Retain Existing Coverings
The existing roof can remain in place where its condition and the proposed design permit retention.
Commercial & Industrial Roofing
Commercial & Industrial Roof Overcladding
Roof overcladding solutions for warehouses, factories and industrial buildings. Install a new external roof covering over suitable existing roofing, with opportunities to improve weatherproofing and thermal performance without complete roof removal.
An Alternative to Roof Removal
What Is Roof Overcladding?
Roof overcladding involves installing a newly specified roof covering above an existing roof, with the original covering retained beneath the new construction.
A suitably designed secondary support or spacer arrangement can provide fixing points for new profiled metal sheets, with insulation incorporated where appropriate.
This can provide a practical refurbishment solution for some ageing commercial and industrial roofs, particularly where complete stripping would involve extensive disruption to activities below.
However, overcladding is not suitable for every building. Structural capacity, existing roof condition, moisture management, drainage, fire performance and future maintenance must all be assessed.
Elite Waterproofing can help clients consider overcladding alongside roof refurbishment and replacement options, with the appropriate design and specialist input established for the project.
Potential Advantages
Why Consider Roof Overcladding?
When technically appropriate, overcladding can offer an alternative to removing and replacing the complete existing roof.
Reduced Strip-Out
Retaining suitable materials may reduce removal work and the quantity of roofing waste.
Insulation Opportunities
The new roof build-up may incorporate insulation to improve thermal performance where specified.
New External Weatherproofing
A correctly detailed outer covering can provide a new weather-resistant roof surface.
Operational Planning
Some projects can be planned around building occupancy, subject to safe access and work arrangements.
Updated Appearance
New roof sheets and finishing details can improve the exterior appearance of older buildings.
Understanding the Construction
How an Overcladding System Works
The new roof covering is designed around the original roof structure, rather than simply fastening new sheets to old roofing material.
A structural assessment is needed to establish whether existing purlins, frames and other supporting components are capable of carrying the proposed additional loads.
The selected overcladding system may include engineered brackets or spacers, thermal insulation, new profiled metal sheets and redesigned roofing details.
Fixing design must transfer loads to appropriate structural elements. Existing asbestos cement sheets should not be treated as structural supports.
This is an illustrative arrangement only,
not a construction specification.
The actual system, fixing arrangement,
insulation, vapour control and
structural design must be determined
for the individual building.
Specialist Asbestos Roof Considerations
Overcladding Asbestos Cement Roofs
Some older industrial buildings have asbestos cement roofs that may be considered for overcladding. This requires careful assessment and project-specific controls.
Asbestos Identification
The existing asbestos register and relevant survey information must be reviewed. Further investigation may be required before refurbishment works begin.
Fragile Roof Materials
Asbestos cement roofing can be fragile. Work must be planned to prevent falls through roof sheets and rooflights.
Fixing & Disturbance
Any work that could disturb asbestos-containing materials requires appropriate risk assessment, competent operatives and suitable controls.
Retained Asbestos Management
Overcladding does not remove asbestos from the building. The retained materials must continue to be recorded and managed appropriately.
Overcladding is not automatically
preferable to asbestos roof removal.
The choice depends on roof condition,
structural suitability, future use
and the complete risk assessment.
Relevant guidance includes
NFRC HSGS44
and
HSE asbestos guidance
.
Commercial Metal Roofing
Overcladding Existing Metal Roofs
Existing profiled metal roofing may also be considered for overcladding where the building and original construction are suitable.
Corrosion Assessment
Existing sheets, fixings and roof structure must be assessed for corrosion and deterioration.
Load-Bearing Structure
The structure must be suitable for additional dead loads, wind actions and the proposed fixing arrangement.
Moisture Control
The new roof design must address condensation and avoid trapping unacceptable moisture within the build-up.
Project Feasibility
What Must Be Checked Before Overcladding?
An initial condition review helps identify whether overcladding is a realistic option or whether repairs or replacement should be considered instead.
