RLA Rapid Seal Plus

RLA Rapid Seal Plus is a single-component barrier primer designed to protect flooring installations against residual substrate moisture. It is suitable for prepared internal concrete and cementitious screeds, including damp and green substrates with moisture readings up to 95% RH when tested to ASTM F2170.

The water-based formulation is solvent-free and low VOC. Its purple pigmentation helps installers monitor coverage during brush or roller application.

Rapid Seal Plus requires a minimum two-coat application. The first coat is diluted with an equal volume of water, followed by an undiluted second coat. A 10L pail provides approximately 50m² of completed two-coat coverage, depending on substrate condition and porosity.

Designed for use beneath RLA levelling systems, the primer requires a waiting period of approximately 2–5 hours before levelling and must be completely dry. The levelling compound must be installed within 48 hours of application, or a further primer coat is required.

• Protects flooring installations against residual substrate moisture
• Suitable for moisture readings up to 95% RH when tested to ASTM F2170
• Suitable for substrate pH levels up to 12
• Single-component formulation
• Water-based, solvent-free and low VOC
• Suitable over prepared damp and green concrete and cementitious screeds
• Compatible with RLA levelling systems
• Purple pigmentation helps identify application coverage
• Applied using a brush or medium nap roller
• Approximately 50m² coverage per 10L pail for the two-coat system
• Water cleanup while wet
• Designed for internal applications

• Residual moisture control over internal concrete subfloors
• Vapour barrier priming over cementitious screeds
• Preparation of damp and green concrete with moisture readings up to 95% RH
• Subfloor preparation before applying compatible RLA levelling compounds

• Prepare the substrate in accordance with relevant Australian and New Zealand flooring standards and local building requirements
• Ensure the surface is dry, sound and clean, with wax, grease, oil, polish, old adhesive, curing compounds and other adhesion-inhibiting contaminants removed
• Mechanically prepare the substrate where required to produce a roughened, clean, sound and open porous surface
• Mechanically abrade steel-trowelled, burnished and dense concrete to create an open pore surface
• Vacuum thoroughly and repair voids, holes, damaged areas and static cracks using suitable RLA preparation or repair products
• Do not use solvents or acid etching to clean the subfloor
• Test substrate relative humidity and pH before application; moisture must not exceed 95% RH when tested to ASTM F2170
• Apply only when the substrate temperature is between 10°C and 28°C
• Lightly stir the product before use
• Dilute the first coat with clean water at a ratio of 1 part Rapid Seal Plus to 1 part water by volume
• Apply using a brush or medium nap roller, ensuring full coverage
• Apply the second coat neat, without dilution; a minimum of two coats is required
• Allow the primer to dry completely and observe the specified 2–5 hour waiting period before applying the levelling compound
• Install the RLA levelling system within 48 hours of Rapid Seal Plus application
• If the 48-hour window is exceeded, apply a further coat and allow it to dry before levelling
• Protect the primed surface from contamination before applying subsequent finishes
• Do not use externally, over anhydrite or gypsum-based substrates, or in flooring applications with underfloor heating
• Do not apply where residual moisture exceeds 95% RH or where rising damp is present; seek RLA advice for rising damp or hydrostatic pressure
• Clean tools and equipment with water while the product remains wet