Old mortar is cut or raked out to a depth of roughly two to two and a half times the joint width, the joint is cleaned and dampened, and new mortar is packed in layers and tooled to match. The new mortar should be weaker and more permeable than the brick or stone so the joint, not the masonry unit, takes movement and lets moisture out. Hard portland mortar in soft historic brick causes spalling.
Repointing on the parapet is going down to 3/4 inch, and match the lime mortar, no straight portland.
Mortar for repointing must be softer than the masonry units; hard portland mortar in soft brick drives the damage into the brick.
Also heard as
- pointing
- repoint
Related terms
Tuckpointing
Common trade name for repointing brick, though strictly it is a decorative technique with a contrasting thin joint line.
Rake-out
Cutting and clearing old sealant or mortar out of a joint so it can be refilled.
Spalling
Concrete, brick or stone breaking off in flakes or chunks at the surface.
Efflorescence
White crystalline salt deposits left on masonry or concrete as water moving through it evaporates.