Stoke-on-Trent carries an unusual mix of buildings for one city: works and warehouses left over from its manufacturing past, spread across six towns, alongside some of the largest modern distribution sheds in the country. Different eras, same roofing detail. Profiled coated steel, cut to length, lapped and screwed down, with bare metal hiding at every cut edge. That detail is where most of these roofs eventually start to fail.
The weak point built into every coated sheet
The protective finish on a steel roof sheet is applied to the coil at the factory, before cutting. Slice the sheet to length and you expose raw steel at both ends and along the laps. Rain gets drawn into the overlaps and sits against that raw edge, rust takes hold, and then it does the damaging part: it creeps underneath the coating, lifting it off the metal a little further each season. From the ground this looks like a tidemark of brown at the gutter line. Inside the lap, the coating may already be detached over a much wider band. Eventually the steel perforates and the first anyone hears of it is water on the floor.
Small now or large later: the cost logic
Cut edge corrosion is one of the few roofing defects where early action changes the bill by an order of magnitude rather than a margin. Treated at the staining stage, it is a clean-back, stabilise and seal operation on the affected edges. Ignored, it converts itself into sheet replacement, internal repairs and disruption to whatever the building does for a living. Acting early avoids:
- Replacement of perforated or delaminated sheets
- Water damage to stock, plant and ceilings below
- Emergency call-outs at the least convenient moment
- Paying for roof access twice over within a few years
- Disputes with insurers over a known, unaddressed defect
What a survey tells you that a quote cannot
Anyone can put a number on a roof from a photograph; the number just will not survive contact with the laps. We work survey-first. That means getting onto the roof, opening representative overlaps, checking sheet ends, fixings and gutters, and photographing what is actually there. On the older industrial stock around Stoke-on-Trent, roofs have often been repaired piecemeal over decades, so condition can vary sharply from one slope to the next. The survey maps that variation and the recommendation follows the evidence, which sometimes means less work than the owner feared and sometimes more.
When we would tell you not to spend the money
Edge treatment has a limit, and pretending otherwise is how buildings end up with expensive coatings over failing steel. If sheets are already holed, if the coating is releasing across the body of the sheets and not just the edges, or if corrosion has eaten into the metal’s thickness, treatment will not give you a result worth paying for. Our survey will say that in plain terms and recommend replacement of the affected areas instead, even though that is not work we carry out. Frequently the truthful position is partial: most of a roof in treatable condition, a strip or a slope beyond saving. We scope to that reality rather than to a rounder, easier story.
The natural next step: coating the whole roof
A roof old enough to have corroding cut edges is usually old enough to have a tired finish everywhere else, faded and chalking even where the steel is sound. Pairing edge treatment with a full roof coating turns two future projects into one, puts a single consistent system across the whole roof, and means the access costs are paid once. We are based in the South East and carry out edge treatment and roof coating across England, with Stoke-on-Trent firmly inside our working range. If your sheet ends are staining, or a leak has already shown up, ask for the survey before the weather makes the decision for you.
