| HS Code | 999577 |
| Product Name | Rigid RDP for Cementitious Waterproofing |
| Appearance | White powder |
| Bulk Density | 400-600 g/L |
| Particle Size | ≥95% through 400 mesh |
| Ash Content | 8-12% |
| Ph Value | 6.0-8.0 (10% aqueous solution) |
| Minimum Film Forming Temperature | 0-5°C |
| Tensile Strength | ≥2.0 MPa |
| Elongation At Break | 50-100% |
| Water Resistance | Excellent |
| Adhesion Strength | ≥1.0 MPa to concrete |
| Storage Stability | 24 months |
| Free Flow | Free flowing, no lumps |
| Dispersibility | Fully redispersible in water |
As an accredited Rigid RDP for Cementitious Waterproofing factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Rigid RDP for cementitious waterproofing is supplied in 20 kg moisture-proof sealed bags, ensuring easy handling and stable storage. |
| Container Loading (20′ FCL) | 20′ FCL shipment of Rigid RDP powder, packed in bags on pallets, for cementitious waterproofing applications. |
| Shipping | Rigid RDP (redispersible polymer powder) for cementitious waterproofing ships as a dry, free-flowing powder in moisture-proof multi-layer bags or drums. Keep pallets sealed, dry, and away from direct sunlight and rain. Avoid skin/eye contact and airborne dust. Store below 30°C in ventilated area; handle with care. |
| Storage | Store Rigid RDP in a cool, dry, well-ventilated area, away from moisture, direct sunlight, and heat sources. Keep in its original, unopened packaging with the seal intact. Avoid exposure to humidity, as caking may occur. Use within the manufacturer’s stated shelf life, typically six to twelve months, under proper storage conditions. |
| Shelf Life | Shelf life is 12 months from production when stored unopened in a cool, dry place, protected from moisture and sunlight. |
On blind-side concrete retaining walls where excavation space is omitted and only the interior face remains accessible, a polymer-modified mineral slurry is applied to resist back-side water migration through tie-bolt holes, cold joints, and casting imperfections. The formulation relies on the rigid redispersible polymer powder to refine capillary pores and increase wet shear adhesion to damp substrates rather than to form an elastomeric film. Compliance for this service is driven by EN 12390-8:2019, which measures water penetration depth under 0.5 MPa hydrostatic pressure for 72 h; capillary water absorption is determined by EN 1015-18:2002, while water-vapour transmission is reported according to EN ISO 7783:2018 to confirm that the render does not trap moisture behind the slab. The rigid RDP dosage is kept between 1.8 wt% and 2.5 wt% of total dry mortar mass. Above this range, the render loses enough vapour permeability to produce a secondary condensation plane at the render-substrate interface; below this range, cohesive resistance to negative-side moisture reduces. Dry-mix production is run on a counter-current planetary mixer with aggregate moisture controlled below 0.2% before the RDP is metered into the final mixing sequence. Plant experience shows that charging the RDP too early into hot aggregate lifts powder clumping and creates silo discharge blockages at the 15 mm slot aperture. On site, the substrate is cleaned by 180–250 bar high-pressure water jetting, blowholes and tie-bolt recesses are cut open, and a bonding slurry is applied by stiff brush at 1.0–1.5 kg/m². The main render is placed in two passes totalling 10–15 mm, either by stainless trowel or by rotor/stator spray plastering machine with a 6 mm continuous mixing chamber and 0.5 m³/min compressed air supply. Wet curing under polyethylene sheeting continues for 5–7 days. Terminal product formats include 25 kg moisture-barrier bags and 1,000 kg silo deliveries for high-volume basement projects. The finished systems are supplied as negative-side waterproofing renders, concrete tanking slurries, and internal basement water-barrier mortars for lift pits and underground parking ramps. Published data for this specific rigid-polymer configuration is limited; substrate-specific pull-off tests are required because standard porosity blocks do not reproduce cold-joint suction or residual form-release contamination.
