External Wall
WaterproofingBREATHE · BRIDGE · REPEL
A breathable, elastomeric coating system for façades and external walls — a UV-stable, crack-bridging film that repels driving rain from outside while letting trapped moisture escape, ending the damp patches, peeling paint and interior seepage that wet walls cause.
What is External Wall Waterproofing?
External wall waterproofing is a breathable, elastomeric coating system applied to building façades and external walls to stop driving rain from soaking through the masonry — while still letting moisture inside the wall escape as vapour. This balance is the whole point: a wall sealed with a non-breathable film simply traps moisture, blisters and fails, whereas a breathable elastomeric coating repels liquid water from outside yet stays vapour-open. POLYZEN treats cracks and joints first, then builds a UV-stable, crack-bridging coat that flexes with thermal movement and keeps its colour — ending the damp patches, peeling paint, efflorescence and interior seepage that wet external walls cause.
How the System Is Built
An external wall is repaired, sealed at cracks, then coated with a breathable elastomeric film. Tap any layer to see its role.
Top Elastomeric Coat
A second elastomeric coat builds the film to full thickness and provides the UV-stable, colour-retentive weather face that repels driving rain while staying vapour-open. System values: Per TDS.
Engineered & Installed by POLYZEN
External wall waterproofing is delivered as a POLYZEN Applied System — surveyed, designed and installed turnkey by POLYZEN's trained applicators, with crack treatment, coating type and finish specified to your façade's exposure and condition.
Repels Rain, Lets Walls Breathe
A wall fails when it cannot breathe. POLYZEN's system blocks liquid rainwater from outside but stays vapour-permeable, so moisture already in the wall escapes instead of blistering the coating. Add crack-bridging flex and UV stability, and the façade stays dry and good-looking for years. Performance is confirmed on the project specification.
Coating type, number of coats, crack treatment and finish are specified per façade exposure, substrate and condition. POLYZEN confirms finished values on the project specification and does not publish fabricated figures.
The Application Process
Inspect & Assess
Identify damp sources, cracks, plaster debonds and exposure; check the wall is sound and dry.
Clean & Repair
Wash off dirt, algae and loose paint, repair plaster, treat efflorescence, then prime the surface.
Seal & Coat
Fill and band cracks and junctions, then apply two elastomeric coats to full crack-bridging thickness.
Cure & Handover
Controlled cure, final inspection, finish and colour check, and written warranty.
System Specifications
| Property | Detail |
|---|---|
| System Type | External Wall / Façade Waterproofing |
| Delivery | POLYZEN Applied System (turnkey) |
| Coating Type | Breathable elastomeric / acrylic |
| Key Property | Vapour-permeable + water-repellent |
| Movement | Crack-bridging · UV-stable · colour-retentive |
| Build-Up | Primer + Crack Treatment + 2 Elastomeric Coats |
| Orientation | Vertical façades & external walls |
| Coats / DFT | Per Project Specification |
Ideal Applications
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Applied & Warranted
Every POLYZEN external wall waterproofing system is installed by trained applicators and handed over with a final inspection, a finish and colour check and a written system warranty. Warranty terms are confirmed per project scope, façade exposure and substrate condition.
Frequently Asked Questions
Related Waterproofing Systems
Keep the Rain Out. Let Walls Breathe.
Get a façade assessment, coating recommendation and quote for your external walls.