Independent Roof Inspection For Planned Maintenance Budegeting
Deeside, North Wales
Property Type: Large commercial premises
Inspection Type: Independent Roof Condition Survey
Roof Covering: Profile Metal Sheet
Report Length: 40 Pages / 35 Annotated Images
The Challenge
Verton Aerial Ltd was instructed to undertake a comprehensive roof condition inspection of a large commercial manufacturing facility in North Wales as part of the client's planned preventative maintenance strategy.
With valuable production equipment and controlled manufacturing areas beneath the roof, the client wanted to identify developing defects before they resulted in water ingress, operational disruption or costly emergency repairs.
The property comprised extensive profiled metal roof coverings incorporating numerous roof penetrations, including flues, ventilation systems and service pipework.
Inspection Objective
Our objective was to provide the client with an independent assessment of the roof's overall condition, identifying both current defects and areas requiring future attention.
The inspection was designed to allow maintenance to be planned proactively, prioritising remedial works based on condition and providing budget estimates to support future maintenance planning.
Cut Edge Corrosion
Moderate cut edge corrosion was identified across large sections of the profiled metal roof covering.
This commonly develops where the factory-applied protective coating has been compromised along the cut edge of the steel sheet, allowing corrosion to progressively work beneath the coating. Left untreated, this process can eventually affect sheet laps and fixings, leading to widespread deterioration and water ingress.
Fortunately, the corrosion remained within a repairable stage, allowing treatment using a specialist cut edge corrosion system. Addressing the issue now has the potential to significantly extend the lifespan of the existing roof while avoiding the substantial cost of premature sheet replacement.
Ageing Pipe Flashings
Several Dektite pipe flashings were approaching the end of their serviceable life.
These flexible weathering components naturally deteriorate through prolonged exposure to ultraviolet light and temperature fluctuations, eventually becoming brittle and susceptible to cracking. Replacement before failure represents a relatively low-cost maintenance item that can prevent significant water ingress around service penetrations.
Open Flues
A number of open flues were identified without suitable rain cowls or weather hoods.
Although often overlooked, these should be protected to reduce the risk of rainwater entering flue systems and creating unnecessary internal moisture issues.
Blocked Gutters
The client had reported isolated internal water ingress down sections of internal wall.
Our inspection identified several gutter sections that were heavily obstructed with debris, restricting rainwater flow and causing gutters to overflow during periods of heavy rainfall. Overflowing gutters remain one of the most common causes of preventable water ingress within commercial buildings.
A full gutter clean was recommended, together with the introduction of an annual inspection and maintenance programme..
Our Recommendations
Following the inspection, Verton Aerial Ltd provided a fully illustrated roof condition report detailing each identified defect, its priority, recommended remedial action and indicative budget costs.
This enables the client to prioritise maintenance based on condition, forecast expenditure and address defects before they develop into more disruptive and expensive repairs.
The Outcome
By identifying defects while they remain manageable, the client is now able to plan maintenance in a controlled and cost-effective manner rather than reacting to failures after they occur.
The inspection confirmed that, whilst the roof remains serviceable, relatively straightforward maintenance works carried out at the appropriate time have the potential to significantly extend its service life and reduce the risk of future disruption to manufacturing operations.
Planning commercial roof maintenance?
Understand the condition of your roof before minor defects become major expenditure.
Independent Roof Inspection Following Disputed Re-Roofing Works
Chapel Allerton, Leeds
Property Type: Victorian Mid-Terrace
Inspection Type: Independent Roof Condition Survey
Roof Covering: Natural Slate
Report Length: 18 Pages / 20 Annotated Images
Inspection Overview
✅ Slate roof covering
✅ Chimney stacks & flaunching
✅ Leadwork & abutments
✅ Valleys & drainage details
✅ Bonding gutter arrangements
✅ Roof ventilation provisions
✅ General workmanship assessment
The Challenge
The homeowner had commissioned a full natural slate re-roof approximately one year earlier.
Following completion, water ingress was reported around the chimney stacks. Conflicting opinions from roofing contractors left the client uncertain whether minor repairs or substantial remedial works were required.
