WHEN TO USE WHAT GRADE OF MASONRY MORTAR?

From durability point of view, the grade of masonry mortar to be used for a given work is primarily dependent upon the following two factors.

  • Loading condition
  • Exposure condition
masonry mortar
masonry mortar

Considering the above two factors the suitable grade of masonry mortar to be used for different works is given in the following table. Generally cement mortar is used for most of the cases, therefore corresponding to the grade, proportion of cement mortar (i.e. cement to sand ratio) is also shown in the below table for a quick reference.

Type of Work vs Grade of Masonry

Type of Work Grade of Masonry Mortar Corresponding Cement : Sand ratio
Masonry exposed to rain but protected by plaster MM 0.7 (minimum),

MM 2 (preferable)

1.:8 to 1:7
Masonry exposed to rain but not protected by plaster MM 2 (minimum) 1:7
Load bearing wall MM 0.5 (minimum),

MM 0.7 (preferable)

1:8
For foundation work laid below damp proof course

(Soil having little moisture)

MM 0.7 (minimum) 1:8
For foundation work laid below damp proof course

(Very damp soil)

MM 0.7 (minimum),

MM 2 (preferable)

1:8 to 1:7
For foundation work laid below damp proof course

(Saturated soil)

MM 2 (minimum)

MM 3 (preferable)

1:7 to 1:6
Building subject to vibration of machine MM 3 (minimum) 1:6
For parapet wall (where height is greater than thrice the thickness) MM 3 (minimum) 1:6
For parapet wall (where height is less than thrice the thickness) As used in the wall  
Bedding joints with large concrete block MM 3 (minimum) 1:6

 

Add a Comment

Your email address will not be published. Required fields are marked *