Concrete
The horizontal concrete substrate shall be in a good sound condition and free from dust, loose material, surface contamination and materials which reduce bond. Concrete surfaces shall be generally level (within tolerances) and shall not be laid to a gradient, so grout flows to the lowest end.
Pre-Wetting Substrate
Concrete surfaces shall be saturated with clean low pressure water a minimum 2 hours before application ensuring that all pores and pits are adequately wet. The surface shall not be allowed to dry before application of the grout. Remove excess water prior to application, and ensure there is no standing water on the surface. The surface shall achieve a dark matt appearance without glistening and surface pores and pits shall not contain water.
Formwork
Formwork shall be clean and fixed in place as soon as possible after the substrate has been prepared. If required, release agents shall be applied to the formwork before placing into position. Do not contaminate the substrate with the release agent and reduce bond of the grout material from spillage or run-off.
Openings in the formwork shall be protected to prevent ingress of debris or contamination. Formwork shall be watertight and free from obstructions to allow the free flow of grout. Formwork shall be designed to allow air and water bleed to escape. In the case of a long base plate, ensure there is enough pressure head to help the flow of the grout. Divide into sections if necessary and apply the grout in more than one stage.
Mixing
Mixing shall always be carried out in accordance with the recommendations contained in the latest product data sheet (PDS). Do not use water beyond the stated maximum and minimum limits. In determining the mixing ratio the wind strength, humidity, ambient and substrate temperature and shall be taken into consideration. For best results only mix full bags.
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