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• Features & Benefits
• Preparation
• Application
• Limitations

Features & Benefits

• For professional use only
• Uses:
  • Preparation of screeds set to light foot traffic after 2-3 hours and perfectly dry after 24 hours, for the installation of parquet and resilient flooring
  • Preparation of screeds ready to receive ceramic tiles and natural stone after only 3-4 hours
  • Patching and repairing screeds in areas subject to continuous traffic (supermarkets, hospital, airports, etc.)
  • Preparation of screeds incorporating underfloor heating systems
• Special hydraulic binder, which, when mixed with graded aggregates and water, has the extraordinary capacity to harden in just a few hours and to dry perfectly at whatever thickness within 24 hours (residual moisture less than 2% water by weight)
• Very high mechanical strength
• Ideal fast track solution allowing ceramic tiles to be installed within 3-4 hours and ready to receive resilient floor coverings such as vinyl, rubber, carpet etc within 24 hours

Preparation

• All substrates are suitable for receiving a Mapecem screed as long as they are not subject to rising damp, in which case install a suitable damp proof membrane
• For bonded screeds (from 10 mm minimum), which have therefore to be anchored, the substrate must be dry, free from cracks, resistant to compressive and tensile strength, free from dust, loose materials, paints, wax, oil, traces of gypsum
• Mapecem must be mixed carefully and quickly, with water and graded aggregates 0-8 mm in diameter or with Gravel 0-8, for a maximum of 3-4 minutes, in a mixer or batcher
• The mix must be spread and levelled in the shortest time possible within 30 minutes after mixing. Special care must be taken with the quantity of water that must be enough to form a cohesive mass so that tamping gives a flat surface without a cement film
• Mapecem, aggregates and water can be mixed:
  • In a drum mixer
  • In an ordinary concrete mixer
  • In a forced action mixer
  • Manually, with a shovel
• The Mapecem mix can be placed using an automatic pressure pump. Guidance regarding the instructions for mixing must always be closely followed
• Preparing the mix, proportions and spreading the mix are exactly the same as for floating screeds, but first it is necessary to apply a Planicrete bonding slurry onto the perfectly clean substrate

Application

• The Mapecem mix is placed onto a substrate like any ordinary concrete
• A polyethylene sheet must be laid (even over a bituminous membrane or other existing waterproofing substrate) in order to create an easily flowing layer between the Mapecem screed and the already existing substrate and at the same time to prevent any rising damp
• If the Mapecem screed is crossed by pipes, it is necessary to lay a light metal mesh (a hexagonal mesh, for instance) over the screed as a reinforcement
• Mapecem screeds are prepared using the same methods as those for ordinary sand and cement screeds: preparing levelling strips, spreading the mix and accurately compacting it and then tamping to obtain a better surface finish
• Around the perimeter of the area and around the columns etc, it is recommended to insert a 1 cm thick anti-fracture material (such as felt board, cork, polystyrene, etc.)
• If work is interrupted for more than 1 hour, it is necessary to cut the screed perpendicularly and insert pieces of rod (20-30 cm long and 3-6 mm in diameter) into the edge of the screed
• They should be inserted 20-30 cm apart to guarantee perfect bonding and to avoid cracks and differing levels
• Electronic hygrometers supply only indicative values for measuring moisture
• The residual moisture level of Mapecem screeds must absolutely be measured with a carbide hygrometer, which provides absolute values of moisture by weight
• Consumption varies depending on the thickness of the screed and the amount of Mapecem. For 350-450 kg of Mapecem per m³ of aggregates, consumption is 3.5-4.5 kg/m² per cm of thickness
• Tools are cleaned with plenty of water

Limitations

• Do not use Mapecem on substrates subject to rising damp (lay a waterproofing membrane first)
• Do not use Mapecem mixed with other cements, lime, gypsum, etc
• Do not leave Mapecem dry-mixed with aggregates (quickly add the right quantity of water and use immediately)
• Do not mix Mapecem only with fine sand (use aggregates graded from 0 to 8 mm or Gravel 0-8 for thicknesses of max 8- 9 cm)
• Do not mix Mapecem with an insufficient quantity of water (this will cause partial hydration and compromise its mechanical strength)
• Do not leave Mapecem mix in the mixer for more than 3-4 minutes
• Do not mix Mapecem with an excessive quantity of water (drying time will be lengthened)
• Since Mapecem screeds are very compact, absorption of the water contained in water dispersion adhesives is slow: it is therefore recommended to use Lignobond, Ultrabond P990 1K or Ultrabond P902 2K (polyurethane adhesives) for installing parquet floors that are particularly sensitive to moisture
• Do not add water to a prepared mix and do not remix Mapecem after it has started to set
• Do not wet the surface of a screed laid with Mapecem
• Do not mix in batching plants and do not transport the mixture by cement mixer lorry: the setting time of Mapecem is too short!