Original Victorian lime pointing round here has often lasted a hundred years, so the honest range for repointing is anywhere between three years and fifty-plus. The difference isn't luck; it's how the job was done.
What good repointing should give you
- Cement repointing on brick, done properly: 30 to 50 years before it needs looking at again. The mortar is harder than the weather, and the failure point is usually the brick rather than the joint.
- Lime pointing on period brick or stone: 50 years and often longer. Lime is softer, so it takes the wear instead of the brick, and it self-heals small cracks as it slowly carbonates. It's what the wall was built with, so it moves with it.
- Chimney stacks: 20 to 30 years. Stacks catch the worst of the weather from every side and sit in the flue gases from below, so they wear faster than the walls under them.
- Patio joints: 10 to 15 years for a resin jointing compound, less for a sand-and-cement joint that gets driven over.
Why some repointing fails in a few years
Nearly every early failure we see comes down to one of three things:
- It was never raked out. Mortar smeared over the top of old joints only grips the surface. It looks fine for a summer, then frost gets behind it and it comes away in sheets. This is the most common thing we're asked to put right.
- Wrong mortar for the wall. Hard cement on soft brick or stone doesn't fail itself — it makes the brick fail. The faces spall off and water gets in behind the joints anyway. See lime or cement.
- It wasn't protected while curing. Mortar that dries too fast in sun or wind goes powdery and never reaches full strength; mortar that freezes in its first days crumbles. Both look fine on the day and fail within a couple of winters.
What shortens the life of good pointing
Exposure, mostly. A west-facing gable above Whitworth or Littleborough takes the prevailing rain full on and will wear faster than a sheltered south wall in Bamford. Leaking gutters and downpipes are the next biggest killer — a wall that's constantly wet from a blocked gutter will lose its pointing years early, and no mortar survives being frozen while soaked. Vegetation growing in the joints, and pressure-washing the wall, both do damage too.
Making it last
Have it raked out properly, in the right mortar, at the right time of year, and protected while it cures. After that, keep the gutters clear and don't let ivy get hold of it. Every job we do carries a 10-year written guarantee, which is a reasonable indicator of how long we expect it to stand — and we've walls we pointed twenty-five years ago that don't need touching yet.
