LIME PUTTY REPOINTING
Repointing is essential to ensure the durability of a wall. Over time, wind and rain weaken the lime putty between the bricks letting water into the joints which causes damage. Using lime putty over cement mortars permits the walls to “breathe” allowing moisture to escape. When repointing old walls, lime putty is a great option as it is flexible; therefore, it is less likely to crack as walls generally move and settle and the mixture will strengthen within the next year or two reaching maximum strength and durability.
PROTECTION AGAINST THE ELEMENTS
Repointing walls stops damaging the walls which is a process of removing the old putty in the joints and replacing it with new lime putty. The first stage of repointing would be to ‘rank out’ or remove old putty from between the bricks at a depth of about 25 mm. The old putty can be removed by using a chisel and a hammer being careful not to chip of remove any of the brickwork. After ranking out old putty, the surface needs to be cleaned out using a stiff brush to brush out any loose materials that has been left in the joints. Then the joints need to be dampened which helps the lime putty to stick to the brickwork and stops it from drying out too quickly. To repoint the joints, a narrow pointing tool is needed to press the putty firmly into the joints but there should not be any putty left on the face of the brick. Lime putty does not harden as fast as cement mortars. After repointing, for the next few days the lime putty needs to be protected from any harmful elements. This is best done by gently spraying the lime putty with water. Covering the lime putty work with a damp hessian sheeting in hot weather will add extra protection and stop the putty from drying our too quickly.