Roof moss removal inVancouver, BC

No. We take the moss off by hand and use water only at low pressure, roughly the force of a garden hose. Pressure washing an asphalt shingle roof blasts off the protective granules that give the shingle its lifespan and UV resistance, and it can drive water up under the courses. On cedar shake, high pressure gouges the wood fibre and opens it up to faster rot. The moss might look gone the same day, but you have traded a maintenance problem for permanent damage. We also do not chemically soft wash, because those solutions end up in your garden and in the storm drain. Working by hand is slower, and it is the reason the result holds without costing you roof life.

Most single family homes in Vancouver take between three hours and a full day. A simple gable roof with light moss can be done in a morning. A cut-up roof with dormers, valleys and a thick moss mat that needs manual lifting will take the whole day, sometimes longer. Steep pitch and third storey access slow things down as well, because safety setup takes real time. Devin gives you a time estimate during the free on-site assessment, so you know before you book whether you are looking at a half day or a full one.

On most Metro Vancouver roofs, two to four years before it needs looking at again. The range is that wide because tree cover and sun exposure drive it almost entirely. A north slope under cedars in North Vancouver will move faster than an open lot in South Surrey with afternoon sun. What shortens it more than anything else is a job that only cleared the visibly green sections, because the growth that is still establishing is invisible from the ground and it is exactly what fills the roof back in by spring. Devin will give you a realistic interval for your specific roof at the assessment rather than a number that sounds good.

Most of it, and the difference is obvious the same day. The thick mats come off by hand immediately. What is left behind is the fine, tight growth bonded down into the granule layer, and that weathers off gradually over the following weeks as Vancouver rain works on the loosened surface. Taking that last layer off on the day would mean either aggressive scraping or high pressure, and both of those shorten the life of your roof. Anyone promising a perfectly uniform roof by the end of the same afternoon is doing one of the two.

Two windows work well. Late summer through to early October, before the rainy season sets in around mid-October, is ideal because you go into the wet months with a clean roof. Spring, once the heaviest rain has passed, is the other good window. That said, we work on roofs year round in Metro Vancouver and the work holds up fine in cooler weather. The one thing we avoid is working during heavy rain or high wind, for safety and because a wet roof is harder to clear properly.

It is damaging. Moss grows under the lower edge of shingles and physically lifts them, which creates a gap that wind-driven rain can get into. It also acts like a sponge, holding moisture against the roof deck long after the rain stops. In Metro Vancouver, where roofs stay damp for months at a time, that constant saturation rots sheathing and accelerates shingle breakdown. On cedar shake it causes cupping and rot. A roof with a few years of moss on it is losing life every winter it stays that way.