Roof repair in The Blue Mountains

The escarpment wrings moisture out of every westerly that crosses the bay, and The Blue Mountains takes the result. Seasonal snowfall here runs well above what Collingwood sees a few kilometres away, and the roofs were mostly built steep specifically to deal with it. That steepness solves one problem and creates others.

Snow on a steep roof does not sit still. It creeps, and as it creeps it drags on anything fastened to the roof surface: vent stacks, snow guards, skylight curbs, and the top edge of the shingle courses. A lot of the repair work we do in the Blue Mountains is fixing things that snow movement has slowly pulled loose over several winters, rather than anything a single storm did.

The other consequence is where the snow ends up. It slides, and it piles at the bottom of the slope, over entries, decks and against lower roof sections. Where an upper roof discharges onto a lower one, you get a compacted mass that sits there for months, and that is where ice and water shield either earns its keep or turns out not to have been installed far enough up.

Chalet roofs tend to be interesting shapes. Multiple gables, shed dormers, cathedral ceilings with no attic to inspect from, and long valleys that carry an enormous volume of water and snowmelt off a large catchment area. Those valleys are the single most common leak location we find here.

A valley that was closed-cut with the shingles woven across it will eventually wear through where the water concentrates, particularly on a steep pitch where velocity is high. An open metal valley lasts far longer but only if the metal is wide enough and the shingles are cut back cleanly from the centreline. We see plenty that were cut too tight, so the shingle edge sits in the water channel and wicks.

Cathedral ceilings complicate diagnosis, because there is no attic to get into and follow the water back to its source. In those cases we work from the outside in, and we will often ask to run water on the roof in a controlled way to find the entry point rather than guessing and hoping.

A twelve-in-twelve pitch is not a roof you walk. Repairs here need roof jacks, proper anchor points and fall arrest, and sometimes staging built up from the ground. That is a real cost and it is why a Blue Mountains repair quote will not match a bungalow repair quote for the same square footage of work.

It is also why we would rather look at everything while we are up there. If we are already set up on a steep roof to fix a valley, checking the ridge, the stack flashings and the upper courses costs almost nothing and can save a second mobilisation in six months. We will tell you what we find and what can wait.