Mortar Mix

[staningrimsby]

Hi guys

i have searched for this answer but am unable to find it,

i am building an extention out of blockwork above dpc and engineering bricks below dpc, my architect has detailed that my outer leaf should be laid in 1:1:6 mortar.

What does this mean, i can appreciate that the 6 is sand to 1 part cement but what is the other 1 for ???

also when digging my foundations out it details the hole should be 600x225 and 1.2 mtrs deep, once again i understand the 1.2 mtrs down and the 600 wide but what is the 225mm for ???

Cheers in advance
Stan.

 

[noseall]

the 'other' 1 is probably for lime.

225mm is the minimum thickness for the concrete.

probably.

 

[staningrimsby]

thanks for that noseall,

What is the lime for ??? is it just to allow slight movement in the mortar ???

 

[Shytalkz]

It is lime. Makes the mix slightly more permeable and more responsive to thermal movement. Lightens it up a tad, too; there's nothing worse than grey joints.