Drone cleaning or rope access?

Cleaning the outside of a building is easy at ground level and hard everywhere else. The job is the same whatever the method: get water and cleaning solution onto the surface, loosen the dirt, rinse it away, and do that without hurting anyone, damaging the building or flooding the landscaping. The difference between methods is how the cleaning head gets up there and who is exposed to risk while it does.

For decades the answer has been people: technicians on ropes, on suspended platforms, on boom lifts or on ladders with water-fed poles. Drones add another option. A cleaning drone is usually tethered to the ground, fed water and solution through a hose from a pump and tank on a truck, and sprays the surface at low pressure while the pilot stays on the ground.

Both methods are also used for more than windows: roofs and solar panels collect moss, lichen, pollen and bird droppings; concrete, metal panels and painted cladding streak; and a building's first clean after construction has its own challenges. Neither method wins every job. The right answer depends on the building, the dirt, the finish you expect and the site around it. This page sets out how each one works so you can ask the right questions. For how DroneLink plans to offer it, see windows and facades.

A useful way to decide is to split the building. High, flat, open elevations with maintenance-level dirt suit a drone rinse. Low floors, entrances, recessed glazing and anything needing detail suit hands and poles. Elevations over busy sidewalks may suit ropes or a platform, because the drone needs the area below closed. Many buildings will end up with a mixed plan, and that is fine: the aim is a clean building at an acceptable risk, not a single method. Ask any contractor, drone or rope, to explain which elevations they would do which way and why. Ask for a written scope that names each elevation, the method, the products, the runoff plan and what the finished standard looks like, so you can compare bids fairly and check the work afterwards against what was promised.

Rope access and suspended platforms put people at height. The industry manages that well with trained technicians, two-rope systems, rescue plans and inspected anchors, and it is regulated closely: provincial occupational health and safety rules in Canada (WorkSafeBC in British Columbia, and Ontario has a dedicated window-cleaning regulation) and OSHA's walking-working surfaces rules in the United States, which set inspection and certification duties for roof anchors used for rope descent. A building without certified anchors cannot be cleaned from ropes until they are installed and certified.

Lifts keep the operator in a basket with a harness, but bring ground risks: soft landscaping, slopes, overhead wires and pedestrians.

Drones take the person off the building, which removes the fall hazard for the cleaner. They add aviation risks instead. A tethered drone must not fly over people who are not involved, so the area below must be closed. It must be flown by a certified pilot under the aviation rules for the operation, which in Canada usually means an Advanced certificate and, near tall structures, may involve sheltered operations. In some cases, spraying from a drone raises its own regulatory questions (see Canada's drone rules). Wind around tall buildings is gusty and funnelled, and it sets the practical limit on the day, often at a lower speed than the open-air forecast suggests.

Every method needs a plan for runoff. What comes off the building goes into the soil or the storm drain, and municipal bylaws and environmental rules decide what is allowed there. See safety and environment.

We do not publish prices, and nobody should quote a building without seeing it. What moves the cost is predictable.

Access and set-up is often the largest share. Rope work needs anchors inspected and rigging moved for each drop. Swing stages take time to rig and reposition. Lifts need delivery, a flat path and room to reach. A drone needs a ground station, a water supply, a hose route and an exclusion zone, and it can move between elevations quickly if the ground below allows.

Height, shape and surface area decide how many drops, set-ups or flights the job takes. Setbacks, balconies, curved glass and mixed materials all add time for every method.

Dirt and finish decide the process: a maintenance rinse is quick, heavy build-up is not. Frequency matters: a building cleaned on a regular schedule is cheaper to keep clean than one left for years, and a regular clean is also a regular look at the envelope. Many owners pair cleaning with a periodic drone inspection of the roof and facades so problems are caught while they are small.

Water and runoff: the water source, the volume used, whether runoff must be captured, and the products allowed near planting and drains. Site conditions: traffic control, sidewalk closures, permits, airspace authorizations, water source, runoff capture and working hours set by the strata or the tenants. Weather adds days to any exterior job; build a window into the schedule.