Method Statement for packing of toilet bores

Modern building construction methods avoid sinking of toilet floors and instead take the toilet piping system down to a lower floor immediately below the ceiling through bores cut in RCC slab to have easy access to the pipe assembly in case of emergency, repairs and maintenance. It then becomes very important to treat these bores with absolute surety against water leakage. Below are a few guidelines.

• The area around the pipe and the interface between the pipe and the slab will be thoroughly cleaned.

• A temporary chute will be placed below the pipe (around the ceiling area) akin to shuttering for concreting or packed with quick setting cement mortar to seal the gap from below.
  

• An acrylic based primer will be applied both around the pipe and the concrete core around it after pre-wetting the surface.
  

• Cementitious grout / super fluid micro concrete (which are expansive and self levelling in nature with non-shrink property) will be mixed with water in the ratio of 2.5:1 (powder: water) to form a semi liquid pourable mix.
  

• The above mix will be poured around the gap between the pipe and the slab concrete and gently agitated to ensure complete contact with the concrete and to the full depth of slab.  The grout is poured in a slightly recessed manner to leave a 15mm deep gap all around.
  

• Any air entrapment to be released by compaction and agitation.
  

• After the grout is nominally cured, an epoxy primer is applied and the gap of 15mm depth all around the pipe and the slab is filled with 3 part epoxy mortar and finished flush with the surface.
  

• Release the chute or remove the temporary shuttering/packing from below.
• Pond water around the pipe to check for leakages, if any. If found, rectify by repeating the necessary steps as above.