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 End to end by lapping the two pieces one full mesh (measured from the ends of the longitudi- nal wires in the other piece) and securing the two pieces together with wire ties placed at in- tervals of about 450 mm. 

 Side by side by placing the two selvage wires (the longitudinal wires at the edges of the fab- ric) one alongside and lapping the other, and by securing the two pieces together with wire ties placed at intervals of about 900 mm. 

## 6.2.7 Fixing of reinforcement 

All reinforcement steel shall be accurately placed and fixed in position and retained in that position during the placing of the concrete. 

Spacer blocks for holding the reinforcement from contact with the forms, or adjacent reinforcement, shall be of dense precast concrete blocks of approved shapes and dimensions. The blocks shall be fit- ted with a semi-circular hollowing and double bent poured-in binding wires. The water tightness of these blocks must be at least similar to the concrete into which they are concreted. The use of pebbles, pieces of broken stone or brick or other materials shall not be permitted. Steel shall be bound and tied in its correct position using steel wire. Apart from any other requirement, the reinforcing steel shall be fixed in such a manner that it shall support its own weight and any loads which may be imposed upon it during construction without displacement, deflection or movement of any kind. 

In slabs provided with two or more layers of reinforcement, the parallel layers of steel bars shall be supported in position by the use of steel chairs. Spacer blocks shall be placed at each chair to support the layers of reinforcement from the blinding concrete or shuttering. 

The concrete cover to the nearest reinforcement exclusive of plaster or other decorative finish and concrete blinding shall be accordance with TS 500 unless otherwise stated in the herewith Employer’s Requirements for the relevant structure. 

The distance between any two parallel bars except at laps shall not be less than 5 mm greater than the nominal aggregate size. 

All reinforcement exposed to the weather for long periods before concreting is commenced shall be covered with polythene binding tape, cement grout or other materials to the surrounding concrete. Should rust staining occur on any permanently visible surfaces, it shall be removed at once to the satis- faction of the Engineer. 

## 6.2.8 Thickness of cover 

The thickness of cover for the reinforced concrete shall be as described below: 

 For manhole elements (walls, covers, bottom slabs) 50 mm 

 For external works, water retaining structures and casting of concrete in/under water: 50 mm. 

Structures other than water retaining structures: 

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## 6.2.9 Tolerances 

Tolerances in placing reinforcement shall be: 

