mortar

Hi,

It varies with the application. A common all round mix is 1:1:6. A weak mortar for laying, say, sandstone blocks in the garden, would be 1:3 or 1:4 lime:sand with 10% cement. A strong mortar for use in a brick retaining wall would be 1:3 or 1:4 cement:sand with 10% mortar.

Cheers

what is the purpose of adding lime to a mortar mix? why not just use sand and cement?

Originally Posted by GeoffW1

Hi,

A strong mortar for use in a brick retaining wall would be 1:3 or 1:4 cement:sand with 10% mortar.

Cheers

This of course should be 10% LIME.

For some, the use of lime has been superseded by additives such as Bycol.

Lime increases workability of the mortar, lengthens the time of water retention in the mix, which allows more complete curing, and increases flexibility of the mortar, which is important where movement is anticipated.

It does however weaken the mortar, which may or may not be desirable, depending on its purpose.

Cheers

A brochure for hydrated lime might assist:

http://www.cockburncement.com.au/pro...20Brochure.pdf