Roof replacement in The Blue Mountains

Code minimums for ice and water shield are written for the province, not for the escarpment. On a Blue Mountains re-roof the membrane should run substantially further up the slope than the minimum, because the minimum assumes an ice dam of a size that this snow belt regularly exceeds. Getting that wrong is invisible for years and then expensive in one bad February.

Valleys get full membrane, and on chalets with large upper catchments feeding a single valley we will often widen the open metal rather than close-cutting the shingles across it. It costs a little more and it handles the volume, which on a steep roof with a big contributing area is genuinely a lot of water moving fast.

Where an upper roof discharges onto a lower one, the lower roof needs membrane in that whole landing zone, because that is where compacted slide snow will sit for months. This is the single most common place we find water damage on chalets that were re-roofed by someone working to a generic spec.

A steep roof sheds, and everything below it is in the path. Entries, decks, hot tubs, parked cars, gas meters and the neighbour's property are all things we would rather not drop a winter's accumulation onto. Part of planning a Blue Mountains re-roof is deciding deliberately where snow is allowed to come off and where it is not.

Snow guards do not stop snow leaving the roof; they break it up so it leaves gradually rather than in one slab. Placed properly, above entries and over anything vulnerable, they solve a real safety problem. Placed badly, they create a snow-holding shelf on a roof that was designed to shed, which is its own problem. It is worth thinking about at quote stage rather than adding them after somebody's porch railing gets taken out.

A lot of chalets have cathedral ceilings, which means no attic and a very different ventilation problem. Instead of a big open space you can vent freely, you have a series of narrow rafter bays that each need their own continuous air path from soffit to ridge. If insulation was packed into those bays without a baffle, there is no path at all.

That produces condensation on the underside of the sheathing, wet insulation, and a roof deck that quietly deteriorates. A re-roof is the one realistic opportunity to fix it from above, and on cathedral roofs it sometimes means adding a vented over-roof assembly rather than trying to retrofit baffles from inside.

This is a genuine fork in the road and it affects cost meaningfully. We will tell you which situation you are in once we can see the deck, and we would rather have that conversation with the roof open and the evidence visible than sell you a number before anyone has looked.