Repair Systems — 03 — Facade & External Envelope
WP termination — liquid-applied membrane
Technical product reference for liquid-applied waterproofing membrane termination systems at balcony door hobs on Australian Class 2 strata buildings. Covers polyurethane, acrylic and hybrid liquid-applied membranes used at the hob-to-door-frame interface — the critical waterproofing termination detail that prevents balcony water entering the interior at the door threshold.
What are liquid-applied membrane systems for balcony hob waterproofing termination?
Liquid-applied waterproofing membranes are the most common membrane type used for balcony hob and threshold waterproofing in Australian Class 2 strata buildings. They are applied as a liquid that cures to form a seamless, flexible membrane that conforms to the substrate geometry — including the hob upstand — without the need for prefabricated sheet or torch-on products at complex junctions.
Product Reference
3 products — liquid-applied waterproofing membrane systems — scroll to view all
Sika® Sikalastic®-560 / SikaMembrane®-720 liquid-applied membrane
Liquid-applied waterproofing membrane — balcony hob termination — Sika
System Description
Sika liquid-applied waterproofing membranes (Sikalastic-560, SikaMembrane-720 or current equivalent) are used for balcony waterproofing including the hob and threshold termination detail. The membrane is applied in multiple coats to the prepared hob substrate, with reinforcement mesh (e.g., Sika® Reemat or equivalent) embedded in the first coat at all internal angles and changes of direction. The membrane is taken up and over the hob upstand and terminated at or above the top of the hob with a sealant termination bead or under a metal termination bar. The substrate must be primed with the compatible Sika primer (e.g., SikaPrimer MB or current equivalent) — confirm the correct primer for the substrate type. Minimum dry film thickness (DFT) must be confirmed in the TDS — typically 1.0–2.0mm depending on the product and application class. Confirm the current product name and TDS with Sika Australia before specifying — product ranges change periodically. All waterproofing at the hob must comply with AS 3740 and the project specification. TODO: owner confirm — confirm current Sika membrane product and primer selection for hob application.
Technical Properties
- Liquid-applied PU or hybrid membrane — applied in multiple coats to achieve minimum DFT
- Reinforcement mesh required at all internal angles and changes of direction — embedded in first coat
- Compatible Sika primer required — confirm correct primer for concrete or masonry substrate
Limitations
- Substrate must be clean, sound, primed and dry — wet or contaminated substrate will cause adhesion failure
- Minimum DFT must be achieved — confirm number of coats and application rate with TDS
- Reinforcement mesh must be installed at all internal angles — omission is a common waterproofing failure mode
PROCUREMENT SOURCES
Confirm current product name, DFT requirements and primer selection before ordering.
Mapei Mapelastic® AquaDefense / Mapelastic® Smart liquid membrane
Liquid-applied waterproofing membrane — balcony hob termination — Mapei
System Description
Mapei liquid-applied waterproofing membranes including Mapelastic AquaDefense (one-part ready-to-use) and Mapelastic Smart (two-part) are used for balcony waterproofing including the hob and threshold termination. AquaDefense is a one-part product suitable for internal and external wet areas, while Mapelastic Smart is a two-part flexible cementitious membrane for more demanding external balcony applications. Both require reinforcement mesh (Mapei Mapenet 150 or equivalent) embedded in the first coat at all internal angles and changes of direction at the hob. The membrane is taken up and over the hob upstand and terminated at or above the top. Prime with compatible Mapei primer — confirm correct primer for the substrate type (concrete, masonry, mortar) with Mapei TDS. Minimum DFT must be achieved — confirm with current TDS. Confirm current product name and TDS with Mapei Australia before specifying. TODO: owner confirm — confirm Mapei membrane product selection for balcony hob application.
Technical Properties
- One-part (AquaDefense) or two-part (Mapelastic Smart) liquid membrane — select grade for application
- Mapei Mapenet reinforcement mesh at all internal angles — embedded in first coat
- Compatible Mapei primer required — confirm for concrete or masonry substrate
Limitations
- Substrate must be primed and dry — wet substrate prevents adhesion
- Two-part Mapelastic Smart has a mixing and pot life requirement — confirm for site temperature
- Reinforcement mesh at angles is mandatory — omission leads to cracking at changes of direction
PROCUREMENT SOURCES
Confirm current product name, DFT requirements and primer selection before ordering.
