GENERAL DESCRIPTION

CLASSIFLEX™ MORTAR ADDMIX is a high-solids styrene-acrylic copolymer emulsion with exceptional water resistance and good flexibility, specially developed for use with Portland cement.

When incorporated into cement mortars, plaster, screeds and concrete mixes, CLASSIFLEX™ modifies the cement matrix to improve strength, resilience, adhesion, flexibility, water resistance, workability, flow and long-term durability.

Its high polymer solids content produces a tougher, denser and more water-resistant cementitious system while improving the working properties of the wet mix.

KEY BENEFITS

• Excellent water resistance

• Enhanced adhesion to masonry and cementitious substrates

• Improved flexibility and flexural performance

• Reduced shrinkage and micro-cracking

• Improved abrasion and impact resistance

• Reduced porosity and water absorption

• Improved mortar and plaster workability

• Allows reduced mixing-water demand

• Improved long-term durability

• Helps reduce moisture-related efflorescence

TYPICAL APPLICATIONS

• Plaster and rendering

• Floor screeds

• Concrete decks and balconies

• Shower floors and walls

• Bathrooms and wet areas

• Retaining walls

• Basements and below-ground walls

• Verandas and tiled areas

• Bagging and render coats

• Tile adhesives and cementitious grouts

• Concrete and masonry repair mortars

• Reservoirs, ponds and tanks

CONCRETE DECKS, BALCONIES & SCREEDS

Horizontal cement surfaces are particularly vulnerable to standing water, thermal expansion, surface absorption, weathering, foot traffic and micro-cracking.

CLASSIFLEX™ polymer modification helps produce a stronger and more water-resistant cementitious matrix with improved adhesion, flexibility and durability.

• Reduces water penetration and surface absorption

• Improves adhesion on properly prepared concrete

• Improves resistance to minor movement and micro-cracking

• Increases abrasion and impact resistance

• Improves durability of screeds and repair mortars

• Helps reduce moisture-related efflorescence

CLASSIFLEX™ is highly recommended for exposed decks, balconies, screeds and other cementitious surfaces where improved water resistance, adhesion and durability are required.

PLASTER & MORTAR PERFORMANCE

Improved Workability

• Smooth, creamy and workable consistency

• Easier spreading, trowelling and floating

• Reduced drag during application

• Improved vertical hold

• Reduced sagging and slumping

• Improved finishing control

Improved Adhesion

When correctly prepared and applied, CLASSIFLEX™ modified mortars provide improved adhesion to:

• Brick and block

• Concrete

• Existing sound plaster

• Screeds

• Properly prepared compatible surfaces

Reduced Cracking & Shrinkage

• Improves flexibility of the cementitious system

• Reduces hairline and drying-shrinkage cracking

• Helps reduce crazing

• Allows reduced water demand

• Produces a denser, more resilient cement matrix

DAMP & WATER RESISTANCE

CLASSIFLEX™ reduces the permeability and water absorption of properly mixed and applied cement-based systems.

It is therefore particularly useful for showers, retaining walls, decks, balconies, wet areas and other cementitious surfaces exposed to moisture.

CLASSIFLEX™ can also help reduce:

• Damp staining caused by surface moisture penetration

• Moisture migration through cementitious surfaces

• Paint failure associated with excessive surface absorption

• Efflorescence associated with moisture movement

RECOMMENDED DOSAGE

CLASSIFLEX™ dosage is calculated as a percentage of the weight of cement in the mix.

PRACTICAL DOSAGE GUIDE

Based on an approximate CLASSIFLEX™ liquid density of 1.04 kg/L:

For smaller batches, calculate CLASSIFLEX™ using the same percentage against the actual cement weight.

MIXING INSTRUCTIONS

1. Measure the cement and other dry ingredients accurately.

2. Calculate the required CLASSIFLEX™ quantity according to the cement weight and intended application.

3. Mix all dry ingredients thoroughly before adding liquid.

4. Blend CLASSIFLEX™ with part of the clean mixing water.

5. Add the CLASSIFLEX™ / water mixture gradually while mixing.

6. Add only sufficient additional clean water to obtain the required working consistency.

7. Do not over-water the mix. Excess water reduces strength and increases shrinkage.

8. Mix thoroughly until a smooth and uniform consistency is obtained.

BONDING SLURRY

For bonding new cementitious mortar, plaster or screed to a properly prepared cement or masonry substrate, CLASSIFLEX™ may be incorporated into a cementitious bonding slurry.

