Determine where elastomeric sealant joints belong versus mortar joints on a masonry building (expansion/control joints vs. field mortar joints)

Steps

1. Locate the building's designed movement (expansion/control) joints — typically at changes in wall height/thickness, long unbroken wall runs, and junctions between different materials — rather than assuming every joint should be mortar
2. Confirm from the original design documents or brick industry technical guidance (e.g., Brick Industry Association Technical Notes on movement joints) where expansion joints are required versus where the wall was intended to be laid solid with mortar throughout
3. Reserve elastomeric sealant for joints specifically designed to accommodate differential thermal and moisture movement (expansion joints, joints at dissimilar materials, joints spanning structural movement points) — never substitute sealant for mortar in the general wythe/field joints, which need mortar's rigidity and bond
4. Select a sealant and backer rod system sized to the anticipated joint movement, following manufacturer movement-capability ratings rather than an arbitrary sealant choice
5. Tool sealant joints to shed water and avoid a mortar-like flush finish that could trap water at the joint's edges
6. During routine repointing, identify and preserve/replace any existing designed sealant expansion joints separately from the mortar repointing scope — don't accidentally mortar over a joint that was engineered to move