Puddle flanges and floor wastes — balcony waterproofing

System Description

Hydraloc PVC puddle flanges are a standard specification for balcony and terrace waterproofing remediation in Australia, particularly where liquid-applied polyurethane, hybrid, or cementitious waterproofing membranes are being applied. The flat PVC flange body is set into the screed at the low point of the drainage fall, and the liquid membrane is applied directly over the flange surface and lapped into the drain opening, creating a continuous, bonded membrane-to-drain junction. PVC puddle flanges are compatible with the majority of liquid-applied membrane systems used in Australian strata remediation — confirm chemical compatibility with the specific membrane product being applied before specifying. The flange is set at the correct height relative to the finished screed surface before priming and membrane application. The membrane manufacturer's specified overlap dimension onto the flange (typically 50–75mm) must be maintained to achieve a compliant junction detail. The 100mm round outlet is the standard sizing for single balcony floor wastes. A grate or tile insert cover is fitted over the drain body after tile installation. Confirm grate compatibility and tile insert dimensions with the supplier before specifying.

System Description

Stainless steel square puddle flanges with tile insert grates are the standard architectural drain specification for tiled balcony and terrace applications in Australian Class 2 strata buildings. The stainless body and flat flange allow torch-on modified bitumen sheet membranes to be heat-bonded directly to the flange surface, and are also compatible with liquid-applied PU and hybrid membranes. The tile insert grate allows a cut tile to be placed in the centre of the grate, creating a near-invisible drain finish in the tiled floor. The stainless puddle flange is set into the screed at the low point of the drainage fall. For torch-on sheet systems, the base sheet and cap sheet are lapped over the stainless flange and torch-bonded to create the waterproof junction. For liquid-applied systems, the membrane is applied over the flange surface with the specified overlap. The tile insert cover is installed after tile fixing is complete. Stainless steel construction provides corrosion resistance appropriate for permanently wet external balcony conditions. Grade 316 stainless is preferred for coastal and marine-exposed locations. Confirm grade with the supplier for the specific project location and exposure level.

System Description

The Schlüter KERDI-DRAIN is an adjustable-height stainless steel point drain system designed to integrate with the Schlüter KERDI bonded waterproofing membrane system, and is also compatible with liquid-applied waterproofing systems when the membrane manufacturer confirms compatibility. The adjustable-height drain body allows the drain to be set to the correct finished floor level after the screed has been applied and the membrane installed, eliminating the height-setting accuracy required with fixed-height flanges. This is a significant advantage in remediation projects where existing screed surfaces may be uneven. The KERDI-DRAIN is available with a stainless steel tile insert grate or a standard stainless grate. The KERDI fabric membrane (or liquid-applied membrane) is lapped and bonded into the drain body at the flange collar, creating a continuous waterproof junction. The adjustable upper section allows the grate to be brought to the correct finished tile height after tiles are laid. KERDI-DRAIN is widely used in both internal wet area and external balcony applications in Australia. For external balcony remediation on Class 2 strata, confirm with the Schlüter technical representative that the selected KERDI-DRAIN variant is rated for external exposure and is compatible with the membrane system being applied.

System Description

Alwitra manufactures adjustable-height point drains designed for use with modified bitumen sheet membrane systems on flat roofs, podium slabs, and large balcony and terrace decks. The Alwitra Turbo Drain and Evalon Drain systems feature an adjustable-height drain body with a bitumen sheet membrane-compatible flange and a controlled-flow outlet designed to regulate stormwater discharge rates in large roof and podium applications. The drain body is available in PVC or stainless steel configurations. For balcony waterproofing remediation on Class 2 strata, the Alwitra drain system is most commonly specified on larger podium slabs, communal terraces, and roof decks where torch-on or cold-applied sheet membrane systems are being used, and where controlled outlet flow is specified to manage stormwater discharge into the building drainage system. Confirm with the Alwitra Australian distributor which product variant is appropriate for the project membrane system and drainage design before specifying.

System Description

Sump outlets are recessed, large-format drainage components used on podium slabs, raised access floor systems, and large external deck areas where the drainage volume, drainage geometry, or structural slab configuration requires a purpose-designed drainage sump rather than a standard puddle flange floor waste. The sump body is recessed into the structural slab, and the membrane is lapped into the sump body rather than bonded to a surface-mounted puddle flange. This product card is included to distinguish sump outlets from standard puddle flanges and to flag that the correct drain type must be confirmed against the project drainage design before specifying. A standard puddle flange is not appropriate for podium slab or raised deck applications where a sump is required — and conversely, specifying a sump-type outlet on a standard residential balcony is unnecessary and adds complexity without benefit. For standard residential balcony applications (single balcony, single floor waste, liquid-applied or sheet membrane system), specify a PVC or stainless puddle flange as listed in Cards 1–4 above. For podium slabs, large communal terraces, or raised access floor systems, confirm the correct drain type with the project waterproofing consultant or hydraulic engineer before specifying.