AP 421

Substrate type
Concrete, cement floors, ALPOL AP 400 floor and ALPOL AP 135 levelling mortar.

Substrate preparation
The substrate should be firm, sound, properly seasoned and free from substances which may impair adhesion. Remove old, loose and peeling material. Widen cracks, patch slightly chipped areas with ALPOL AZ 130 quick-setting mortar or ALPOL AZ 135 levelling mortar. Strengthen loose substrates with ALPOL AG 700 deep-penetrating primer. At least 24 hours prior to pouring the floor, treat the surface with ALPOL AG 703 primer. Apply fibreglass mesh reinforcement to cracked base and areas exposed to stress concentration. Always make perimeter expansion joints (bond Styrofoam or sponge strips to the walls). If expansion joints are present in the substrate, make them in the floor as well.

Instructions for use
Stir the bag contents mechanically with specified amount of cold and fresh water to reach homogeneous and required consistency. Allow 5 minutes and stir the prepared mix again. When mixing and pouring the floor with a mixing unit, add water according to the mixing unit type. Pour the mix onto the substrate, spread with a float or a skimmer blade and remove air voids using a spiked roller. Insufficient substrate priming and incomplete removal of air voids from the floor may cause bubbles to emerge on the surface. The intervals while pouring the floor should not exceed 20 min. After 6 hours from pouring, cut expansion joints to make lattice of rectangles the size of which depends on the floor area. Foot traffic is allowed after 6 hours. Ceramic, terracotta, porcelain stoneware or marble tiles can be fixed as early as after 2 days (provided that substrate humidity is below 4%) using appropriate ALPOL mortar. After 7 days, PVC floor coverings, panels, wall-to-wall carpets and cork flooring as well as mosaic and parquet can be laid on ALPOL AP 421 floor, provided that the floor moisture content does not exceed 2.5% and is in line with the producer’s recommendations. Before such coverings are glued down, grind the floor and prepare it according to the producer’s recommendations. Add appropriate amount of water. Adding too much water will impair floor strength and prolong its setting time, which may also lead to cracking.

Tools
Floor application unit or low-speed electric mixer, basket mixer, float, skimmer blade, spiked roller, spiked shoes, containers, scaled container for dosing water.

Working conditions
Work in ambient temperatures between +5°C and +25°C. Protect fresh floor from excessive drying, moisture and draughts. Do not add any other agents.

Storage
Store in original, unopened packages in dry place – shelf life 9 months from production date. Protect from moisture during transport and storage.

Notes
The specifications and instructions for use are given for the temperature of (20±2)°C and relative air humidity of (65±5)%. The workability may alter in different conditions. Irritating to eyes and respiratory system. Appropriate eye, respiratory system and skin protection measures should be used. Becomes alkaline after mixing with water. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Keep away from children. Use water to remove fresh dirt or ALPOL AI 770 cleaner to remove hardened dirt. The manufacturer accepts no responsibility for damage caused by unskilful or inappropriate use of the product.

General recommendations
When pouring the underlayment, observe the rules related to making structural, contraction and isolation (edge) expansion joints. Construction expansion joints should be provided at the location of the expansion joints in a building structure. Contraction joints should divide the floor into fields not exceeding 30 m2, of a side length up to 6 m. Isolation joints should be used to separate floor layer from other building components (walls, columns, stairs etc.). They are also used where underlayment thickness is changed and at the contact point of various floors (e.g. entrance threshold), as well as to separate rectangular areas in rooms of complex geometry. Work according to building practice, observing health & safety standards and regulations.