Every managing agent has had the conversation. A leaseholder reports water coming through a top-floor ceiling. The roofer says he cannot tell without getting up there. Getting up there means a scaffold tower or a cherry picker, and suddenly the cost of finding out what is wrong is larger than the likely repair. So the decision gets deferred, the leak continues, and the eventual bill includes a ceiling and a redecoration that were avoidable.
This article sets out what the different ways of seeing a roof actually cost, what each can tell you, and how to choose.
The four ways to see a roof
Ladder. Cheapest, and limited to the eaves, gutters and the first metre or two of a slope. Fine for clearing a gutter, useless for a chimney stack or a rear slope, and increasingly restricted by working-at-height rules for anything beyond a quick look.
Cherry picker or scissor lift. Hire is typically a few hundred pounds a day for a machine that reaches a two- or three-storey block, plus delivery, an operator if you do not have a trained one, and often a permit if it needs to stand on the highway. It needs a hard, level standing and enough room to swing. Rear elevations of terraces and blocks with tight courtyards are frequently out of reach.
Scaffold. The only option that lets a tradesperson work on the roof for any length of time, and the most expensive by a distance. A tower to inspect one elevation of a small block commonly runs to four figures once erection, hire period and dismantling are included; a full wrap for a larger block is much more. It also takes days to arrange and needs licences on the public highway.
Drone. A single-property survey is widely advertised in the UK between roughly £190 and £350, and at estate scale, where a pilot can fly ten to thirty roofs in a day, the per-roof cost falls considerably. It needs no standing, no permits for the building itself, and captures every slope, chimney and gutter run in well under an hour. It produces photographs rather than a hands-on assessment, and it cannot fly in high wind or rain.
What each method can actually tell you
| Question | Ladder | Cherry picker | Scaffold | Drone |
|---|---|---|---|---|
| Are tiles slipped or missing? | Front eaves only | Reachable slopes | Yes | Every slope |
| Is the chimney stack sound? | No | If reachable | Yes | Photographs of all faces |
| Is the flashing lifted? | No | If reachable | Yes | Photographs |
| Is the timber under a covering rotten? | No | Sometimes, by probing | Yes | No |
| Is a flat roof ponding? | No | Rarely | Yes | Yes, plan view |
| Can a repair be done at the same time? | Minor | Minor | Yes | No |
| Every property on an estate in a day? | No | No | No | Yes |
The pattern is clear. Drones are the best tool for finding out what is there and where. Scaffold is the right tool when someone needs to work on what was found. Using scaffold to find out is the expensive mistake.
Twenty to fifty roofs on one estate, flown to a standard shot list, reviewed by a named person, delivered as component rows your asset system can import.
When the cheapest option is the wrong one
There are cases where a drone survey is not the answer, and a good provider will say so.
- Intrusive investigation. If you already know a valley gutter has failed and the question is how far the rot extends into the deck, you need someone up there with a probe.
- Immediate make-safe. A slate hanging over a pavement needs a person, not a photograph. Fly it afterwards to record the rest of the roof.
- Weather. Sustained wind above the aircraft's limit or rain grounds the flight. A survey booked for a specific day in January needs a weather-hold day built in.
- Airspace. Blocks under an airport's flight restriction zone or near a prison need permissions that take time. A registered operator will check this before quoting.
What block managers use the evidence for
Three uses come up again and again.
Section 20 consultation. When qualifying works will cost any leaseholder more than £250, the statutory consultation asks leaseholders to accept a spend they cannot see the reason for. Dated photographs of every slope, with the defects marked and numbered, turn a contested notice into an explained one.
Insurance claims. After a storm, insurers want to see what the roof looked like and when. A drone survey within days of the event, compared against a baseline if one exists, is far stronger than a roofer's estimate written after the repair.
Planned maintenance. Knowing that the west slopes of four blocks were re-covered in 1998 and are now showing widespread slippage lets you budget a programme rather than fund a series of emergencies from the reserve fund.
A rule of thumb
If the question is what is the state of this roof, fly it. If the question is fix this specific thing we already know about, scaffold it. And if you are about to spend leaseholders' money, make sure the evidence exists before the notice goes out, not after the dispute starts.