This is the decision with the biggest price difference on a house roof, and it gets made wrong in both directions. People replace roofs that had twenty years left, and people repoint roofs that needed replacing and then pay for it again.
What the two jobs actually are
Re-bedding and repointing is work on the ridges and hips only. The capping tiles are lifted, the old mortar bedding is removed, they are re-bedded on fresh mortar and then pointed with a flexible compound. The tiles across the roof field are not touched except to replace individual broken ones. Replacement means stripping the covering off, inspecting and usually replacing battens, installing sarking, and laying a new roof in terracotta, concrete or metal.
Why the mortar fails long before the tile
The bedding mortar under a ridge cap is doing a structural job while being exposed to a century of thermal movement. Tiles expand and contract every day; the mortar between them cracks, admits water, and eventually turns to powder. Terracotta tile can last a hundred years. The mortar holding its ridge on does not, which is why so many Federation roofs across Stanmore, Haberfield and Marrickville have perfectly serviceable tiles above a completely failed ridge line.
Crumbling ridge mortar with sound tiles is the most common tile roof condition in the Inner West, and it is a repoint, not a re-roof. Anyone quoting a full replacement for that should be asked to explain why.
Signs it is a repoint
- Mortar visibly crumbling or missing along ridges and hips, with tiles either side sitting flat and sound.
- A handful of cracked or slipped tiles that can be individually replaced.
- Leaks that trace back to the ridge line or to a valley rather than to the field of the roof.
- Surface chalking on concrete tile with the tile body still hard and intact. That is coating wear, not structural failure.
Signs it is genuinely a replacement
- Tiles that are delaminating, flaking apart, or breaking when walked on. The tile body itself has gone, and there is nothing to repoint onto.
- Battens that are rotten or insect-damaged, which is a structural problem no surface work addresses.
- Widespread sagging in the roof plane, indicating the framing has moved.
- No sarking and a history of repeat leaks across different parts of the roof, rather than one recurring point.
- A repair bill approaching a meaningful share of replacement cost, with more of the same expected within a few years.
Getting a straight answer
None of this can be judged from a driveway, and it cannot be judged from a photograph of the worst corner either. The assessment that matters is someone on the roof looking at the ridge mortar, the condition of individual tiles, and the battens and sarking from inside the roof space. If a quote for full replacement arrives without anyone having been in the roof space, it is worth asking what it was based on.
