranty condition. Tiling and waterproofing (for tile-over trays) should be done by a qualified tiler.
Most common: 900×900, 1000×1000, 1200×900. Allow at least 600mm of floor space outside the shower for drying off, and check the doorway + stair access for upper floors.
Almost always yes. See shower screens for framed and semi-frameless options. Note: glass is not covered by the Polymore warranty (industry-wide).
Warm water, mild detergent, soft cloth. Avoid abrasives, bleach, acetone — they dull gelcoat or damage slate. Do not leave non-slip suction mats on the base — trapped moisture damages gelcoat and is explicitly excluded from warranty.
Most bases ship from our Melbourne warehouse within 1–2 business days, Australia-wide. Trade customers get priority stock — apply for a trade account.
Browse bathroom products, or if you're a builder, tiler, plumber or renovator doing multiple jobs a year, apply for a Polymore trade account — trade pricing, priority stock allocation, and dedicated support.
Updated June 2026. A plain-English guide for Australian homeowners, renovators, tilers, plumbers and builders.
Contents:
• Two categories, not one
• Shower bases: Polymarble & SMC
• Tile-over trays: BMC & XPS
• Side-by-side comparison
• Which one should I pick?
• Installation notes
• Warranty
• FAQs
• Next steps
Two categories, not one — what to know first
Polymore sells two different products in the bathroom floor space:
• Shower bases (pre-finished) — Polymarble and SMC. You stand directly on the base.
• Tile-over trays (not pre-finished) — AP Tile Tray (BMC plastic) and XPS (foam). Tiles go on top, the tray is hidden.
Get the category right first. The website navigation reflects this: BASE has POLY and SMC; XPS and TILE TRAY are separate.
Shower bases (pre-finished)
1. Polymarble shower bases (cast marble)
High-strength cast marble with a gloss gelcoat finish — the traditional Australian shower base, used for decades. Solid, cool to the touch, can be repaired if chipped.
Two versions: Original (60mm, 17mm tile flange) and Slim-Line (40mm).
Sizes: 820×820, 900×900, 1000×1000, 1200×900 + corner bases. Fits alcove (between three walls) — common Australian layout. White as standard, Ivory on request.
Warranty: 1 year.
Best for: family bathrooms where the traditional stone-look is the priority.
Pros: classic gloss gelcoat, hard-wearing, repairable, integrated 50mm waste, standard 73mm step height fits a standard screen.
Cons: needs a mortar bed, only 1-year warranty, heavier than SMC or XPS.
See Polymarble bases · install guide · spec sheet.
2. SMC shower bases (gloss & slate)
SMC = Sheet Moulding Compound, a fibre-reinforced thermoset plastic moulded in one piece. Dense, rigid, self-supporting (no mortar bed).
Two ranges:
• GT Slate (15-year) — slate finish, 26mm or 40mm, sizes up to 2000×900. The premium choice.
• GT Gloss (5-year) — gloss gelcoat, 40mm, 900×900 and 1200×900. The original SMC range.
Both: self-supporting, built-in fall, 50mm waste supplied, white or black (slate), centre or offset drain. See the GT spec sheet for the full model list (GT-CC, GT-DECO, GT-SLT, GT-SLTN, GT, GT-T, GT-CO, GT-CNR, GT-COSLT).
Best for: GT Slate — premium renovations, designers, builders wanting the longest warranty. GT Gloss — rentals, investment properties, projects where gloss look and 5-year warranty is acceptable.
Pros: self-supporting, repairable, fast install, slate series includes 2 aluminium flashings.
Cons: heavier than XPS, 5-year warranty on gloss range (read the spec).
See SMC bases · install guide · slate install guide.
Tile-over trays (under-tile)
3. AP Tile Trays (BMC, 60mm)
BMC (Bulk Moulding Compound) is a fibre-reinforced thermoset plastic moulded into a rigid tray with a factory-formed fall. Installed in the floor, tiled over — the finished shower looks seamless with no visible tray edge.
Sizes: 895×895, 995×995, 1195×895. Four waste variants (rear centre, centre, rear long stainless grate, centre stainless grate).
Warranty: 5 years (per install guide — confirm with Polymore at order).
Best for: high-end bathrooms and apartments wanting a seamless level-floor shower.
Pros: invisible (fully tiled), cuttable on site, factory-formed fall, works with underfloor heating.
Cons: must be tiled by an experienced tiler, leaks are catastrophic if waterproofing fails, total install cost higher than a pre-finished base.
See AP Tile Trays · install guide · approved adhesive list.
4. XPS tile-over trays (SAFE TRAY, 25mm)
A tile-over tray, not a shower base — installed in the floor, then tiled over (same category as the AP Tile Tray above).
High-density XPS foam core with a fibreglass-reinforced cement-polymer coating on both faces. Pre-sloped to drain. Polymore's marketing name is SAFE TRAY (the install PDF is titled "SAFE TRAY — NO MORE SCREED").
Structure: 25mm thick at the edges, 8mm at the drain recess (centre-waste models) or 10mm (offset-waste models). 110mm drain hole, 200mm recess. Foam is 100% waterproof.
Sizes (10): Centre-waste — 900×900, 1200×1200, 1500×1000, 2000×1000, 1200×900. Offset-waste (drain 200mm from long edge) — 1200×900, 1500×1000, 2000×1000, 900×1500, 1500×900.
