| 14342 GRANULAR BEDS AND SURROUND
Granular beds and surround shall be graded gravel approved by the Engineer with a maximum size of 20mm free from dust and organic material. The bed shall be placed to the width of the trench, 50mm below pipe and up to 150mm above the crown of pipe or as indicated in drawings.
14343 BACKFILL TO PIPE EXCAVATION FOR SERVICE PIPES
Where granular fill is not used, pipe surrounds and the fill 300mm above the pipe shall be in selected excavated material free from stones retained on 20mm sieve. The backfill above granular or selected excavated material fill and concrete surrounds shall be in excavated materials in layers not exceeding 200mm before compaction. No mechanical compactors shall be used before there is 1000mm of fill material on the pipes or there is 600mm of fill material if the pipe has concrete surrounding.
14344 Thrust blocks at branches and changes of directions where shown, shall be in C-15 concrete sizes as shown on drawings.
14345 Where pipes in buildings run exposed, supports and anchors shall be provided as detailed in drawings, ensuring that adequate precaution is taken to allow sufficient freedom for movement of pipes due to thermal variation.
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