Repair Systems — Basement Water Ingress
Cementitious crystalline tanking systems
Technical product reference for cementitious crystalline waterproofing systems — Xypex, Penetron, and equivalent products — used to tank basement walls and slabs against hydrostatic water ingress from the negative or positive side in Australian Class 2 strata and commercial buildings. Covers crystalline chemistry, application method, negative-side vs positive-side selection, and AS 3600 compliance.
What are crystalline tanking systems?
Cementitious crystalline waterproofing systems are slurry-applied products that penetrate the capillary structure of concrete and react with unhydrated cement particles and water to form insoluble crystalline compounds that fill the capillaries and micro-cracks within the concrete matrix. Unlike surface-applied membranes — which sit on the surface and can delaminate — crystalline waterproofing becomes permanently integrated with the concrete, making the concrete itself less permeable rather than covering it with a separate layer.
Their autogenous (self-healing) property — sealing new cracks that form after application as long as water is present — distinguishes crystalline systems from other waterproofing approaches, and suits basement structures subject to post-construction and seasonal movement. The critical limitation is the substrate: crystalline chemistry needs unhydrated cement to react with, so it cannot be applied to masonry, brick or render, and the concrete pores must be opened (grinding / HP water blast) and the surface free of laitance or a previous membrane. Active running water must be stopped with a hydraulic cement plug before application.
Product Reference
Individual products — one card each — scroll to view all
Xypex Australia
Xypex Concentrate
Crystalline waterproofing slurry — positive / negative side
Xypex Concentrate is a catalytic crystalline waterproofing applied as a cementitious slurry to above- or below-grade concrete, positive or negative side. It reacts with unhydrated cement and water to form an insoluble crystalline structure in the pores and capillaries, resisting high hydrostatic pressure and self-healing new microcracks while water is present. Coverage 0.65–0.8 kg/m² per coat; single coat or the first of a two-coat system with Xypex Modified. Open the pores by grinding / HP water blast and wet-cure. Confirm AS/NZS 4020 potable-water status with Xypex Australia.
Xypex Australia
Xypex Modified
Crystalline second coat / damp-proofing slurry
Xypex Modified is a crystalline waterproofing slurry used as the second coat to chemically reinforce Xypex Concentrate (applied after Concentrate reaches initial set but while still green, <48 h, giving a harder finish), or as a single coat for damp-proofing exterior foundation walls. Coverage 0.65–0.8 kg/m² per coat. It is not used alone for negative-side high-pressure tanking. Wet-cure. Confirm AS/NZS 4020 status with Xypex Australia.
Penetron Australia
Penetron (Standard)
Surface-applied integral crystalline waterproofing
Penetron is a surface-applied integral crystalline waterproofing of Portland cement, specially treated quartz sand and active chemicals, brushed or sprayed to the positive or negative side of concrete. In the presence of moisture it penetrates deeply and forms an insoluble crystalline structure that fills microcracks, pores and capillaries and resists high hydrostatic pressure, with self-healing of cracks over the concrete's life. Slurry coat on hardened concrete; dry-sprinkle 1 kg/m² and trowel into fresh concrete at initial set; 1.6 kg/m² at construction joints. Keep damp for 5 days, protected from sun / wind / frost. Confirm AS/NZS 4020 status with Penetron Australia.
System Comparison
Cementitious crystalline tanking — confirm all selections against the current manufacturer TDS before specifying.
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Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, substrate condition, and structural engineer advice where applicable. Basement and below-ground waterproofing involves hydrostatic pressure — confirm system selection with a qualified waterproofing consultant before specifying. Do not rely on this reference as a substitute for professional advice.
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