Structural Loading
Assessment of supporting frames, purlins, fixings, dead loads, wind actions and any additional imposed loads.
Thermal Performance
Consideration of insulation, thermal bridges, condensation risk and vapour movement through the proposed roof.
Drainage & Gutters
New roof height and geometry may require changes to gutters, outlets, eaves, flashings and adjoining drainage.
Rooflights & Penetrations
Existing rooflights, vents, ducts and rooftop equipment must be considered as part of the design.
Fire & Building Requirements
The proposed roof build-up must meet the relevant fire performance, planning and building control requirements.
Future Maintenance
Safe access, retained materials, inspection, repairs and eventual roof removal should be considered at design stage.
Project Delivery
Our Roof Overcladding Approach
Overcladding requires coordinated roofing, structural and specification decisions before installation begins.
Initial Enquiry
Discuss building use, roof age, construction, known defects and project objectives.
Condition & Feasibility
Review the existing roof, available asbestos information, structure and potential overcladding constraints.
Proposed Specification
Establish the required structural and technical design, system, insulation, details and work programme.
Installation & Handover
Complete the agreed works with appropriate controls, inspection and records for the finished roof.
Compare Your Options
Overclad, Refurbish or Replace?
The correct solution depends on the existing building, rather than choosing a method before the roof has been assessed.
Roof Overcladding
Retain the original roof beneath a new covering where the structure, roof condition and technical design allow.
Discuss OvercladdingRoof Refurbishment
Repair and waterproof suitable existing roof coverings without installing an entirely new outer roof.
Explore RefurbishmentRoof Replacement
Remove existing coverings where retention is unsuitable or a new roof construction is required.
Explore Replacement
Operational Commercial Buildings
Working Around Your Business
One potential advantage of overcladding is the opportunity to retain the existing roof while installing a new outer covering. However, keeping the building operational is not guaranteed.
Safe Roof Access
Access equipment, fall protection and controls for fragile materials must be established before work.
Working Above Occupied Areas
Activities below the roof must be considered, including people, stock, machinery and sensitive operations.
Material Handling
Loading, lifting, roof-level storage and construction sequencing require appropriate planning.
Weather & Programme
The installation sequence must consider exposure, weather conditions and the requirement for temporary protection.
Frequently Asked Questions
Roof Overcladding FAQs
What is industrial roof overcladding?
It involves constructing a new outer roof above an existing roof covering, with the original material retained where suitable. The new system requires appropriate structural support, weatherproofing and technical design.
Can an asbestos cement roof be overclad?
Sometimes. Suitability depends on existing roof condition, structural capacity, asbestos information, fixing arrangements and safe access. Retained asbestos materials continue to require management.
Does overcladding remove asbestos?
No. An asbestos cement roof that is overclad remains within the building. Its location and condition must continue to be appropriately recorded and managed.
Can insulation be added?
Yes, some overcladding systems incorporate insulation. The design needs to account for thermal performance, condensation and vapour control.
Will the existing structure support an additional roof?
This cannot be assumed. A competent structural assessment must establish whether the proposed loads and support arrangement are acceptable.
Is overcladding cheaper than replacement?
It may be, particularly where retaining the roof reduces removal and waste-disposal work. The comparison depends on structural upgrades, insulation, access, detailing and the existing roof condition.
Can the building stay open during overcladding?
Some projects can be organised around ongoing operations, but restrictions may still be required for safety, access, material handling or weather protection.
How much does commercial roof overcladding cost?
Costs depend on roof size, existing condition, structural requirements, insulation specification, new covering, rooflights, drainage and access. A project-specific assessment is necessary.
Related Roofing Solutions
Explore Our Other Services
Request a Roof Assessment
Considering Roof Overcladding?
If your warehouse, factory or commercial building has an ageing metal or asbestos cement roof, contact Elite Waterproofing to discuss whether overcladding, refurbishment or replacement may be appropriate.
Call 01509 414300