Drone Roof Survey of a Georgian Youth Charity Building in King's Cross

A youth charity in King's Cross had water coming in at the top of the building and no clear picture of why, just as it was renewing its lease. Before signing, the trustees needed to know what condition the roofs were in and what putting them right would cost. The building dates from around 1793, with two towers, steep clay tiled roofs and lead covered dormers. We flew a drone over both towers, and the charity had a full written report the next day.

The building

The property is a Georgian building of solid brick, part of the original Somers Town development laid out on land owned by Lord Somers in the 1790s. The charity has been based there for decades. The part we were asked to look at is the North and South towers: two pitched roofs in clay double roman tiles, each with three lead covered dormer windows, Georgian style timber casement windows and metal gutters.

Roofs like these are hard to inspect. The slopes are steep, the dormers sit in the middle of the tiled area, and the junctions where lead meets tile, which is where Georgian roofs usually let water in, cannot be seen from the street or from a ladder.

Why a drone, not a roofer or a scaffold

The charity's question was not "how much for a new roof?" It was "where is the water getting in, what needs doing first, and what will it cost?" With the lease renewal on the table, they needed an independent answer from someone with nothing to sell, in a form their board could rely on. We kept the instruction to the roofs, where the leaks were, to keep the cost where the charity needed it.

A drone roof survey answers that without touching the building. Our pilot, Joe Murtagh (AssocRICS), flew every slope, dormer, ridge, verge and gutter at close range on 15 September 2026. Because the person flying is a surveyor, he was reading the roof while he flew it, not just collecting footage for someone else to look at later.

What the survey found

The roofs were in fair condition overall, but with a clear pattern of defects concentrated around the dormers.

Broken, cracked and slipped tiles. Across both towers we recorded broken tiles exposing the underfelt, cracked tiles, a slipped tile beside a front dormer and cracked verge tiles. Each one is a direct route for water into the roof.

Missing lead flashing at the dormers. On the north tower, the code 4 lead flashing was missing where the dormer cheeks meet the tiled roof. That junction is the classic leak point on a roof of this age.

Temporary repairs that had become permanent. The rear dormer on the south tower had been patched with flashband and a liquid roof coating. Elsewhere, sealant had been run between the laps of the tiles. Both are signs that the roof had leaked before and been patched rather than fixed, and the report recommended lifting the tiles to find the cause.

Gutters and rainwater goods. Sections of gutter were missing on the north tower, the dormers had no gutters at all, and debris and moss had built up in the gutters and on the slopes. We also noted loose mortar bedding to the ridge tiles, wet rot to a window and dormer windows needing repair and redecoration.

What the charity received

The report set out each defect with a photograph, a severity, a risk rating and a recommendation, then grouped the work into three lists:

• Immediate repairs: replace every slipped, cracked or missing tile, open up and properly lead the dormer junction where water was getting in, and replace the temporary flashband and coating on the rear dormer with a proper roof covering.
• Medium-term works: reinstate the missing lead flashings and gutters, clear the rainwater goods, re-bed the ridge tiles, remove the moss and debris, and repair and redecorate the dormer windows.
• Monitoring: keep the external decorations in good order every three to five years, and consider adding gutters to the dormers to protect the window sills.

We estimated the total at £8,000 to £12,000 including scaffolding and access. That is a figure the charity could take to its board, and a scope it could hand to contractors for like-for-like quotes.

The outcome

The charity's board reviewed the report, accepted every recommendation and approved the work. Because they need more than one price before committing charity funds, our sister aftercare service OfferAccepted is now arranging contractor quotes against the report's scope, at no cost and with no obligation to them.

Is a drone roof survey right for your building?

It usually is when:

• water is coming in and nobody can find where from,
• the roof is steep, tall, listed or otherwise hard to reach without scaffolding,
• you are renewing or taking on a lease and need to know what the roof will cost you before you sign,
• you are a charity, school, landlord or tenant who needs an independent report to justify spending, or
• you want a prioritised scope and a cost range before you ask contractors to quote.

A drone survey is visual, not intrusive. Where a defect needs tiles lifting or a hands-on test to confirm, the report says so, as it did here at the dormer junction.

Have a roof you cannot see properly? Our drone roof surveys are flown by surveyors, cover houses, blocks and commercial buildings across London and the South-East, and are quoted before you commit. Get in touch to discuss your roof.