Warranty: not published on the spec sheets — confirm with Polymore at order time.
Best for: apartments and upper floors (lightest of the four), retrofit jobs with tight access, showers where you want a warm-feeling floor (XPS is a thermal insulator).
Pros: lightest, warm underfoot, pre-sloped, pre-formed drain recess, cuttable on site, supports 100mm tiles without compression, replaces traditional screeding.
Cons: no published warranty, thinner than SMC/polymarble (protect the drain recess during install), 10 sizes with 2 drain configs — always check the spec PDF, less common in Australia so your tiler may be less familiar.
See XPS trays · SAFE TRAY install procedure.
Side-by-side comparison
| Type | Thickness | Standard sizes | Colours | Mortar bed? | Warranty |
|---|---|---|---|---|---|
| Polymarble (Original 60mm / Slimline 40mm) | 40 or 60 mm | 820×820 to 1200×900 + corner | White, Ivory (on request) | Yes — required | 1 year |
| SMC slate (15-yr) | 26 or 40 mm | 1000×900 to 2000×900 | White, Black | No — self-supporting | 15 years |
| SMC gloss (5-yr) | 40 mm | 900×900, 1200×900 | White | No — self-supporting | 5 years |
| AP Tile Tray (BMC) (under-tile) | 60 mm | 895×895 to 1195×895 | Tiled over (any) | Optional | 5 years (per install guide) |
| XPS (SAFE TRAY) | 25 mm edge / 8–10 mm drain | 900×900 to 2000×1000 | Tiled over (any) | No | Confirm at order |
Which one should I pick?
• Owner-occupier, family bathroom, traditional look: Polymarble Original 60mm.
• Want a low-profile base: Polymarble Slim-Line 40mm or SMC slate 26mm.
• Builder doing 3–10 apartments/units a year: SMC slate — best balance of cost, install speed, 15-year warranty.
• Apartment above another unit (weight matters): XPS or SMC slate — both light and self-supporting.
• Investment property or rental: SMC slate — durable, 15-year warranty, low callbacks.
• Seamless level-floor shower: AP Tile Tray — tiler tiles directly over the tray.
• Designer home, large walk-in (1500–2000mm): SMC slate 1800×900 or 2000×900, or XPS 2000×1000.
Installation notes for Australia
Three rules apply regardless of base type:
1. Waterproofing is mandatory (AS 3740) — not optional. Your tiler or plumber handles this.
2. Licensed plumber for the drain connection — required to keep warranty valid and meet state regs.
3. Built-in fall — every base we sell has factory-formed fall to the drain, so you don't slope the floor yourself.
Per-type notes:
• Polymarble: full mortar bed required. Don't install on uneven subfloor.
• SMC slate: self-supporting, no mortar. Screw the 2 supplied aluminium flashings to the base (1 screw per 150mm, 20mm from ends) with sealant between.
• AP Tile Tray: direct to joist (max 450mm centres), on a mortar bed, or silicone-glued. Use epoxy adhesive for tiles.
• XPS: follow the SAFE TRAY install procedure — joists, structural board, 10×60mm flashing, 40×40mm angle, polyurethane adhesive.
Warranty in Australia
• Polymarble — 1 year
• SMC slate — 15 years
• SMC gloss — 5 years
• AP Tile Tray — 5 years (per install guide)
• XPS — confirm at order
• Shower screens (glass excluded) — 5 years
• Acrylic liners, freestanding baths, sinks — 2 years
• Glass components — not warrantable (industry-wide)
Voids the warranty: non-licensed plumber for drain, no waterproofing, misuse/abuse, non-slip suction mats left on the base, improper storage, unauthorised modification.
Keep on file: proof of purchase, plumber's licence number, and get pre-authorisation from Polymore before returning anything. Warranty covers product only — you cover labour.
See full warranty terms.
Frequently asked questions
Can I install it myself?
The drain connection must be done by a licensed plumber under Australian regulations — this is also a warranty condition. Tiling and waterproofing (for tile-over trays) should be done by a qualified tiler.
What size do I need?
Most common: 900×900, 1000×1000, 1200×900. Allow at least 600mm of floor space outside the shower for drying off, and check the doorway + stair access for upper floors.
Do I need a shower screen too?
Almost always yes. See shower screens for framed and semi-frameless options. Note: glass is not covered by the Polymore warranty (industry-wide).
How do I clean it?
Warm water, mild detergent, soft cloth. Avoid abrasives, bleach, acetone — they dull gelcoat or damage slate. Do not leave non-slip suction mats on the base — trapped moisture damages gelcoat and is explicitly excluded from warranty.
How long does delivery take?
Most bases ship from our Melbourne warehouse within 1–2 business days, Australia-wide. Trade customers get priority stock — apply for a trade account.
Next steps
Browse bathroom products, or if you're a builder, tiler, plumber or renovator doing multiple jobs a year, apply for a Polymore trade account — trade pricing, priority stock allocation, and dedicated support.
Still not sure which base to pick?
Tell us your bathroom size, tile choice, and budget — we'll recommend the right base in 2 minutes.
This guide is general information only. For specific installation requirements, always consult a licensed plumber or builder. Polymore shower bases are imported and selected to Australian specifications; see warranty and about us for details. Specifications (thickness, sizes, colours, warranty periods) are correct as of June 2026 and may change — always check the product page or spec sheet for the most current information before ordering.