Masonrybuilt to drain.

A masonry veneer absorbs water and holds it, so the assembly behind it needs a drainage cavity, a water-resistive barrier, through-wall flashing at the base and at every opening, and weep holes that are actually open. Block those weeps — or omit the flashing — and the water has nowhere to go but into the wall behind. This is the single most common reason a stone or brick elevation causes interior damage while looking perfectly sound from the street.

On repointing: the mortar has to be softer than the brick. Repointing a soft historic brick with a hard modern Portland mortar traps moisture in the brick face and spalls it, destroying the very thing being repaired — and it is irreversible. We match mortar to the masonry rather than to habit, cut joints to the right depth rather than skimming over the face, and match the original joint profile. Chimneys get their own attention: crown, counter-flashing and cap, which between them are the source of most chimney leaks.