When a cementitious slurry is used beneath ceramic tile in continuously wetted shower floors, the specification is drawn from EN 14891:2017, which evaluates polymer-modified cementitious materials as category CM liquid-applied water impermeable products. The rigid RDP is dosed at 3.5 wt% to 6.0 wt% of the dry powder premix, corresponding to a polymer-cement ratio of approximately 0.08 to 0.13 by mass. The lower boundary is fixed by the requirement for a continuous polymer film across the cementitious matrix after 24 h ambient cure; the upper boundary is governed by the need to maintain compressive strength above 25 MPa at 28 days when tested according to EN 12190:1998 and by the need to avoid excessive trowel drag during application. In dry-mix production, the powder is blended in a twin-shaft paddle mixer with a cooling jacket that holds material temperature below 35°C; post-mixing product passes over a 250 µm vibrating screen before bagging to remove polymer agglomerates. On site, the powder is added to clean water under a low-shear paddle mixer at 400–600 rpm, mixed for 2–3 minutes, left to slake for 5 minutes, and remixed for 30 seconds. The slurry is applied by 3 mm notched trowel or brush in two perpendicular coats, each at a wet-film thickness of 1.0–1.5 mm. Over-application beyond 2.0 mm in one pass on low-suction substrates is a known field failure because surface skinning traps bleed water and produces intercoat blisters. Terminal products are packaged as 20 kg plastic-lined paper bags or 5 kg pails for small wet-room kits. Finished end-product types include under-tile waterproofing membranes, shower-floor sealing kits, bathroom wall tanking compounds, and wet-room junction band systems. The same compound may be used for wall-floor coving areas when reinforced with a polyester fleece strip in the first wet coat.
Exterior podium decks and balconies impose a different regime because the membrane must absorb thermal movement, withstand freeze-thaw saturation, and remain watertight beneath a bonded tile assembly. The base specification typically requires a liquid-applied water-impermeable product under EN 14891:2017 with additional coating characterisation according to EN 1062-1:2004 for vapour permeability and liquid-water transmission. Rigid RDP is incorporated at 3.0 wt% to 4.5 wt% of the dry powder component. Above 4.5 wt%, the coalesced polymer film increases tensile strength but reduces the elongation needed to bridge cyclic thermal cracks in the aged cementitious layer; therefore a polyester or glass-fibre mesh is embedded in the first coat to transform crack stress into distributed fibre bridging. The production process begins with dry blending at 1,000–1,500 kg batch size in a planetary counter-current mixer; the RDP is introduced after the cement and silica sand have passed through a 0.5 mm sieve, and the finished dry mortar is held in closed silos to limit humidity uptake above 60% RH. On the deck, the concrete surface is primed with a diluted slurry at 0.4–0.6 kg/m². The first membrane coat is applied by trowel or airless spray mortar pump at 20–30 bar with a 4–8 mm orifice. The reinforcement mesh is embedded within 60 minutes of first-coat application; delayed embedment results in air pockets and inadequate fibre wetting, which is a documented site failure on large podiums. A second coat is applied at a wet-film thickness of 1.0–2.0 mm after the first coat has hardened to a matte, finger-dry surface. Terminal product types include 25 kg bags of balcony waterproofing slurry, bucket-mix deck membrane kits, and project-specific bulk silo deliveries. The cured system is used as an under-tile drainage membrane on elevated decks, external balcony floors, and walkway terraces where structural movement is controlled by substrate joints.
