Page 85 - B8773-AEW-XX-XX-PP-A-0001_[P4]_Contractors Manual

D R A F T

4.5.2 Cold Water 4.5.5 Best Practice Guidance
• Cold water installation shall commence from The water supply is to be 25mm usually MDPE,
the incoming mains stop-cock in the position unless the site is contaminated and then barrier
indicated on. pipe would be required
• A double check valve to Water Regulations
specification shall always be installed Best Practice
adjacent to the main incoming stop tap. • Lay 25mm blue MDPE water supply pipe
• Cold water pipework shall be run in light from the store to the boundary at a minimum
gauge copper tube and installed as the depth of 750mm and a maximum depth of
domestic hot water pipework. 1300mm
• All pipework shall be insulated as the domestic • (If there is no private land then this must be
hot water pipework with the addition of an laid minimum 750mm below finished ground
integral vapour barrier (Dunlop Armourflex/ level abutting the wall, coiled and capped)
Foamflex or equivalent and approved). • Sufficient pipe must be available to enable
this to reach the water main. The highway
end must be coiled and capped
• To duct and insulated the supply where it
4.5.3 Sink Waste enters the building
Problems have arisen with lack of capacity • To fit a British Standard internal stop tap
within the drains from the triple bowl sink. The
main contractor shall size the pipework such
that there is free flow of waste water when all
three sink bowls are emptied at once, and so
that if 2 bowls are emptied at once, there is no
back flow into the third bowl.

4.5.4 Thermostatic Blending Valve

Where a thermostatic blending valve is fitted,
i.e for the knee operated whb, etc, this MUST
be installed not more than 2 metres from the
appliance which it serves, to comply with water
industry regulations.

4.5.2 - 4.5.3 - 4.5.4 - 4.5.5 Cold Water, Sink Waster and Thermostatic Blending Valve 3 February 2016