9.2 Buried pipework
9.2.1 Internal environment
9.2.1.1 Pipework that is buried in a solid floor or wall shall be factory sheathed, or protected on site by wrapping or with suitable bituminous paint protection.
The entire section of pipe and fittings to be buried shall be protected. Any sheathing or wrapping shall be examined for cuts or other defects and made good prior to use. Joints and fittings shall be cleaned, and wrapped or painted with bituminous paint after the satisfactory completion of a gas tightness test.
Galvanized or painted pipes shall not be buried without additional protection as specified in the previous paragraph.
COMMENTARY AND RECOMMENDATIONS ON 9.2.1.1
Protective measures are applied as a precaution against electrolytic and/or chemical corrosion. The use of factory bonded wrapping or sheathing is recommended.
9.2.1.2 Where installation pipes are to be buried in magnesium-oxy-chloride cement or magnesite flooring, they shall be of copper with a factory bonded sheath and jointed with copper capillary fittings.
Bends and joints shall be further protected by wrapping with a suitable plastic tape. All surfaces shall be clean and dry before the additional protection is applied with a minimum 50 % overlap to provide at least a layer of double thickness.