| Application scenario | Primary standard | Property controlled | Rigid RDP dosage |
|---|---|---|---|
| Negative-side basement render | EN 12390-8:2019, EN 1015-18:2002 | Water penetration under 0.5 MPa; capillary absorption | 1.8–2.5 wt% |
| Under-tile wet-room membrane | EN 14891:2017 | Water impermeability; tensile adhesion | 3.5–6.0 wt% |
| Exterior podium deck membrane | EN 14891:2017, EN 1062-1:2004 | Crack bridging; vapour permeability | 3.0–4.5 wt% |
| Water-retaining concrete repair | EN 1504-3:2005 class R4 | Compressive strength; bond strength | 1.5–3.0 wt% |
| Industrial kitchen floor screed | EN 13813:2002 | Compressive class; slip resistance | 2.0–4.0 wt% |
| Potable-water tank lining | BS 6920-1:2014 | Taste; odour; total organic carbon | 2.0–3.5 wt% |
Within clarification basins, wet wells, and chlorination channels, polymer-modified repair mortars restore spalled or eroded concrete while limiting liquid ingress through the repair layer. The repair material is specified under EN 1504-3:2005 as a structural repair product of class R4; compressive strength is determined by EN 12190:1998, pull-off adhesion by EN 1542:1999, and capillary absorption by EN 13057:2002. Rigid RDP is added at 1.5 wt% to 3.0 wt% of the dry mortar mass and is metered only after the low-shrinkage cementitious binders and graded aggregates have been homogenized, preventing polymer particle enrichment on fine fractions. The production line uses a twin-shaft batch mixer with load-cell accuracy of ±0.5% for additions above 2 kg; final powder is discharged through a 500 µm safety screen to remove agglomerates that would otherwise produce soft patches in sprayed repairs. On the treatment surface, the concrete is prepared by abrasive blast or 120–180 bar high-pressure water jetting to expose aggregate, then brought to a saturated surface-dry condition before repair. The mixed mortar is applied by hand trowel for shallow profiles or by dry-spray gunite equipment for overhead and vertical sections; layer thickness is built in 20–40 mm passes without exceeding the open time of the bonding slurry. Quality control includes pull-off tests on 50 mm diameter dollies at 7 days with a minimum documented adhesion value established from the project’s structural repair specification. Terminal products are packaged as 25 kg bags of water-retaining concrete repair mortar, 1,000 kg bulk silo grade for large clarifier re-lining, and dry-spray gunite versions for basin wall reinstatement. The finished product type is a rigid structural repair mortar with water-resistant cured matrix, not a flexible joint sealant.
Because food-processing floors are simultaneously exposed to hot water, organic acids, and heavy wheeled traffic, the screed layer must combine low capillary absorption with high compressive strength and cleanable joint-free surface geometry. The screed is specified under EN 13813:2002 as a cementitious screed material class CT-C35-F7; slip resistance is measured according to EN 13036-4:2011 on the finished surface, while water absorption is checked by EN 1015-18:2002. Rigid RDP is dosed at 2.0 wt% to 4.0 wt% of the total dry mortar mass. This window balances the increased toughness of the hydrated paste against the need to maintain a dense, low-porosity surface that can be cleaned with 80°C hot water without polymer softening. In production, the dry mix is blended in a continuous flow screw mixer at 8–12 m³/h, and the RDP is added through a vacuum-assisted side port after the aggregates have been dried to below 0.2% residual moisture. On site, the mortar is pump-applied with a rotor/stator screed pump at 25–40 L/min discharge and compacted by horizontal rodding before steel-trowel finishing. Curing compounds are generally avoided because they can contaminate food-contact surfaces; instead, the slab is covered with polyethylene sheeting for 72 h and then allowed to air-dry before chemical cleaning. Terminal products are packaged as 30 kg bags or 1,200 kg silo deliveries for industrial flooring contractors. The finished end-product types include pumpable waterproofing screeds, floor coving mortars, and sloped drainage build-up layers for commercial kitchens and dairies.
Linings for concrete reservoirs and drinking-water tanks require a cementitious mortar that will not release taste, odour, or excessive organic carbon into the stored water. The product is assessed under BS 6920-1:2014 for non-metallic materials in contact with water intended for human consumption; additional migration testing follows the relevant BS 6920 part for total organic carbon and turbidity response. Rigid RDP is limited to 2.0 wt% to 3.5 wt% of the dry powder premix because the polymer phase introduces soluble organic fractions that increase total organic carbon in stagnant test water. Below 2.0 wt%, the cured lining lacks the crack-control and adhesion properties required for vertical concrete surfaces; above 3.5 wt%, the batch may fail potable-water leaching criteria unless the polymer has been specifically purified for low residual monomer and low surfactant content. In manufacture, the dry mortar is blended in a dedicated stainless-steel ribbon mixer with all contact parts meeting food-grade hygiene practice; ambient storage is held below 60% RH because moisture uptake before mixing accelerates polymer agglomeration. On site, the powder is mixed with potable water at 20±2°C using a low-shear mixer, applied by brush, trowel, or airless spray in two thin passes totalling 2.0–3.0 mm, and cured under damp hessian for 72 h before the tank is rinsed and disinfecting is performed according to water-utility procedure. Terminal product formats include 25 kg paper bags with moisture-block liner and bulk silo deliveries to water-treatment contractors. The finished product types are potable-water tank linings, clear-well repair slurries, and water-retaining basin coatings. They are not formulated for continuous exposure to aggressive chemical disinfectants at concentrations above normal municipal water treatment levels.
