What Is Roof Repointing? (And Why Perth's Older Tile Roofs All Need It Eventually)
If you own a tile roof in Perth long enough, "repointing" is a word you'll eventually hear — usually from a roofer, sometimes from a building inspector, occasionally from a neighbour who just paid for it. Here's what it actually means, in plain English, and why the tile roofs of Perth's south-east all seem to need it sooner or later.
The thirty-second anatomy lesson
Run your eye along the very top of a tile roof and you'll see a row of curved caps — that's the ridge capping, and more of it runs down the sloping hips at the corners. Those caps aren't clipped on. They're held by two layers of mortar:
Bedding
The thick mortar bed the caps physically sit on. It's the structure.
Pointing
The finishing layer sealed over the bedding's surface. It's the weatherproofing — the layer that keeps rain, wind and wasps out of the join.
When roofers talk about repointing, they mean renewing that outer seal.
Why pointing fails in Perth
The original pointing on most local roofs is rigid, cement-based mortar — and rigid is the problem. A Perth roof bakes past 60 degrees on a summer afternoon and cools right down overnight, expanding and contracting a fraction with every cycle. Rigid mortar doesn't flex; it cracks. Multiply by thirty or forty years of summers and winter fronts, and the pointing on homes across Thornlie, Gosnells, Maddington and Kenwick is now crumbling on schedule. It isn't a defect. It's just time.
Once the seal cracks, water tracks into the roof at its highest point, wind gets under the caps, and the slow leaks start.
What modern repointing involves
The good news: the fix is better than the original. Repointing today uses a flexible pointing compound — a polymer-modified material that grips hard but keeps enough give to move with the roof's daily expansion instead of cracking against it. It comes colour-matched, so the finished ridges suit your roof rather than announcing themselves.
The job itself, done properly, looks like this: every ridge and hip inspected and photographed; the old cracked pointing raked out rather than smothered; surfaces cleaned so the new compound bonds; flexible pointing applied along every cap; and photos of the finished work handed over. On most homes it's a single day's work, and the roofline afterwards looks crisp in a way you'll notice from the street.
Repointing vs rebedding — an honest note
They get mentioned together, and they're not the same job. Pointing is the seal; bedding is the mortar the caps sit on. If your caps are still solid and only the seal has failed — which is the common case — repointing is the fix. But if caps are loose or rocking when pushed, the bedding underneath has failed, and no amount of new pointing over the top will hold. That's a bigger job, and we'll tell you straight at the inspection if it's what your roof needs, rather than sealing over a problem that will crack again within a couple of winters.
Repointing vs "full restoration"
If a salesman has quoted you a full roof restoration — clean, repoint, spray-coat, the lot — it's worth knowing that when your tiles themselves are sound, repointing plus a few honest repairs delivers the watertightness for a fraction of the price. Restorations have their place; they're just recommended a lot more often than they're needed.
How do you know it's time?
Cracked or powdery mortar visible from the street, grit in the gutters, gaps under the caps, moss along the ridge line, or stains high on ceilings after rain. We've covered all five signs in detail in this guide — and if your place was built before the 1990s and has never been repointed, it's genuinely just a matter of when.
Get an honest look
We'll inspect your ridges, show you photos of exactly what's up there, and quote it free — no pressure, from Thornlie and Gosnells to Canning Vale and Armadale. Call 0493616136