Verton Aerial Ltd was instructed to provide an independent assessment of the roof's condition before further action was taken.
🚨 Defective Chimney Leadwork
The chimney abutment details were found to be one of the principal causes of water ingress into the property. Despite the client paying for new leadwork as part of the re-roofing project, no evidence of correctly installed lead soakers was identified. Instead, sections of lead substitute material had been used as cover flashings around the stacks, creating vulnerable junctions susceptible to water penetration.
The defects identified corresponded directly with the locations of reported internal leaks and fell significantly below the standard expected of a recently completed natural slate roof installation. Comprehensive replacement of the chimney leadwork would be required to achieve a durable and weatherproof detail.
🏠 Poor Slate Installation & Lack of Ventilation
The overall quality of the slate installation was found to be poor, with numerous examples of inconsistent setting out, excessive use of small slate cuts and areas of joint-on-joint slating observed across the roof slopes. Whilst some defects were aesthetic in nature, collectively they indicated a lack of care and attention during installation and resulted in a roof covering that fell below the standard expected standards.
In addition, no provision for roof space ventilation was identified during the inspection. Adequate ventilation is an important component of modern roof construction, helping to control moisture levels within the roof structure and reduce the risk of condensation-related issues. The absence of ventilation, combined with the wider workmanship concerns identified, further reinforced our conclusion that the installation had not been completed in accordance with recognised good roofing practice.
⚠️ Defective Valley Construction
Inspection of the roof valleys identified several workmanship concerns that would be expected to compromise their long-term performance. Valley slates had been poorly cut resulting in an inconsistent finish, while a number of slates had already begun to slip despite the roof being only approximately one year old.
The valleys also displayed signs of premature deterioration and were heavily reliant on workmanship that fell below the standard expected of a newly installed natural slate roof. Given the critical role valleys play in managing large volumes of rainwater, these defects were considered a high priority and likely to worsen if left unaddressed.
🧱 Poor Chimney Maintenance
The chimney stacks had been included within the scope of the recent roofing works, however the quality of maintenance carried out was found to be poor. New mortar had been applied directly over deteriorated existing flaunching rather than defective material being properly removed and renewed. Open mortar joints remained visible throughout the brickwork, leaving the stacks vulnerable to ongoing water penetration and accelerated weather-related deterioration.
Chimney pots were left open without suitable cowls installed.
This standard of workmanship is unlikely to provide a durable long-term repair and further remedial works would be required to restore the chimney stacks to a satisfactory condition.
🚨 Missing Bonding Gutter Between Adjoining Properties
At the junction between the subject property and the neighbouring roof slope, no evidence of a correctly formed bonding gutter was identified. Instead, the roofs appeared to be joined using a mortar fillet with a metal capping detail installed over the junction.
This is not considered an appropriate detail for a natural slate roof and is unlikely to provide a durable long-term weatherproof solution. Bonding gutters are typically required at these interfaces to safely manage rainwater and accommodate differential movement between adjoining properties. The absence of a properly constructed bonding gutter increases the risk of water penetration and future maintenance issues, particularly as the mortar detail deteriorates over time.
Overall Assessment
🔴 Overall Condition: Poor
Whilst the roof covering was only approximately one year old at the time of inspection, widespread workmanship defects were identified across multiple critical roof details. The most significant concerns related to the chimney leadwork, chimney maintenance and valley construction, all of which were considered consistent with the internal water ingress reported by the homeowner.
The quality of workmanship observed fell significantly below that expected of a recently completed natural slate roof installation and substantial remedial works were considered necessary to achieve a satisfactory long-term outcome.
Result
Rather than relying on conflicting contractor opinions, the homeowner received a comprehensive independent assessment supported by detailed aerial imagery.
The report enabled the client to successfully pursue a refund from the original contractor and obtain a clear understanding of the remedial works required.
Why Independent Roof Inspections Are Valuable
When significant roofing works have been completed, defects are not always obvious from ground level.
An independent roof inspection can:
✅ Verify workmanship quality
✅ Identify hidden defects
✅ Investigate leaks and water ingress
✅ Support warranty and dispute claims
✅ Help property owners make informed decisions
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