Tile Trims & Expansion Joints Buyer's Guide — TradieCart
Whether you're finishing a bathroom renovation, tiling a balcony, or laying large format floor tiles, the right trim and expansion joint makes all the difference. We stock Australia's widest range from Roberts Designs, Demtech, and BAT — covering aluminium, brass, stainless steel, and PVC profiles for every application.
Product Range
| Product | Best For |
|---|---|
| Roberts Aluminium L-Shape Trim | The go-to angle trim for most tiling jobs. 30+ colours including Maxisil colour-matched finishes, sizes from 4.5mm to 25mm. The widest range available in Australia. |
| Roberts Square Edge Trim | Clean, modern box profile for contemporary bathrooms and kitchens. Available in aluminium (7 finishes) and stainless steel Grade 304. |
| Roberts Brass L-Shape Trim | Premium decorative finish for feature walls and designer bathrooms. 8 sizes from 6mm to 22.5mm. |
| Roberts Stainless Steel L-Shape Trim | Wet areas, outdoor, and commercial jobs. Grade 304 for general use, Grade 316 for coastal and marine environments. |
| Roberts Standard Expansion Joint Trim | Readily available in Black and Grey with rubber insert. 14 sizes per colour covering 8mm to 22mm tile depths in 6mm and 10mm joint widths. |
| Roberts Made-to-Order Expansion Joint Trim | Custom colour-matched expansion joints with Maxisil N silicone insert. 30 trim colours × 23 silicone colours. Available in aluminium, brass, or stainless steel. |
| Roberts Waterstop Trim | Standard and L-Shape profiles for wet area compliance. 48 variants across 8 finishes including Matte Black, Matte Gold, and Brushed Nickel. |
| Demtech Balcony Edge Trim | 55mm anodised aluminium with 12mm drip edge and weep holes. Black or silver finish — can be powder-coated to any Dulux colour. |
| Demtech Water Stop Angle | Budget-friendly AS 3740:2021 compliant waterstop. Three sizes for doorways, bathtub perimeters, and shower bases. |
| BAT Aluminium Tiling Angle | Popular alternative in two grades — Premium (AA) with thicker aluminium for heavy-duty jobs, and Project (PA) as a thinner, more cost-effective option. Wide size and finish range, available from multiple vendors. |
Quick Recommendation Guide
- Standard bathroom wall or floor edge → Roberts Aluminium L-Shape Trim — most colours and sizes available
- Modern square-edge look → Roberts Square Edge Trim in aluminium or stainless steel
- Outdoor balcony edge → Demtech Balcony Edge Trim — 55mm profile with drip edge
- Wet area doorway waterstop → Roberts Waterstop Trim or Demtech Water Stop Angle for a budget option
- Expansion joints (need it now) → Roberts Standard Expansion Trim in Black or Grey — ships immediately
- Expansion joints (custom colour match) → Roberts MTO Expansion Trim with Maxisil N silicone insert
- Coastal or pool area → Roberts Stainless Steel L-Shape Trim Grade 316
Understanding Waterstops & AS 3740 Compliance
A waterstop is a vertical extension of the waterproofing system that prevents moisture migrating beyond the wet area boundary. Under AS 3740:2021 (referenced by the National Construction Code), waterstops are required at:
- Bathroom doorways — vertical leg finishing flush with the finished floor level. The floor membrane must terminate to create a waterproof seal to both the waterstop and perimeter flashing (NCC 10.2.24(c))
- Enclosed hobless showers — waterstop vertical leg finishes at least 5mm above the finished floor level, with the shower screen positioned over the waterstop (NCC 10.2.17, 10.2.32)
- Unenclosed showers — installed at least 1500mm from the shower rose, vertical leg flush with the floor (NCC 10.2.18)
- Bath surrounds — waterstop under the bath lip projecting a minimum 5mm above the tile surface (NCC 10.2.20)
The waterstop must be fixed to the substrate before the waterproofing membrane is applied. The membrane must create a waterproof seal to the waterstop — in some applications, particularly hobless showers, the membrane terminates at the waterstop rather than bonding over it. A waterstop cannot be retrofitted after tiling without stripping the wet area.
Common Questions
How do I choose the right trim size? — Select a trim depth 1–2mm larger than your tile thickness to account for the adhesive bed. A 10mm tile typically needs a 12mm trim. Measure with a vernier caliper before ordering.
Can I get expansion trims in a custom colour? — Yes. Roberts Made-to-Order expansion trims come in 30 trim colours with 23 Maxisil N silicone insert colours — in aluminium, brass, or stainless steel. Standard Black and Grey trims are also available as ready-to-ship stock items.
When are expansion joints required? — AS 3958:2023 requires movement joints at 4.5m intervals externally, up to 9m internally, around fixed objects like columns and doorways, and wherever different substrates meet. Large format tiles need more joints — fewer grout lines means less natural movement accommodation.
Do I need a waterstop at every bathroom door? — Yes. AS 3740:2021 requires a waterstop at all floor-level openings in wet areas, with a vertical leg finishing flush with the finished floor level.
Roberts L-Shape or BAT Tiling Angle? — Roberts is our preferred range with 30+ colours and Maxisil colour-matched options for seamless coordination. BAT is a popular alternative available from multiple vendors in Premium (AA) and Project (PA) grades.
Brands We Stock
Roberts Designs is our preferred brand for tile trims, offering the widest colour and material range including aluminium, brass, and stainless steel profiles. Demtech is our go-to for balcony edge trims and budget-friendly waterstop solutions — all AS 3740:2021 compliant. BAT rounds out the range as a popular alternative with strong multi-vendor availability. We also stock Amark architectural trims.