SYSTEM SPECIFICATION EVIDENCE NOTE
The applicable product, primer, preparation method, system build-up and warranty route for any asbestos cement roof project must be confirmed from project-specific manufacturer documentation before work begins. Product suitability cannot be established from the roof material alone. The available product technical data sheets for the systems Forti Nova works with do not explicitly confirm asbestos cement as an approved substrate. No named product is presented as a default system for AC roofing on this page. A product may only be specified where the manufacturer has confirmed its suitability for the specific AC substrate condition, preparation method, asbestos controls and build-up in writing, before application proceeds.
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MANAGEMENT ROUTES FOR AC ROOFING
Asbestos cement (AC) profiled roofing remains widespread across the UK's pre-1999 commercial and industrial building stock — particularly on factories, warehouses, agricultural buildings and older retail and storage units. Where buildings remain in use, duty holders are required to manage asbestos in situ under the Control of Asbestos Regulations 2012. The management route for any specific AC roof depends on the sheet condition found at assessment, the extent and nature of any degradation or damage, the management history, the proposed programme and the long-term asset plan.
The management routes are distinct and must not be conflated:
Manage in place is appropriate where the AC material remains in suitable condition, is not being disturbed and can be safely managed without any refurbishment or coating work. Monitoring, inspection and the maintenance of the asbestos management plan are the primary obligations in this route.
Encapsulate or coat — applying a compatible liquid-applied coating over assessed and confirmed-suitable AC roofing — may be appropriate where the sheets are suitable to retain, the proposed preparation and application can be undertaken safely within the applicable asbestos management and work controls, and the manufacturer has confirmed a suitable system for the specific substrate and conditions. Encapsulation stabilises the surface, may reduce weathering-induced surface erosion and water penetration, and may extend the period before replacement is required. It does not remove asbestos, does not discharge the duty to manage the asbestos that remains, does not restore structural strength, and does not reclassify the roof as non-fragile. Encapsulation is not automatically preferable to other routes.
Local repair or sheet replacement may be appropriate for limited damaged areas — isolated fractured sheets, displaced fixings, failed laps or interfaces — where safe removal and replacement can be planned within the applicable asbestos work controls. All work involving disturbance of AC sheets must be assessed against the applicable requirements under the Control of Asbestos Regulations 2012 and relevant HSE guidance before it proceeds.
Overclad installs a new weatherproof outer skin — typically profiled metal — over the existing AC roofing. The AC remains beneath and continues to require management under the duty-to-manage framework. Overcladding does not remove asbestos and does not discharge the duty to manage it. Work involved in installing the new skin must be assessed against the applicable requirements. Fragile-roof risks remain throughout the works and must be addressed in the method statement.
Complete removal and replacement — asbestos cement sheets removed and disposed of by a contractor competent for the assessed category and scope of work, in accordance with the applicable regulations. This is appropriate where sheets are severely damaged, the roof has reached the end of its usable condition, substantial intrusive work is planned, the building programme requires strip-out regardless of sheet condition, or the duty holder has determined through the management plan process that long-term removal is the more rational route. Removal discharges the management obligation for the removed material.
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ASBESTOS CEMENT SHEETS ARE FRAGILE
AC profiled roofing sheets and any AC rooflights present on the same roof should be treated as fragile unless a competent person has confirmed otherwise. This is independent of the asbestos management obligations. Key controls include:
— Avoiding direct roof access where reasonably practicable. All survey, assessment, preparation and coating activities should be designed to minimise the need for personnel to work at or on the roof surface.
— Where access is required, suitable access systems must be provided — stagings, crawl boards or platforms spanning the structural purlins, not resting on the AC sheets themselves.
— Edge protection, fall restraint or fall arrest systems as required for the specific roof geometry and work activity.
— Safety nets below fragile areas where required by the risk assessment and method statement.
— AC rooflights must be identified before access begins. AC rooflights are fragile and must be treated accordingly — they are not always visually distinct from the surrounding AC sheets.
— Rescue planning must be in place before work commences.
— Coordination between the client, contractor, asbestos specialist and principal contractor is required to ensure that safe-access controls and asbestos management controls are jointly planned and do not conflict.
Applying a coating or encapsulant does not make the roof safe to walk on. Completed encapsulation does not restore a non-fragile classification to AC sheets.
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SURVEY AND ASBESTOS INFORMATION
No coating, encapsulation or refurbishment work on AC roofing may be specified or carried out without suitable asbestos information in place.
