Repair Systems — Rising Damp
Renovating salt-resistant plaster systems
Technical product reference for WTA 2-9-04 compliant renovation plaster systems for replastering masonry walls after chemical DPC injection — covering salt tolerance, pore structure, brand comparisons and system selection.
What are renovating salt-resistant plaster systems?
Renovating salt-resistant plaster systems (also called WTA renovation plasters) are specialist replastering products designed for masonry walls drying out after rising damp treatment. They differ fundamentally from standard plasters in their pore structure — WTA renovation plasters are formulated with an enlarged pore matrix that accommodates salt crystallisation within the plaster body without surface spalling or failure.
When a wall has been subject to rising damp over many years, the masonry and existing plaster become loaded with hygroscopic salts — primarily nitrates, chlorides and sulphates leached from the ground. Even after DPC injection stops further capillary rise, these salts remain in the wall fabric and continue to crystallise as the wall dries. Standard gypsum or Portland cement plasters cannot tolerate this salt environment and will fail rapidly through spalling, blistering and loss of adhesion.
The WTA 2-9-04 renovation plaster standard defines the minimum pore volume, mechanical properties and salt tolerance required. Remmers SP renovation plasters are the most established WTA-compliant products in Australia, used as the follow-on plastering system after Remmers Kiesol or Kiesol C DPC injection.
Do not confuse with:
- Standard gypsum plaster or cement render — not salt-resistant — will fail on rising damp walls
- Crystalline waterproofing slurries (Xypex, Vandex Super) — active waterproofing against hydrostatic pressure — not a renovation plaster
- Breathable renders (NHL lime, silicate render) — for exterior application — different product category
- Waterproof cementitious coatings — a surface barrier coating — not the same as a salt-tolerant renovation plaster with enlarged pore structure
Product Reference
Individual products — one card each — scroll to view all
Remmers Australia
Remmers SP Top White (WTA renovation plaster)
WTA renovation plaster — fibre-reinforced, salt-storing
Remmers SP Top White is a white, fibre-reinforced WTA renovation plaster (Sanierputz) for damp, salt-laden masonry. It carries an active pore-space volume >50% (high salt-storage capacity), is sulphate-resistant with low active alkali (SR/NA), pore-hydrophobic, fibre-reinforced and diffusion-open (drying-promoting). Applied 10–30 mm per layer (up to 40 mm in two layers; ≥20 mm total per WTA), ≈17 kg/m² at 20 mm. It is the follow-on plaster after Remmers Kiesol / Kiesol C DPC injection. Confirm compressive-strength class and current AU availability with Remmers Australia.
Mapei Australia
Mapei Mape-Antique (Rinzaffo + MC)
Macroporous dehumidifying render system — lime + Eco-Pozzolan
Mapei Mape-Antique is a cement-free (lime + Eco-Pozzolan) macroporous dehumidifying render system for damp, salt-laden masonry: Mape-Antique Rinzaffo (EN 998-1 type GP, CS IV; ≤5 mm keying coat; 7.5 kg/m² @ 5 mm; µ ≤30; 20 kg bags) plus Mape-Antique MC (EN 998-1 type R, CS II; 20–30 mm/layer render; 15 kg/m² per cm; fresh porosity >20%; µ ≤10; ~60 min workability; 14–16% water; 25 kg bags), finished with a Mape-Antique fine coat. Confirm WTA 2-9-04 status and current AU products with Mapei Australia.
Sika Australia
Sika SikaMur Dry / SikaMur-1000 SP
Ready-mixed breathable macroporous renovation (dehumidifying) mortar
Sika's renovation render for rising-damp / salt-damaged masonry is the SikaMur range — SikaMur Dry and SikaMur-1000 SP are ready-mixed, breathable, high-porosity macroporous dehumidifying renovation mortars to EN 998-1 Class R, applied by machine or hand and finished with SikaMur Finish. (Note: the Sika Vandex range is crystalline tanking / waterproofing, not a renovation plaster.) The cited SikaMur TDS are EU/global — CONFIRM current Australian availability, thickness, coverage and compressive class with Sika Australia.
System Comparison
Renovating salt-resistant plasters — confirm all selections against the current manufacturer TDS before specifying.
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Do not apply standard gypsum or cement plaster to rising damp walls — it will fail
- Gypsum plaster is soluble in the presence of moisture and salts — it will dissolve, swell and delaminate rapidly on a rising damp wall
- Standard Portland cement render is not salt-tolerant — it has insufficient pore volume to accommodate salt crystallisation and will spall and delaminate
- Only WTA 2-9-04 compliant renovation plasters (Remmers SP series or equivalent) have the confirmed pore structure to manage hygroscopic salt crystallisation during the wall drying-out period
- Stripping old plaster to masonry and replastering with standard materials without a WTA renovation plaster is the most common failure in rising damp remediation
Disclaimer
Information is general only. Product selection must be confirmed against project requirements, substrate condition, salt loading, manufacturer technical data sheets, and applicable standards including WTA 2-9-04. Do not apply renovation plaster without first completing chemical DPC injection. Do not rely on this reference as a substitute for professional advice.