Great care must be used when removing existing mortar
To prepare for repointing the existing mortar should be raked-out to a depth that is at least two times the height of the joint. For example a 10mm high joint should be cut to a depth of at least 20mm. To mitigate the potential for damaging the masonry when raking-out, the process must be undertaken with care.
Existing mortar joints can be cut-back using either chisels, rakes or grinders.
- Soft can be removed using hammer and chisel or a mortar rake. This is a long slow process and power tools are often utilised to accelerate removal rates.
- Cutting wheels are always used to remove hard pointing and also where joints are over-filled. This is minimizes the risk of damage to the brick edges, which are easily chipped when using chisels. Cutting wheels are only be used in conjunction with dust extraction equipment.
Before applying new mortar, the brickwork is washed to remove loose particles or dust remnants and the joints are dampened to ensure maximum bond with the new pointing mortar.