General requirements

03144 Finish to concrete surfaces

Concrete surfaces where formwork is in contact with the face of concrete shall be finished as required in the formwork section of this Specification.

Where no formwork is in contact with the concrete surface, the surface shall be finished in either of the following ways as indicated in the drawings or directed by the Engineer.
Trowel finish to be applied to slab surfaces exposed to view and surfaces to be covered with resilient flooring, carpeting, paint or other thin floor coating. Trowel finish shall be done using power driven trowel. The final trowel shall be hand made and left free from trowel marks. The surface plane tolerance shall not exceed 3mm in 3 meters height. Surface defects which would telegraph thorough applied flooring shall be ground off.
Floating shall be machine or hand operated depending upon the convenience of the area to be floated. High area shall be cut and low areas filled and the surface floated to produce a smooth, uniform feature.
Where non-slip brown finish is to be applied, the concrete surface shall be slightly roughened immediately after trowel finish by brooming in the direction perpendicular to the main traffic using a fiber bristle broom.
Where scratch finish is to be applied, the concrete surface shall, after leveling be scratched using stiff broom or brush for surfaces to receive bond applied cement based finish material.
Where bust hammer finish is to be applied, the concrete surface shall be pooled with a power driver hammer or manually to expose aggregate as directed. Care shall be taken to preserve arises. The surface shall be wire brushed and washed down on completion.

3145.