Covering All Bases: the Importance of Flat Roof Surveys

flat roof survey

Replacing a roof can be a costly and time-consuming job, but a flat roof survey can often mean the difference between extending a roof’s lifespan, or its failure and replacement. Sunny Lotay, national commercial manager at PermaRoof UK, gives an overview of the processes involved with and the benefits of incorporating periodic surveys into a flat roof’s life cycle.

flat roof surveys - Sunny Lotay
Sunny Lotay, National Commercial Manager, PermaRoof UK

FLAT ROOF SURVEYS are done to determine the condition of an existing roof and to pinpoint any problems or areas of concern, such as waterproofing and structural issues, flashing problems, ponding water and more. If left unidentified, or not resolved quickly and effectively, these issues can have a long-term impact on the lifespan and structural integrity of the roof, leading to costly repairs or even premature failure.

While these surveys are generally performed visually, there may be certain cases that require some intrusion – such as core sampling – into the existing structure to help identify issues lying beneath the surface.

This assessment then informs and determines the correct flat roof system proposal to put forward. Proposals could include several measures or fixes, such as thermal upgrades, structural and drainage improvements, maintenance access walkways or fall arrest systems – to name just a few.

Annual Flat Roof Surveys

While people tend to wait until a problem occurs or, in some cases just before a major project is about to start, to have a flat roof survey undertaken – it’s best to opt for a more proactive and consistent approach.

A general annual check can help to minimise the possibility of issues developing and identify the areas that may only require some quick repairs or maintenance. As a rule of thumb, flat roofs should have a twice-yearly check to clear any debris or outlet blockages, ensuring the longevity of the roof and that it remains watertight.

flat roof survey In addition, as roofs age and issues start to occur, it is advisable that a roof survey is conducted as quickly as possible to determine when a replacement will need to be made. This will afford enough time to identify the correct system build and ensure compliance requirements are met.

While there’s not technically a ‘best’ time of year to have a roof survey done, as it generally depends on a variety of factors not least the condition of the roof, I would usually recommend precautionary surveys be taken in late spring or summer. This allows time for any potential repairs to be made before the wet winter months take hold.

Survey Elements

Surveys can include a number of parts, from checking thermal regulation and fall of water discharge to structural soundness and whether there are enough outlets. Depending on the results of the survey, there might not be any action required. Therefore, when finding a specification manager to carry out the survey, it’s important that you opt for someone who is able to offer a no obligation, completely free of charge survey, core test and condition report.

There are a number of factors that need to be considered when preparing to conduct a roof survey. They include checking the weather and ensuring all of the correct equipment is to hand. Also, importantly the health and safety measures needed on site.

flat roof surveyDepending on the roof size and complexity, a flat roof survey can take anywhere from a morning to, in some cases, a couple of days.

Once the survey is complete, a roof report is written making the recommendations required.

In Practice

At a recent survey, a core test was undertaken at a residential block of flats in south London to identify the build-up of the roof. This test determined that it was a cold roof, with timber substrate and asphalt on top as the waterproofing element.

Through this report a recommendation was made to upgrade from a cold roof to a warm roof, using the existing asphalt roof as a vapour control layer.

Consisting of a brand-new 120mm insulation layer, along with an 18mm OSB board and topped by the Firestone Rubbergard EPDM system, a watertight roof with a 20-year warranty was delivered.

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