Use CLASSIFLEX™ within the recommended high-bond dosage range and mix with Portland cement and only sufficient clean water to produce a smooth brushable slurry.

Apply the slurry evenly to the prepared substrate and apply the new mortar, plaster or screed while the bonding coat remains wet or tacky. Do not allow the bonding coat to dry completely before overcoating.

WATERPROOFING & TANKING

For cementitious waterproofing applications, CLASSIFLEX™ should be used at the higher end of the recommended dosage range.

The substrate must be structurally sound, clean and properly prepared. Dry or highly absorbent cementitious surfaces should be dampened before application, but no standing water should remain.

Apply the CLASSIFLEX™ modified cementitious system continuously and without pinholes, voids or missed areas.

Particular attention must be given to corners, wall-to-floor junctions, penetrations, construction joints and existing cracks.

SURFACE PREPARATION

• Surfaces must be clean, firm, sound and free from dust.

• Remove oil, grease, laitance, loose material, curing compounds and other contaminants.

• Remove loose or defective plaster and concrete.

• Repair substantial cracks and structural defects before application.

• Dampen dry porous cementitious surfaces before application.

• Do not apply onto surfaces carrying standing water.

EFFLORESCENCE

CLASSIFLEX™ reduces water absorption and helps tighten the cement matrix, thereby reducing the movement of dissolved salts through the finished surface.

This can substantially reduce the risk of moisture-related efflorescence.

Complete prevention cannot be guaranteed. Efflorescence may still occur where rising damp, high salt levels, water leaks or continuous moisture exposure are present.

TECHNICAL DATA

APPLICATION CONDITIONS

• Recommended product and application temperature: 5°C–35°C

• Avoid application during rain or adverse weather

• Protect newly applied cementitious work from rapid drying

• Follow normal good-practice curing procedures for cement-based systems

• Clean equipment with water immediately after use

IMPORTANT

• CLASSIFLEX™ is an additive and must be correctly proportioned into the cementitious system.

• Do not compensate for poor-quality sand, incorrect cement ratios or unsound substrates by increasing CLASSIFLEX™ dosage.

• Do not over-water polymer-modified mortar or screed.

• Existing structural cracks, movement joints and active leaks require appropriate repair before waterproofing.

• Actual performance depends on substrate condition, mix design, application thickness, workmanship and curing.

SAFETY

• Keep out of reach of children and animals.

• Avoid ingestion.

• Avoid prolonged skin contact.

• Wear suitable gloves and eye protection during mixing and application.

• If contact with skin occurs, wash thoroughly with soap and clean water.

• If contact with eyes occurs, rinse immediately with plenty of clean water and seek medical attention if irritation persists.

• Remember that Portland cement becomes strongly alkaline when mixed with water and can cause skin and eye irritation.

• Refer to the current Safety Data Sheet before use.

GENERAL

Different substrates, mix designs and environmental conditions require different application systems to obtain optimum results.

Where the application involves structural waterproofing, permanent water immersion, unusual substrates or demanding service conditions, contact Classic Paints for technical advice before commencing work.

The information and recommendations relating to the application and end-use of Classic Paints products are given in good faith based on current knowledge and experience when products are properly stored, handled and applied under normal conditions.

Because materials, substrates, mix designs, workmanship and actual site conditions vary, users remain responsible for determining the suitability of the product and proposed system for the intended application.

DISCLAIMER

No guarantee is implied by the recommendations contained herein since conditions of use, substrate preparation, mix design, workmanship and application are beyond the control of Classic Paints.

In the event of a proven product fault, liability shall be limited to replacement of the defective product only, subject to the applicable terms and conditions of sale.

ISSUE

11/09/2026 — This publication supersedes all previous CLASSIFLEX™ product information.

Technical information is based on available product data and normal application conditions. Users must refer to the latest Product Data Sheet and Safety Data Sheet before use.