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Rigid RDP for Cementitious Waterproofing is a redispersible polymer powder based on a vinyl acetate–ethylene/vinyl acetate–versatate copolymer matrix, supplied as a free-flowing off-white powder. Typical dry-powder specification limits include bulk density 400–600 g/L, residual moisture not exceeding 1.5% by ISO 3251, ash content of 8–12% after incineration at 450 °C in accordance with ISO 3451-1, and pH 6.5–8.5 when dispersed at 50 wt% solids in demineralised water. The powder is intended for dry-mix cementitious waterproofing slurries, trowel-applied rigid sealing coats, and repair mortars where high compressive strength and limited viscoelastic deformation are required. It is not formulated for direct site addition to already mixed mortars; incorporation must occur by dry blending with Portland cement, graded quartz or quartz–kaolin aggregates, and mineral fillers before water addition.
Production-scale spray drying is performed with inlet air temperatures of 130–170 °C and outlet temperatures of 60–70 °C; higher outlet temperatures cause surface skin formation on powder particles and reduce redispersibility. Batch-to-batch variation in residual moisture is controlled below 1.5%, and the dried powder is screened through a 250 µm mesh to remove oversized agglomerates. Powder samples from production lots are re-dispersed in deionised water at 50% solids and passed through a 100 µm screen; residue should remain below 0.5% to avoid surface defects in the waterproofing layer. The protective colloid system is based on polyvinyl alcohol, which controls re-dispersion stability and influences early adhesion to damp substrates.
The effective dosage window is typically 2.0–5.0 wt% of total dry mix. Below 2.0 wt%, capillary water uptake measured under EN 1015-18 remains above 0.10 kg/(m²·min0.5) after 24 h immersion, and dried coats show pinhole defects under transmitted-light inspection. Above 5.0 wt%, 28-day compressive strength measured by ASTM C109/C109M-21 falls by 12–15% relative to an unmodified control because the polymer phase disrupts the continuous hydrating cement skeleton. Addition of 0.3–0.5 wt% of a polycarboxylate ether powder can partially offset the high-dosage strength decline, but it extends set time and may reduce early water resistance. Published data for this specific configuration is limited; formulation validation should be performed against EN 14891:2017 rather than extrapolating from flexible VAE data.
Dry-mix producers handling Rigid RDP in continuous ploughshare mixers should pre-dry aggregates at 105 °C to a final moisture content below 0.2% before polymer addition. In horizontal ploughshare mixers with usable volumes of 500–1000 L, uniform distribution of the polymer powder is typically reached after 60–120 s at a Froude number above 3.0; shorter mixing times produce polymer-rich agglomerates that survive final screening and appear as soft lumps on the wet substrate. At the job site, a low-speed paddle mixer at 400–600 rpm is used with 28–34 wt% clean water based on dry powder mass. Pot life at 23 °C is 45–60 min. Application may proceed by stiff-bristle brush, steel trowel, or airless spray with a 4–6 mm nozzle at 60–80 bar; a single wet coat of 1.0–1.5 mm is applied, followed by a second coat after 6–8 h but before complete surface drying.
After mixing, the redispersible powder releases vinyl acetate–ethylene copolymer particles with an average redispersed particle size of 0.5–5 µm; polyvinyl alcohol protective colloid remains in the aqueous phase and acts as a temporary plasticiser during film coalescence. The rigid grade is characterised by a dried-film glass transition temperature of 16–22 °C by differential scanning calorimetry according to ISO 11357-2 and a minimum film formation temperature of 12–18 °C under ISO 2115. This thermal profile produces a polymer film with higher tensile modulus and lower elongation than flexible VAE powders, which is appropriate for rigid waterproofing layers subjected to low substrate movement. Flexural strength development in a 1:2:0.5 cement:quartz:microsilica mortar at 4.5 wt% addition is commonly 8.0–10.0 N/mm² at 28 d when tested under EN 196-1, while elongation at break of the isolated polymer film is 10–15% under ISO 527-2.
