(a)   All joints in the building sewers shall be made water-tight. If recommended by the City Inspector, a water pressure test shall be made on the completed sewer to ensure a compliance with this requirement, requiring that the building sewer withstand an internal water pressure of five psi, without leakage.
   (b)   Cast iron pipe with lead joints shall be firmly packed with oakum or hemp and filled with molten lead, federal specifications QQ-L-156, not less than one inch deep. Lead shall be run in one pour and caulked and packed tight. No paint, varnish or other coatings shall be permitted on the jointing material until after the joint has been tested and approved.
   (c)   All joints in vitrified clay pipe shall be the polyurethane-compression type joints, approved by the City Inspector.
   (d)   Joints for all plastic pipe used in building sewers shall be the slip type joints or solvent weld type, approved by the city.
   (e)   Joints between any two different types of pipes shall be made with lead, asphaltic jointing materials or concrete, as approved by the city. All joints shall be water-tight and constructed to ensure minimum root penetration and to the satisfaction of the city.