Ardex 8+9™ rapid waterproofing compound / Ardex WPM liquid membrane
Rapid liquid-applied waterproofing membrane — balcony hob — Ardex
System Description
Ardex waterproofing products for balcony hob applications include Ardex 8+9 Rapid Waterproofing Compound (a two-component rapid-set cementitious membrane) and the Ardex WPM range of liquid-applied membranes. Ardex 8+9 is particularly suited to remedial balcony programs where a fast return to service is needed — its rapid-set formulation allows tiling or surface treatment to commence within hours rather than days. The membrane is mixed (2:1 liquid to powder by volume) and applied in two coats with Ardex Fibreglass Tape embedded in the first coat at all internal angles and changes of direction including the hob base and top. The membrane is taken up and over the hob upstand and terminated at or above the top. Priming requirements confirm with current Ardex TDS. All balcony WP must comply with AS 3740. Confirm the most appropriate current Ardex product for the specific hob application with Ardex Australia before specifying. TODO: owner confirm — confirm Ardex product selection for hob application.
Technical Properties
- Ardex 8+9 rapid-set two-component cementitious membrane — fast track for early return to service
- Ardex Fibreglass Tape at all internal angles and changes of direction — including hob base and top
- Priming requirements per current Ardex TDS — confirm for specific substrate
Limitations
- Mixing ratio is critical — 2:1 liquid to powder by volume — incorrect ratio affects waterproofing performance
- Reinforcement tape at all angles is mandatory — omission is a common failure mode
- Substrate must be primed and in SSD condition — confirm with current Ardex TDS
PROCUREMENT SOURCES
Confirm current product name, DFT requirements and primer selection before ordering.
System Comparison
Side-by-side comparison of liquid-applied membrane systems for hob waterproofing termination. Confirm current product names and DFT before specifying.
| Product system | Brand | Parts | Set speed | Mesh type | DFT | Primary use |
|---|---|---|---|---|---|---|
| Sika Sikalastic-560 / SikaMembrane-720 | Sika | Two-part | Standard | Sika Reemat | Per TDS | Sika liquid PU/hybrid membrane for balcony hob waterproofing — confirm current product name |
| Mapei Mapelastic AquaDefense / Smart | Mapei | 1 or 2-part | Standard | Mapenet 150 | Per TDS | Mapei one-part or two-part membrane for hob — select grade for internal vs external exposure |
| Ardex 8+9 / Ardex WPM | Ardex | Two-part | Rapid | Ardex fibreglass tape | Per TDS | Ardex rapid-set cementitious membrane — fast return to service for remedial balcony programs |
Critical notes for waterproofing membrane termination at door hobs:
- Liquid membrane termination at the door frame is one of the highest-risk details in balcony waterproofing — the membrane must bond directly to the door frame aluminium and turn up to required height; any gap in this bond allows water entry
- Aluminium door frames must be cleaned, degreased and primed with a membrane-compatible aluminium primer before membrane application — membrane will not bond adequately to bare, contaminated or anodised aluminium without preparation
- Membrane must be applied at minimum DFT (dry film thickness) as specified by the manufacturer — thin spots at the hob-to-frame junction are a common cause of premature failure
- Detail reinforcement mesh or fabric must be embedded in the membrane at all internal angles and junctions — unreinforced membrane at angles cracks under movement and thermal cycling
- Do not apply liquid membrane over damp or green concrete — substrate must be dry and cured to the membrane manufacturer's minimum moisture content specification before application
- Liquid membrane termination systems must comply with AS 3740 minimum heights above the finished floor level — confirm required height against the relevant NCC Performance Requirement
Disclaimer
This page provides general technical information only. Waterproofing membrane system selection, DFT requirements, primer compatibility and AS 3740 height compliance must be confirmed by a licensed waterproofer and qualified remedial practitioner against project-specific conditions.