Seal it or strip it? The question Portsmouth building owners keep asking
Across the industrial pockets of Portsea Island and the trading estates on the mainland side of the city, the same conversation keeps happening. A unit built somewhere between the 1960s and the 1980s, a corrugated asbestos cement roof that has gone grey and porous, and an owner trying to decide between an expensive removal and replacement or some way of keeping the roof in service. For sheets that remain sound, there is a third option the regulations fully support: encapsulation, where the roof is cleaned, repaired and sealed under controlled conditions with a coating system that locks the surface down. It is a decision worth getting right first time, because the wrong call in either direction wastes serious money: premature removal throws away a serviceable roof, while coating a failed one buys nothing but delay.
Asbestos cement on Portsmouth’s commercial stock
Portsmouth is a dense city with a long industrial and naval supply-chain history, and the buildings that served it, workshops, stores, vehicle bays and light-industrial units, were roofed in asbestos cement as a matter of routine for three decades. The marine environment has not been kind to them. Salt air accelerates surface erosion, and the freeze-thaw cycles of exposed coastal winters open up the cement matrix. Many of these roofs are weathered rather than failed: structurally intact, but absorbing water, growing moss and shedding grit into the gutters. That is precisely the condition encapsulation was developed for.
Compliance: what CAR 2012 expects from a dutyholder
If you are responsible for maintaining a non-domestic building, Regulation 4 of the Control of Asbestos Regulations 2012 makes you a dutyholder. The core obligations are straightforward:
- Take reasonable steps to find asbestos-containing materials and check their condition
- Presume materials contain asbestos unless there is strong evidence otherwise
- Keep a written record of location and condition, and keep it up to date
- Assess the risk and prepare a management plan
- Put the plan into action, monitor it and review it
Nothing in that list says remove. Sound asbestos cement that is sealed, recorded and monitored is being managed exactly as the regulations intend, usually at a fraction of the cost of stripping and replacing the roof.
Where encapsulation stops being the right answer
We would rather lose a job than coat a roof that should come off. Encapsulation is not appropriate where sheets are widely cracked, holed or brittle, where the cement has degraded to a soft, friable state, or where storm damage and structural movement have compromised the roof as a whole. It is also limited strictly to asbestos cement products. Insulation board, lagging and sprayed coatings are licensable materials, and work on them belongs with an HSE-licensed removal contractor. If our survey finds any of this on your Portsmouth building, the report will say so plainly, and we will point you towards removal rather than dress up a failing roof.
How an enquiry runs
Everything starts with a condition survey. We inspect and photograph the sheets, fixings, rooflights, gutters and supporting structure, then issue a written report: a clear yes, a no, or a list of repairs needed before coating becomes viable. We are based in the South East, so Portsmouth sits within our core working area, and we carry out coating works across England. The survey gives you two things at once: evidence for your asbestos management plan, and a costed, compliant alternative to removal where the roof has the condition to justify it. Reports are written in plain English, with photographs keyed to a roof plan so you can see exactly which sheets, fixings and rooflights are being described.
