Two main reasons for using Lime products in building:
Lime is slightly flexible. This means that day-to-day thermal movements and longer-term settlement can be accommodated without cracking the bricks or stone.
Lime is breathable. Water and vapour can escape from the building instead of being trapped and causing damage.
Lime has many other benefits for the building and also for the environment. The Building Limes Forum website
has more information on these benefits.
The answer varies depending upon joint sizes of bricks and with stonework the face area and shape of blocks. It is essential that an estimate of the total amount of mortar required is made first.
The following rules apply:
1 cubic metre of 1:3 mortar requires:
1.4 tonne sand
300 litres water
200kg lime
For a 1:2 mortar 270kgs lime are required but slightly less sand.
Renders
One square metre of render at 20mm thickness mixed in a ratio of 1:2 will require 5.7kg lime.
Please note that these calculation only apply for the company's NHL2 or NHL3.5
