Mapei Topcem is a special fast drying, normal setting cement for the preparation of shrinkage controlled screeds. For the formation of bonded, unbonded, floating and heated screeds on new or existing substrates. Suitable for interior and exterior use, TOPCEM mixed with suitably graded aggregates and water, hardens within 24 hours, shortening project times significantly. Install ceramic tiles after just 24 hours. Install stone materials after just 2 days. Install resilient and wood materials after only 4 days.


Key Features

• Cement Replacement
• Cement replacement to produce fast drying screed
• Internal and external use
• Reduces construction time waiting for screeds to dry

Recommended Systems
Unbonded Screeds (min 35mm thick)
Preparing the mix. Carefully mix the Topcem with graded aggregates 0/4 or 0/8mm in diameter and water, in a mixer or screed pump for at least 5 minutes. The mix must be spread, tamped and levelled in the shortest possible time and in any event not more than an hour after preparation. Particular care must be taken with the quantity of water which must be such as to obtain a mix with a ''damp earth'' consistency that under a float finish will compact to produce a closed and smooth surface without water bleed.

Bonded Screeds (Min 10mm thick).
Preparing the mix, proportions and spreading the mix are exactly the same as for unbonded screeds, but first apply a Planicrete bonding slurry onto the perfectly clean substrate. To ensure adhesion, spread the slurry onto the surface to be covered immediately before the Topcem screed (fresh screed on fresh slurry). Note: For thicker section bonded screeds over 50mm use Eporip Epoxy Bonding Agent.

Floating Screeds (min 55mm thick)
The screed mix is prepared and applied in the same way as an unbonded screed. Mapefibre NS12 may be added to the screed at 120g/Bag of Topcem as an additional measure. The insulation should have a high resistance to compression and not depress more then 3mm under the anticipated final load. Where under floor heating pipes are incorporated, they should be located a minimum of 25mm below the surface of the screed. Additionally reinforcing mesh if used , should be placed over the pipes. The under floor heating may be commissioned after 4 days. Note: For under floor heating systems the screed must contain either additional reinforcing mesh or Mapefibre NS12 fibres.

Consumption
1.7kg/m² per mm of thickness.

Technical Characteristics
Topcem is a special hydraulic binder which when mixed with graded aggregates and water can produce an early drying high strength screed ready to receive floor finishes between 24hrs and 4 days. Topcem is defined with BS8204 1 section 5 1 3 Part F.