Flat roof maintenance: what, when and why?

Flat roofs are a popular choice for many commercial, and industrial buildings due to a combination of low installation costs, modern aesthetics, and practical features like the ability to install solar panels or HVAC equipment. However, maintenance of flat roofs is often overlooked, which can result in costly repairs, water damage and structural issues. This article explores the importance of flat roof maintenance, how to design for durability, and tips for a proper maintenance routine.

Why flat roof maintenance is important

·       Preventing water damage and leaks

The laws of gravity mean that flat roofs don’t drain as effectively as sloped roofs, making them more prone to water pooling if not designed and maintained properly. Over time, standing water can lead to leaks, mould growth, and deterioration of roofing materials. Regular maintenance can identify and address these issues early.

·       Extending the lifespan of your flat roof

Proper upkeep can significantly extend the lifespan of your flat roof. Regular inspections and minor repairs prevent small issues from escalating into major problems that could necessitate a full replacement.

·       Meeting building regulations

BS 6229:2018 – the British Standard for flat roofs with continuously supported flexible waterproof coverings – contains a section on inspection and maintenance, which says:

“A flat roof should be inspected at least twice yearly; in autumn to ensure it is clear of leaves, dirt and debris, outlets are not blocked, and the roof is free draining; in spring to discover and rectify any damage due to weather. Green, blue and other specialist roofs should be inspected in accordance with the designer’s original inspection plan.”

It also recommends that additional inspections should be carried out in the event of extreme weather conditions, vandalism, and construction work on or adjacent to the roof, including the installation of equipment (e.g. HVAC plant, telecoms equipment or solar panels). Also, if surrounded by trees, more frequent inspections may be necessary.

·       Keeping your flat roof warranty valid

If the flat roof coverings were specified by a manufacturer, there will usually be a warranty in place. To meet the terms of the warranty, manufacturers normally stipulate that regular inspection and maintenance must take place. Many warranties require that records be maintained and available for viewing by the manufacturer, in the case of a claim.

·       Ensuring energy efficiency

Damaged or poorly maintained flat roofs can compromise insulation, increasing energy costs. A well-maintained roof helps regulate indoor temperatures and reduces energy consumption.

Flat roof maintenance. What does good look like?

Maintaining a flat roof doesn’t have to be complicated. Here are some actionable tips for establishing an effective maintenance routine:

·       Regular roof inspections

Schedule roof inspections at least twice a year—preferably in spring and autumn —and after extreme weather events like storms or heavy snow.

During inspections, check for:

• debris accumulation on the roof surface and outlets.
• cracks or blisters in the roofing material.
• loose or missing flashing.
• pooling water or clogged drainage systems.

●        Clear debris from the roof surface

Leaves, dirt, and other debris can accumulate on flat roofs, blocking drainage systems and making it more likely that water will pool on the surface. Regularly remove debris to ensure proper drainage and prevent damage to the roofing materials.

●        Clear drainage systems

Flat roofs rely heavily on drainage systems to remove water. Clean gutters, downpipes, and rainwater outlets, to ensure that they remain clear of blockages. These systems need to be checked regularly to ensure they function correctly, as blocked or clogged drains can lead to water pooling on the roof, increasing the risk of leaks and structural damage.

●       Check for damage

Inspect the roof for visible signs of damage or wear. This includes checking for cracks, blisters, punctures, or tears in the waterproofing membrane. Any damage should be promptly repaired to prevent water ingress, which could lead to more significant issues.

●        Check for leaks

Inspect the interior of your building for signs of water damage, such as stains on the ceiling or walls. Leaks may not always be visible on the roof surface, so it pays to keep an eye out for any indications of damp internally.

●        Assess roof penetration

British Standards recommend inspecting any penetrations in the roof, such as vents, skylights, and pipes. These areas are often vulnerable to damage and require special attention to ensure that the flashing around the penetrations remains intact and watertight.

●        Repair issues promptly

Small cracks, blisters, or punctures in the roofing material can deteriorate quickly if left untreated. Contact a professional roofer to address these issues as soon as they arise.

Design your flat roof for low maintenance

All roofs need regular upkeep, but a well-designed roof will make the maintenance process much more straightforward.

• Ensure the pitch is right: a roof with an insufficient pitch can lead to water pooling, which puts strain on the roof system.
• The right height of upstands: the height of upstands should be at least 150mm, otherwise, heavy rainfall may cause water to overflow and seep into the roof structure.
• Weak detailing around roof penetrations: areas around rooflights, vent pipes, and other penetrations are vulnerable to leaks if not properly detailed. These should be designed with extra attention to prevent weak spots.

Ensure that your roof is designed by a qualified roofing expert who carries Professional Indemnity Insurance to protect the design work.

Flat roof maintenance mistakes to avoid

• Don’t ignore small problems: Minor issues can escalate quickly if not addressed. Always prioritise timely repairs.
• Don’t overload the roof: Flat roofs are not commonly designed to bear excessive weight. Avoid storing heavy equipment or materials on the roof unless it has been specifically designed to do so.
• Avoid abrasive chemicals: When cleaning the roof, avoid chemicals that could damage the roofing material. Stick to manufacturer recommended solutions.
• Do NOT be tempted to skip inspections: Routine inspections are the backbone of flat roof maintenance. Skipping them increases the likelihood of costly damage.

Flat roof maintenance is crucial for protecting your investment and ensuring the safety and efficiency of your property. By establishing a regular maintenance regime and addressing issues promptly you can extend the lifespan of your roof and avoid expensive repairs.

Whether you handle routine tasks yourself or hire professionals, the key is consistency. A well-maintained flat roof can protect your building for years to come.

 For advice on selecting the right materials for your next flat roof project, how to tackle issues created by a lack of maintenance or ponding, call our expert team on 0161 777 7554 or email sales@lancastria.com. We look forward to speaking with you.