AT 302

Substrate type
Base plaster, precast concrete walls and ceilings and poured in boarding systems, as well as walls made of silicate and cellular concrete block walls with narrow gaps.

Substrate preparation
The substrate must be clean, sound, dry and free from dirt, dust and grease. Weak surfaces should be primed with ALPOL AG 700 deep-penetrating primer,  whereas highly absorbing surfaces with  APOL AG 708 primer. On smooth surfaces of precast concrete and poured in boarding systems use ALPOL AG 702 primer to create a bonding layer. During application of the finishing layer (screed) on freshly applied base plater coatings e.g. ALPOL AT 300, AT 301, AT 306, allow at least a 7-day interval per each centimetre of base plaster coat thickness, and moisten the base plaster with copious amount of water immediately prior to the screed application. Points susceptible to cracking, e.g. at interfaces of different construction materials and corners of openings, should be strengthened with fibre glass reinforcing mesh size at least 8x8 mm, by embedding it in ALPOL AZ 130 quick-setting or ALPOL AZ 135 levelling mortar or in the plaster.

Instructions for use
Use the plaster unit with to apply the plaster onto the entire area to be treated during one working cycle. The plaster should be applied in two stages. At first, apply the plaster on the surface, skim with a feather edge (H-type darby), patch any possible gaps and level out the entire surface. Leave the surface treated that way for around 6-12 hours (depending on substrate absorption, weather conditions and plaster coat thickness) until initial plaster setting takes place. The works can be resumed when the plaster has set enough that it becomes “dusty” when skimming with the darby is continued, and too fresh material is not “torn” out of the surface. When resuming the work too late, the plaster will have set too much which will make it difficult to work, require more work and might make it impossible to achieve the right finish. In the second stage, smooth out the surface carefully cutting off the excess of plaster with a trapezoidal darby. Then, spray the smoothed surface with water and trowel with an EPS float or, if hard enough, with a rough sponge. To achieve fine structure finish the plaster with a dry float with fine and soft sponge or felt lining. Use a power trowel to get an ideally smooth and even finish.

Tools
Plaster unit, power trowel, floats and darbies, trowel, bubble level, container for mortar.

Working conditions
Work in ambient temperatures between +5°C and +25°C. Do not add any other agents. Protect fresh plasterwork from excessive drying and moisture. Do not use electrical heaters (risk of shrinkage cracking) and gas heaters (shrinkage and carbonation processes).

Storage
Store in original, unopened packages in dry place – shelf life 12 months from production date. Protect from moisture during transport and storage.

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

General recommendations
Work according to building practice, observing health & safety standards and regulations.

* for machine-application – establish experimentally for each type of a plaster unit

Declaration of performance has been issued for the product.
Reference document: EN 998-1.
The product has been approved by the National Institute of Hygiene (PZH).
Water-soluble chromium (VI) content below 2 ppm.
Fidor, 2020-10-08. The present product sheet is valid and supersedes all previous issues.