When is a roof survey required before specifying a coating system?
In many cases, industrial roof coatings are specified without a detailed understanding of the roof’s existing condition. While this may be sufficient for straightforward refurbishments, there are situations where a more thorough survey is essential to ensure that the proposed system is appropriate.
The purpose of a roof survey is not simply to identify obvious defects, but to understand how the roof has performed over time — including previous repairs, hidden deterioration and areas of weakness that may influence specification decisions.
This guidance outlines when a survey is typically required, the risks of proceeding without one, and the different levels of inspection that may be appropriate depending on the project.
When a Survey is Typically Required
A roof survey is not always necessary for coating works, particularly where the roof condition is well understood and recent inspection data is available. However, surveys are typically recommended in the following situations:
- Unknown roof history
Where there is limited information on previous coatings, repairs or maintenance. - Evidence of corrosion or coating failure
Particularly where cut edge corrosion, end lap corrosion or widespread coating breakdown is visible. - Multiple previous repairs
Localised patch repairs can conceal wider deterioration, especially at laps and fixings. - Water ingress or reported leaks
Internal issues may not directly correspond with visible external defects. - Pre-acquisition or dilapidations assessments
Where the objective is to understand liability, risk and remaining service life.
In these situations, relying solely on visual observations or desktop assessments can lead to incorrect assumptions about the condition of the roof.
Risks of proceeding without a roof survey
Where a coating system is specified without a clear understanding of the roof condition, there is an increased risk of:
- Incorrect system selection
For example, applying a coating to a roof where underlying deterioration requires more extensive intervention. - Unidentified defects
Issues such as underside corrosion, failed laps or loose fixings may not be visible without closer inspection. - Inaccurate specification documents
Which can lead to ambiguity during tender and increase the likelihood of contractor-led substitutions. - Unexpected costs during the works
Additional repairs identified after commencement can lead to variations and delays.
In practice, the cost of a survey is often minimal when compared to the potential cost implications of an inappropriate or incomplete specification.
Independent vs manufacturer-led roof surveys
Roof surveys can be carried out either independently or by manufacturers offering coating systems. Both approaches can be appropriate, depending on the objectives of the project.
An independent roof survey is typically commissioned where a completely impartial assessment is required. This is often the case for pre-acquisition surveys, dilapidations, or where multiple refurbishment options are being considered, including repair, overcladding or full replacement.
A manufacturer-led survey is generally more focused on assessing whether a coating system is suitable and, if so, identifying the level of preparation and repair work required to support that specification. In these situations, the survey is used to inform a practical and cost-effective refurbishment approach rather than to explore all possible options.
In practice, the distinction is less about right or wrong, and more about the scope of the assessment. Where the objective is to determine the most appropriate overall strategy for the roof, an independent survey may be preferred. Where the intention is to refurbish using a coating system, a manufacturer-led survey can provide a more targeted and efficient route to specification.
Survey support for coating specifications
Where a coating-based refurbishment is being considered, survey input can help to:
- Confirm that the existing roof is suitable for coating
- Identify areas requiring localised repair prior to application
- Assess the extent of corrosion at cut edges, laps and fixings
- Inform specification documents and reduce ambiguity at tender stage
Liquasil can provide survey support in this context, either as part of a proposed coating specification or as a standalone assessment where required. The level of involvement can be tailored depending on whether the requirement is for initial guidance, specification support or a more detailed condition assessment.
Direct Access
We strongly recommend the use of a cherry picker to conduct roof surveys. They allow the surveyor to directly access or get close to the roof surface so that any defects can be identified, examined and documented. Roofs can only be accessed where it is safe to do so.
Drone Survey
Drone surveys can be conducted when weather and flight conditions allow. Flights cannot take place in restricted areas such as close proximity to airports and flight paths. It should also be noted that although drone photography can be very good, it is also quite limited for identifying certain defects.
Desktop Study
If you have conducted your own roof survey or have detailed photographs of your roof, a desktop study might be appropriate. Our specialist roofing surveyors can use your images to provide an indication as to whether or not your roof is suitable for coating.
Hidden Roof Defects
Hiring a cherry picker to get access to an industrial roof might seem like an added expense, but it often pays dividends, since it allows the surveyor to see exactly what is happening at roof level and make the correct assumptions with regard to coating and other repairs.
In the image opposite, you can see where a previously treated area of cut edge corrosion has been scraped away to reveal extensive corrosion beneath, leading to perforation of the roof sheets.
If this defect was not known prior to works commencing, any roof coating specification would have been incorrect.
This would have resulted in substantial, additional costs that had not been budgeted for.
The cost of a cherry picker is around £550. The extra cost of treating a defect like this can run into several thousand pounds.
Where a closer inspection is required, our industrial metal roof inspection checklist for building surveyors provides a practical framework.
If you are unsure whether a survey is required, this is typically something that can be established quickly based on basic project information.
Call us today on 0121 709 5352 for assistance with your roof surveying requirements.