Glass Canopy and Awning Cleaning in Vancouver

Why glass canopies get dirty in a way ordinary windows do not

A vertical window sheds water. A canopy does not. Most entrance canopies sit at a shallow slope, somewhere between two and fifteen degrees, which is enough to move water but not enough to move anything else. Every leaf, needle, seed, and grit particle that lands on the glass stays there, sitting in the thin film of standing water a shallow slope always leaves behind.

Two things follow. Organic debris sitting in standing water on a north-facing or shaded canopy grows moss and algae within a single wet season, and decaying leaf matter releases tannins that stain the glass brown. And the wall above the canopy drains onto it. Runoff off concrete, stucco, or masonry carries dissolved minerals, and when that water evaporates on the glass instead of running off, the minerals stay behind.

The underside is a separate problem with a separate cause. Warm air rising off a doorway carries whatever is in it: kitchen exhaust, cooking oil aerosol, cigarette and vape residue at the doors, diesel soot and brake dust off the street. That film condenses on the underside of the glass, which no rain ever reaches. On a restaurant entrance on Robson, Main Street, or Commercial Drive, the underside is routinely the dirtier face, and it is the one most cleaning quotes silently leave out.

Surface dirt, mineral staining, and etched glass are not the same job

A lot of disappointing canopy cleans come down to one thing: the glass was not dirty, it was stained. Loose soiling washes off. Mineral deposits sitting on the surface need an acidic treatment and dwell time. But once those deposits have been on the glass long enough, they stop sitting on top of it and start attacking it. Water leaches alkali ions out of the glass, leaving a silica-rich, roughened layer behind. At that point the haze is in the glass, not on it, and no amount of washing removes it.

The field test is simple and you can do it yourself. Wet the glass. If the haze disappears while wet and returns as it dries, the deposit is still on the surface and a proper restorative clean will take it off. If the glass stays hazy while wet and feels dry and rough under your fingertips, the surface has been etched. Etched glass is a restoration job, either a controlled cerium oxide polish (which recovers most but not all of the clarity) or a replacement decision. We tell you which one you have before you commit money to it.

What we do not do to your glass

The Glass Association of North America publishes the working standard for this, and its bulletin on proper procedures for cleaning architectural glass products is specific about the two ways glass gets wrecked during cleaning. First, blades. GANA does not condone scraping glass with blades or scrapers for routine cleaning, and razor blades should never be used on coated glass at all. Plenty of canopies carry a low-e or reflective coating on one face, and a scraper takes the coating off in a stripe you can see from the sidewalk forever. Second, sequence. Cleaning runs top down, because solution and dissolved dirt running onto glass you already finished leaves residue on the lower panels.

High-pressure washing gets added to that list on a canopy specifically. A pressure wand drives water sideways into the glazing gaskets and the sealant joint where the canopy meets the wall, and it drives grit across the glass. Soft washing (low pressure, correct chemistry, dwell time, soft agitation) gets a canopy cleaner without opening a leak path. When a contractor's answer to a mossy canopy is a 3,000 PSI wand, the moss will come off and something else will start leaking.

The parts of a canopy that are not glass

Because we work on building envelopes, we look at the canopy as an envelope element rather than a window. Four things get checked on every visit.

• The wall interface. Where the canopy meets the building there is a sealant joint or a flashing detail. That joint moves with thermal cycling and it is the single most common source of water dripping through onto an entrance. A split there is cheap to fix and expensive to ignore.
• Drainage. Many canopies have a channel, gutter, or scupper at the leading edge. Once it packs with needles and moss, water backs up, sits on the glass, and accelerates mineral staining. We clear it and flow-test it.
• Structural fittings. Spider fittings, tension rods, bolts, and brackets on a glass canopy live in the weather. On oceanfront exposure in West Vancouver and along the North Shore, salt spray corrodes stainless fixings faster than owners expect. Rust bleeding down the glass from a bolt head is a signal, not a stain.
• The glass itself. Overhead glazing is safety glass for a reason. BC Building Code Division B, Article 9.6.1.2 requires safety glass to conform to CAN/CGSB-12.1-M, "Tempered or Laminated Safety Glass," and Article 9.6.1.3 requires glass to be designed to CAN/CGSB-12.20-M or ASTM E1300. On laminated overhead glass, delamination showing as a cloudy edge, or a chip at a bolt hole, is something you want reported the moment someone is close enough to see it.

Restaurants: the grease problem, and why the canopy is downstream of the kitchen

If the entrance canopy sits anywhere near a kitchen exhaust discharge, the film on the underside is not ordinary traffic soot. It is cooking grease, and it comes back faster than anything else on the building. The honest fix is upstream: a kitchen exhaust system cleaned on schedule discharges far less. NFPA 96, the standard for ventilation control and fire protection of commercial cooking operations, sets inspection and cleaning frequencies by cooking volume, running from monthly for solid fuel down to annually for low-volume operations. A restaurant on a quarterly hood schedule and an annual canopy clean is usually fighting the wrong end of the problem.

We handle the canopy, not the hood. But when we find heavy grease on the underside of an entrance canopy, we say so, because cleaning the glass every three months forever is a worse deal than fixing what is putting the grease there.

Working over an occupied entrance in Metro Vancouver

An entrance canopy is, by definition, above a door people walk through. That changes the job from a cleaning task into work at height over the public. Where the work is done from ropes, it falls under WorkSafeBC OHS Regulation Part 11 and its fall protection requirements; ladders and elevating work platforms bring in Part 13. Either way there is a plan, there is drop protection, and the area beneath the work is controlled.

For most single-storey restaurant and retail canopies the practical method is a water-fed pole from the ground or a small lift, worked early morning before opening. For atrium glazing, second-storey canopies, and glass roofs over a strata lobby, rope access from certified roof anchors reaches the whole surface without a lift blocking the entrance all day. Where a lift needs the curb lane or the sidewalk, we handle the municipal street use permit with the city before the truck arrives.