Mx 131 AL
Premixed mortar for selflevelling screeds
MX 131 AL is a powder cementitious product, premixed with inerts selected for their purity and grain size with the addition of specific additives which adjust the fluidity and shrinkage in order to optimize its self-levelling characteristics. MX 131 AL is ideal for self-levelling screeds, as a sub-floor layer for wooden and vinyl floors, linoleum, carpets and ceramic tiles.
USES AND APPLICATION PROCEDURE
Remove foreign matters from the floor and check that it is dry and stable. Place a 0.7-1 cm thick strip of compressible material at least as high as the screed along the perimeter walls and the vertical elements. Apply polyethylene sheets on the entire casting surface, making sure to overlap the joints by at least 25 cm and to run them up the walls by a few centimetres above the compressible strip or apply the primer. In case of floor in contact with the ground, you should waterproof the laying surface with a sheath. Check the reference levels and arrange possible sideboards to hold the casting in place. It is recommended to divide the screed near possible openings or protrusions, by placing a divider strip on it during the laying or by sectioning it once it has hardened. The maximum surface that can be created without division, similar to the traditional sand and cement-based screeds, is of around 30 m2. In case of underfloor heating systems, it is necessary to place en electro-welded mesh inside the screed, making sure to fix it to the insulating panels. Approximately, the net will have a 50x50 mm or a 50x80 mm mesh and a 2 mm thick steel rod; it should be interrupted close to the expansion joints that will be placed by the door thresholds and in any case so that the single rooms do not exceed 30 m2. For the position of joints in odd-shaped floor plans, it is necessary to follow the designer’s instructions. N.B.: to ensure a good quality of the self-levelling screed, special care must be paid to the preparation of the laying surface (no cracks, waterproofing, etc.). The self-levelling screed is mixed in a horizontal mixer and delivered to the laying surface by a continuous worm pump. The product must be laid starting from the thickest areas and then levelled with a levelling bar.
Type of mortar: Cementitious screed materials CT C20 F5 according to EN 13813.
Application thickness: from 3 to 6 cm
Maximum grain size: 5.0 mm
Theoretical yield: 17 kg/m2 for a 1 cm thickness
Pack: in 30 kg bags on pallets of 1.62 t
MAIN TECHNICAL DATA
• Mixing water: approx. 13%
• Compressive strength after 28 days: ≥ 20 N/mm2
• Specific gravity of the dry mortar: 1700 kg/m3
• Specific gravity of the fresh mortar 2000 kg/m3
• Flexural strength after 28 days: ≥ 5 N/mm2
• Reaction to fire: A1 fl
• Thermal conductivity: h = 1.17W/mK (tab. A.12 EN 1745)
• Durability (freeze/thaw cycles): NPD
• Pot life: approx. 30 min
• Ready for traffic: 24/48 hours
Supply and application of a ready to use, self-levelling premixed cementitious screed (CALCEM MX 131 AL type, produced by CALCIDRATA S.p.A.), to mix with water only, class CT C20 F5 according to UNI EN 13813.