Existing information that may be required:
— An asbestos register, confirming the presence and location of known asbestos-containing materials.
— An asbestos management plan, setting out the strategy for managing identified materials.
— Previous survey reports covering the AC roofing, where these remain current and sufficient.
— Previous sampling or analytical results confirming the material type and condition.
— Records of any previous repairs, coatings or removal work affecting the AC sheets.
Survey types:
HSE defines two principal asbestos survey types. A management survey supports normal occupation and routine maintenance — it is designed to locate and assess the condition of asbestos-containing materials that could be disturbed during ordinary building use. A refurbishment or demolition survey may be required where the proposed work will disturb the building fabric — including preparation, fixing replacement, repair or sheet replacement. A management survey alone is not sufficient where intrusive work is proposed.
Targeted sampling or additional investigation may be needed where existing information is incomplete — for example, where the material type, extent or condition cannot be confirmed from available records.
The required scope must reflect the proposed work — not every encapsulation project requires a full refurbishment and demolition survey, but a management survey alone cannot be relied upon where intrusive preparation or repair is planned. Surveys must be undertaken by a competent surveyor. The applicable survey type and the competence required are defined by the Control of Asbestos Regulations 2012 and current HSE guidance.
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WORK CLASSIFICATION AND LICENSING
Work involving asbestos cement is classified into three categories under the Control of Asbestos Regulations 2012: non-licensed work, notifiable non-licensed work (NNLW), and licensed work.
Encapsulation or sealing of asbestos-containing material that is in good condition can normally be non-licensed work. Routine maintenance involving asbestos cement can often be non-licensed. Non-licensed does not mean uncontrolled — competent workers, suitable information, instruction and training, appropriate protective equipment and controls, correct waste handling and disposal remain necessary.
Where asbestos cement is significantly damaged, or where the proposed work method would substantially break up the sheets or disturb the surface in a way that generates higher levels of fibre release, the work may become notifiable non-licensed work. NNLW must be notified to the HSE before it commences and carries additional requirements for supervision, health records and medical surveillance.
Higher-risk work involving more hazardous asbestos materials — rather than the relatively lower-risk asbestos cement — or where asbestos cement is so damaged that the work generates significant fibre release, may require an HSE-licensed contractor.
The category applicable to each specific scope of work must be determined through the risk assessment and plan of work for that project. This page does not constitute definitive legal advice. Refer to current HSE guidance and take competent asbestos advice for the specific project.
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PREPARATION
Preparation of AC roofing is the most safety-critical stage of any coating programme. Generic roofing preparation methods — pressure washing, mechanical abrasion, grinding, sanding, scraping — must not be used on AC roofing unless the exact method has been confirmed in an approved asbestos plan of work and is compatible with current HSE guidance on the disturbance of asbestos-containing materials. Methods that generate dust or fibre release from AC surfaces require specific asbestos controls.
Preparation must be designed to minimise fibre release and will typically require controlled wet methods, suitable low-disturbance cleaning techniques, appropriate equipment specified in the plan of work, controlled debris collection, personal and respiratory protective equipment, decontamination procedures, waste handling and disposal in accordance with the applicable regulations, environmental controls, and specialist supervision by a competent person.
The applicable HSE Asbestos Essentials task guidance for cleaning, repairing and painting asbestos cement products must be followed. The plan of work must be in place before any preparation commences.
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SUBSTRATE AND STRUCTURAL CONDITION
A sheet may appear coat-able from above while still being structurally unsafe or unsuitable to retain. The assessment must consider all of the following — surface condition alone is not sufficient:
Sheet cracking, local breakage and severe weathering or surface erosion. Fixing condition — whether hook bolts, drive screws or other fixings are sound, corroded, loose or missing. Washer and cap condition. Lap condition — whether laps are open, displaced or sealed with incompatible materials. Purlin and supporting structure condition, independent of the AC sheet surface. AC rooflight condition and location. Roof deflection under load. Previous repairs and previous coatings — including identification of any silicone, bituminous or incompatible treatments. Moss, lichen and biological contamination. Evidence of water ingress and its origin. Underlying insulation, liner or concealed construction condition where present.
The surface condition, dryness at the time of application, porosity, contamination and the condition of the wider roof build-up must be assessed because these factors can affect preparation, adhesion and waterproofing performance. Where the building contains insulation, liners or concealed construction, moisture within the roof build-up must be distinguished from moisture held at the sheet surface — both matter, but require different assessment and responses.
