Flat Roof Surveys & Condition Reports

Scope

What a proper survey covers

Water rarely enters a flat roof through the middle of the membrane. It enters at the edges of things: laps, upstands, flashings, kerbs, penetrations and outlets. A survey earns its fee by working through all of them in order, then reaching for instruments where looking is not enough.

• The field. The open expanse of covering: splits, blisters, hairline cracking, impact damage, old patches and any sign that the material has moved or aged unevenly across the roof.
• The details. Upstands, flashings, edge trims, rooflight kerbs and every penetration, judged on height, condition and how they were formed in the first place. Roofs fail here far more often than they fail in the middle.
• The drainage. Outlets, gutters and falls, plus the tide marks that show where water sits after rain instead of leaving.
• Moisture readings. Instrument checks through the build-up, because whether water has already got beneath the covering is the one question no amount of looking can answer.
• Core samples, where they are justified. A small opening cut and made good the same visit, taken when the readings say the insulation has to be seen rather than assumed. Never routine, and never left open. On an older build-up the asbestos position is settled first, from the duty holder's register on a managed building and from a laboratory wherever there is doubt, because bituminous products of a certain age can contain it.
• Inside the building. Staining, damp patches and the rooms under any suspected leak, because water travels along the structure long before it shows on a ceiling.

From the air

Drone imaging where it genuinely helps

We can bring aerial imaging into a survey, where the Civil Aviation Authority's rules and the airspace over your building allow a flight and it is flown under the registration those rules require. Where they do not allow one, the report says so and the roof is inspected the ordinary way. There are roofs where a flight changes what the report can show: large industrial and warehouse fields that would take a long time to walk methodically, fragile coverings and rooflights that should not be trodden near, parapet tops, high-level abutments and edges no ladder reaches safely. Flown as part of the inspection, it gives an overhead record of falls, ponding patterns and debris that photographs from roof level simply cannot frame.

What it never does is stand in for the inspection itself. A camera cannot lift a lap to test adhesion, press a soft area to feel what is under it, or take a moisture reading through a build-up, and those are the findings a refurbishment decision turns on. Aerial images sit alongside the hands-and-instruments survey in the same report, never instead of it.

The covering decides what the surveyor is looking for

A checklist applied identically to every roof misses the thing that matters, because each system announces its own end differently. Mastic asphalt hardens and gives way at the junctions rather than in the field. Single ply, TPO and EPDM usually outlive their welds, so the seams and the perimeter fixings are the evidence. Profiled metal leaks at laps, fasteners and gutter lines while the sheet itself looks sound. Felt and torch-on shows its age at the surfacing and the laps. Knowing which of those you are standing on changes the questions before it changes the recommendation.

Two kinds of roof need more than a covering inspection. Terraces and podium decks hide the waterproofing beneath a surface, so the report has to say honestly what was seen, what was inferred and what would take lifting to confirm. And where the readings say water has been in the build-up for years, the real question has moved to the deck and the joists beneath it, which is a different finding with a different price attached and is written up as one.

Reading

What is in the condition report, and the order to read it in

The report is the thing you are actually buying. Every defect appears as a photograph tied to a location on the roof, with a description of what it is, what caused it and how urgent it has become. Findings are ranked rather than listed, so the document answers the question a building owner actually has: what has to happen this season, and what can wait and be watched.

Read the ranking first and the reasoning second. The ranking turns a roof into decisions and a budget line; on a leasehold block it is also the document a Section 20 consultation stands on. The reasoning is what lets you defend those decisions to somebody who was not on the roof. That is also why the wording stays plain: a report that needs a roofer to interpret it is no use to the director, board, insurer or freeholder it usually ends up in front of.

Where the survey was commissioned to settle a bigger question, the report says so plainly. Before refurbishment it is the evidence that decides between repair and overlay or renewal. Before a maintenance programme it records the starting condition that every later visit is measured against.

Geography changes the logistics and nothing else. Inspecting a roof that sits between two leaseholds in Clapham, a single addition roof in Mitcham or Morden and inspecting an industrial roof out at Erith or Slade Green produce the same kind of document; what differs is the access equipment and how the visit gets scheduled.

Timing

Who commissions one, and when

Most surveys come from one of five situations, and they want slightly different things from the same visit.

• Buyers. The survey happens while the roof is still somebody else's, and the report has to be blunt about how much life is left, because it is about to price a negotiation.
• Owners holding a guarantee whose terms require documented inspection. Here the record itself is half the point.
• Anyone weighing refurbishment, where the survey exists to keep the decision on evidence rather than on whoever quoted most confidently.
• Owners of roofs nobody has ever looked at, which is more buildings than the industry admits. The survey ends the not knowing, and that is worth something on its own.
• Managing agents taking on a portfolio, who document what they have inherited on day one instead of discovering it one emergency at a time.

Storms add a sixth occasion to all of these: damage after severe weather is often invisible from the ground and expensive to find late, and it comes with its own reporting problem when an insurer is involved.

Dilapidations

Roof assessment for a schedule of dilapidations

A schedule of dilapidations is the list of what a tenant is said to owe at the end of a lease: the works needed to put the building back into the condition the lease requires. On a commercial building with a flat roof, the roof is very often the largest single line on that schedule, and it is also the line that is hardest for either side to check, because almost nobody arguing about it has been up there.

What an independent roof assessment does is put that line on evidence. It records the covering's actual condition and remaining life, it separates fair wear from disrepair, it distinguishes what the lease would reasonably require from what would amount to handing back a better roof than was let, and it prices the work that genuinely follows. Where an item is a matter of opinion rather than fact, it says so, because a schedule survives on the parts nobody can dispute. Being a document before it is anything else, it is priced as one: a fee confirmed ahead of the visit, credited back against any works that follow.

We can act for the landlord or for the tenant. We will not act for both on the same building, in the same dispute, at any point: a report is only worth something if the person reading it knows who it was written for. Whichever side instructs us, the report is written to be handed to a building surveyor and used, and it stands on its own if the matter goes further.

Pre-purchase

The pre-purchase roof report a surveyor has asked for

Buyers usually arrive here holding a homebuyer's or building survey with one sentence in it that has stopped everything: further investigation by a roofing specialist is recommended. That sentence is not an evasion. A general surveyor is right to decline to guess at a flat roof they could not safely get onto, and the referral is doing its job.

What we look at is the covering and every detail in it, the falls and whether water actually leaves the roof, the upstands, edges and penetrations where flat roofs give up first, moisture readings through the build-up where the construction allows it, and any evidence inside the building that water has been arriving for longer than anyone has admitted. Where the roof has been re-covered more than once, that is established too, because it changes what can be done next.

What the buyer gets is a plain answer to the three questions that actually matter before exchange: what condition it is in, roughly how long before it needs spending on, and what that spend is likely to involve. Enough to decide with, or to negotiate with, in writing and in time. The fee is agreed before the visit is booked, because a purchase has a timetable and surprises on the invoice are not welcome in the middle of one.

Afterwards

What the report is worth afterwards

A survey is not a one-day document. It becomes the roof's baseline: later visits are compared with it, a maintenance schedule is built on it, and if a guarantee claim is ever made, it is part of the evidence that the roof was looked after rather than abandoned. It also stays with the building when the people change, which is why we write it to be readable by whoever inherits it, not just by whoever ordered it.