The rigid polymer phase reduces water permeability by coalescing in the capillary pores and by forming a continuous film at cement–aggregate interfaces. In contrast, flexible VAE powders with high ethylene content typically exhibit dried-film glass transition temperatures from −15 °C to −5 °C and film elongation from 30–60%, which supports crack bridging in membrane systems but lowers compressive strength and increases creep under sustained hydrostatic pressure. The rigid grade is therefore selected for basement tanking slurries, lift pits, and rigid screeds where crack-bridging requirements are low but compressive load-bearing capacity and resistance to water penetration are controlling. For projects requiring movement accommodation or crack-bridging performance above 0.4 mm at −5 °C, flexible RDP grades should be used instead.
Representative property ranges for a cementitious waterproofing mortar at 4.5 wt% addition are summarised below. The values are compiled from producer technical literature and should be re-validated for site-specific aggregate grading and cement type.
| Property | Rigid RDP | Flexible VAE RDP | Test method |
|---|---|---|---|
| Dried-film glass transition temperature | 16–22 °C | −15 to −5 °C | ISO 11357-2 |
| Minimum film formation temperature | 12–18 °C | 0–5 °C | ISO 2115 |
| Flexural strength at 28 d, 4.5 wt% addition | 8.0–10.0 N/mm² | 4.0–6.5 N/mm² | EN 196-1 |
| Compressive strength at 28 d, 4.5 wt% addition | 28–35 N/mm² | 18–25 N/mm² | ASTM C109/C109M-21 |
| Elongation at break of isolated polymer film | 10–15% | 30–60% | ISO 527-2 |
| Water absorption after 24 h immersion | 6–9% | 10–15% | EN 1015-18 |
These differences are most visible in membrane systems subjected to low-temperature movement. At −10 °C, the rigid polymer phase approaches its glass transition, and crack-bridging capacity drops below 0.1 mm, while flexible VAE grades retain crack-bridging values above 0.4 mm in EN 14891:2017 tests. Conversely, at 40 °C, flexible grades soften and may allow aggregate displacement under compressive load, while the rigid grade maintains surface hardness and dimensional stability. The rigid product also exhibits lower air-entrainment during mixing because the high-Tg polymer does not coalesce early in the mixer; this reduces unintentional air voids in the waterproofing layer.
Application performance is reduced on low-porosity substrates with surface tensile strength below 1.5 N/mm². Polished concrete, old epoxy-coated surfaces, and dense vibrated concrete should receive a compatible cementitious pore closer or primer before the Rigid RDP waterproofing slurry is applied. Without a pore closer, film thickness becomes non-uniform, and entrapped air bubbles form under the first coat; after 24 h water immersion, blisters appear at polymer-rich zones. The open time at 20 °C and 55% RH is 10–15 min for a 1.0 mm wet coat; above 30 °C or below 30% RH, open time falls below 5 min, and wetting of the surface must be adjusted with a damp sponge, not excess mixing water.
Two-coat application by brush is the preferred method for vertical surfaces; each coat is applied at 1.0–1.5 mm wet thickness. The second coat is applied at right angles to the first to reduce pinhole channels. On horizontal surfaces, notched trowels with a 3 mm notch depth produce a final dry film thickness of 2.0–2.5 mm after two coats, which is generally sufficient for low-head hydrostatic conditions up to 0.5 bar when the substrate is stable. For higher water pressure, film thickness and reinforcement with a mesh are required. Reinforcement with a 100 g/m² alkali-resistant glass fibre mesh at the first coat can increase crack resistance but does not replace substrate movement joints. Curing with a fine water mist at 6–8 h intervals for 48 h after final set improves cement hydration and reduces shrinkage cracking.
The powder is not suited for continuous immersion without a protective cementitious wear layer, because prolonged water uptake beyond 72 h may cause polymer swelling and loss of abrasion resistance. It should not be combined with calcium sulfate–based plasters or high-alumina cement in the same mix, because rapid set and reduced pH can delay polyvinyl alcohol dissolution and produce brittle coats. Avoid combination with amine-based additives at concentrations above 0.2 wt% of dry mix; such combinations may induce premature film flocculation and reduce re-dispersibility before hydration has progressed. For ambient temperatures below 5 °C, film coalescence is incomplete, and application should be postponed unless heated enclosures maintain substrate temperature above 8 °C. When the mixed slurry is subjected to high-shear mixing above 800 rpm for more than 3 min, polymer particle agglomeration can occur, producing visible pinholing in the cured membrane.
