What is the standard mix proportion for the cement mortar lining?

1 part cement to 2 parts sand by volume, with just enough water for the required workability for the application method (Clause 5.1).

What is the recommended lining thickness for a 500 mm diameter pipe?

5.0 mm, as specified in Table 1.

What is the minimum curing period for the mortar lining?

The lining must be kept continuously moist for a period of not less than 7 days (Clause 9.1).

Can this lining be repaired?

Yes, minor defects can be repaired by hand application of the same mortar mix, followed by proper curing (Clause 10.3).

IS 11906

: 1986

Recommendations for cement mortar lining for cast iron mild steel and ductile-iron pipes and fittings for transportation of water

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This standard provides recommendations for the in-situ or factory application of cement mortar lining to cast iron, mild steel, and ductile iron pipes and fittings used for water transportation. It covers material specifications, mix proportions, application methods (primarily centrifugal), lining thickness, curing procedures, and inspection to ensure a durable and protective internal surface.

Recommendations for cement mortar lining for cast iron mild steel and ductile-iron pipes and fittings for transportation of water

Quick Reference Values

Mortar mix proportion (Cement:Sand by volume)1:2

Minimum 7-day compressive strength of mortar17.5 N/mm²

Minimum 28-day compressive strength of mortar25.0 N/mm²

Minimum lining thickness for 100mm pipe3.0 mm

Maximum lining thickness for 2000mm pipe12.0 mm

Minimum curing period7 days

Practical Notes

The centrifugal application method is highly recommended over hand application to achieve a dense, uniform lining with better adhesion and lower permeability.

Proper and immediate curing after lining is critical to prevent shrinkage cracks and ensure the lining achieves its specified strength and durability.

Ensure the sand used is well-graded as per IS 383 and washed to remove clay, silt, and organic impurities, which can compromise the mortar quality.