Colyton tile roof repairs and repointing

Why the ridge line is the first thing we look at

Stand at the kerb in most Colyton streets and look along the ridge of the house. If the mortar line is pitted, patchy or showing dark hairline cracks, that is the roof telling you where its next leak is coming from.

Colyton was built out through the 1960s and 1970s, on flat ground south of the Great Western Highway between Oxley Park and St Clair. Single-storey brick veneer, concrete tile hip-and-valley, original bedding on a large share of them. Those roofs are now at the age where the mortar has given up long before the tiles have.

The mechanics of it

Rigid cement mortar and a tile roof expand at different rates. In the hottest part of the Sydney basin, with surface temperatures on a dark roof running far above air temperature on a summer afternoon and dropping sharply overnight, that difference is worked thousands of times. Eventually the bond breaks.

Once there is a gap, you do not need a deluge. Wind-driven rain off a Cumberland plain storm is enough to push water under the cap and onto the battens, where it runs sideways until it finds somewhere to drip.

What the fix involves

Not a smear of new pointing over old crumbling mortar — that fails with the bed underneath it. A proper job lifts the caps, removes the old bed, re-beds the caps on fresh mortar to a straight line, then points with a flexible compound designed to move with the roof instead of cracking under it.

On most Colyton roofs that is done as part of a full restoration, because by the time the mortar has gone the tile surface is usually porous and holding moss too. If only one section has failed, it is a straightforward repair.

While we are up there

Gutters on houses of this age are commonly original and rusting from the inside. Worth pricing at the same time — see gutter repair and replacement.

Free inspection

Call (02) 4705 5100 or send the details through. Nearby: Oxley Park, St Clair, St Marys and Erskine Park. All areas we cover.