Materials

• Materials
  • Cast iron
  • • 1.8m – standard length
    • Lengths of pipe are joined by Yarning and Caulking (except rainwater down-pipes)
    • Centrifugal cast pipes fixed using Holderbat Clips
  • Plastic
    • Polypropylene (withstand high temp. ; no solvent; used for traps)
      • is a thermoplastic polymer
      • Melting point - 130–171 °C
      • Degrades from UV radiation (sun light)
      • For external applications, UV-absorbing additives must be used
      • Invented by the German chemist Karl Rehn in March 1954
      • Polypropylene is recyclable and has the number "5" as its resin identification code
    • Polyvinyl chloride (PVC or uPVC; brittle when cold)
    • Acrylonitrile butadiene styrene (ABS; stronger when cold; withstand high temp. for long)
    • Polyethylene (no solvent)
  • Borosilicate Glass – used in laboratories; minimal thermal expansion
     
• Copper Tube sanitary pipework can be joined by Bronze Welding
• McGuires Rule – formula to work out the correct fall of drain pipe
  • 100mm diameter pipe when laid to a gradient of 1 in 40 will give a discharge of approximately 1.14 metres per second, when flowing at 1/3 full
• The MIN  Stack Vent size on 110mm PVSS to a two-storey dwelling is 75mm

Discharging

• Brunch Pipe SHOULD NOT discharge into open hoppers
  • Any pipe CAN discharge into:
    • Stub Stack / Discharge Stack
    • Directly to a drain
  • Waste water pipe CAN discharge to a gully
    • Brunch pipe SHOULD terminate between the grating and top of the water seal
• Direct Connection to a Drain:
  • WCs Brunch Pipe on the ground floor SHOULD only be connected to a drain if the MAX depth from the floor to the drain is 1.3m
• 100mm branch connection to a discharge stack MUST have MIN bend radius of 50mm

Stack Vent

• can be reduced down to 75mm in houses of 2 stores or less
• MIN 900mm termination above the opening if <3m from it

Intumescent Fire Collar

• (~£10) – prevents spread of fire
• MIN 450mm from the invert to the lowest brunch connection
• MIN 200mm invert bend Ø
• No brunches within 750mm of the offset
• Strap-on boss connection to soil stack makes by hole saw
   

Branch Connections

• MIN 500mm between bath/shower and basin connection which is fitted with Resealing Trap

Main Stack

• MIN 75mm (82mm actual pipe size) to connect WC<80mm (only 1 WC) and for a drainage pipe
• MIN 100mm (110mm actual pipe size) to connect WC>80mm or those discharging soil waste