5 Ways Summer Heat Can Affect a Commercial Roof

As the summer sun finally finds its way to the UK, it’s important to note that your roof may face further challenges despite having weathered winter storms and spring hail.

For commercial roofs, the combination of extreme heat and high humidity during summer can exert significant strain on their structure and materials.

Unlike visible cracks or leaks caused by severe weather, heat-related damage can be subtle and challenging to detect.

Here are five key factors to watch out for as the summer heat bears down on your roof:

1. Thermal shock

Commercial roofs are often subjected to continuous sunlight exposure, reaching scorching temperatures on summer days.

As the sun sets, rapid temperature fluctuations occur, causing roof materials to expand during the day and contract at night.

This drastic temperature shift, known as thermal shock, can lead to warping or the formation of gaps in the roof over time.

2. Sun damage

Similar to the way that UV rays can harm your skin over time, they can also degrade roofing materials if they’re not protected.

Unprotected materials may bleach or blacken under the sun’s intense rays, with wood and shingles being particularly susceptible to damage.

3. Drying out

Intense roof heating can accelerate the drying process of oils present in certain roof materials. As roof linings or structural components dry, they become brittle and prone to cracking.

Left untreated, these fractures can compromise the roof’s structural integrity or degrade its waterproofing materials, potentially leading to leaks.

4. High humidity

The combination of elevated temperatures and humidity poses a significant risk to commercial roofs.

Expanded roofs due to high heat can absorb additional moisture, particularly in regions with humid climates, like the Southeast.

Moisture retention can result in water patches that may cause leaks, and if left unaddressed, could lead to roof collapses.

5. Popped seams and loose screws

The synergy of high temperatures, intense UV radiation, and the expansion and contraction of the roof surface can cause seams to pop and screws to become loose.

Vulnerable areas such as penetrations for skylights and vents are prone to this type of damage.

How you can help your commercial roof

Once you understand the potential damage that heat can cause to your commercial roof, the next step is taking action.

While you could wait and hope for the best, this passive approach could lead to costly repairs in the future. Instead, adopting a proactive strategy is a much wiser choice.

Regular Inspections

Schedule roof surveys twice a year – once in the spring to prepare for the summer heat, and again in the autumn to get ready for the colder months.

Establishing a regular inspection program with a trusted commercial roofing contractor is invaluable.

These routine checks can identify and address issues early, ensuring your roof remains in good condition year-round.

Cool Roof Technology

Utilise cool roof technology to enhance your building’s energy efficiency.

Options like special coatings, single-ply membranes, and EPDM rubber roofing are designed with reflective properties that can deflect up to 85% of solar heat.

This keeps your roof’s temperature closer to that of the ambient air, significantly reducing heat absorption. This can lower your cooling costs by up to 30% or more, depending on your location.


Ensure that your attic or cellar is properly ventilated. Improved airflow in these areas helps prevent roofing materials from absorbing and retaining heat.

Good ventilation not only reduces heat buildup but also provides minor insulation benefits, contributing to a more comfortable building interior.

Inspect your summer roof with NWIR

To safeguard your roof from long-term issues, it’s crucial to conduct regular self-inspections during the summer and enlist the expertise of a professional roofing company for routine roof surveys.

Our commercial roofing contractors are always on hand to help with their experience in surveys and inspections.

If you want to talk directly to a trusted team member, get in touch and call us on 0800 046 1500.