Should I worry about my flat roof in the hot sun

Is your roof in a good state of repair? Have you considered what may happen to your flat roof in the hot sun?

Freezing temperatures, heavy downpours, ice, snow – surely winter is the time you should be concerned about your flat roof, right?

Actually no. If your roof is not in the best condition, you may need to know what could happen to your flat roof in the hot sun.

The fact is that the summer months can be just as damaging as the colder season if your flat roof is vulnerable to the elements. As temperatures rise, the stress placed on a roof increases, which is extremely problematic if it is already weak. Left unchecked, this added stress could result in the roof failing when the heavy rain returns.

Are you already worried about the state of your flat roof? If so, now is the time to arrange for a professional to inspect it – don’t wait until after the summer. Waiting until autumn will not only exacerbate any problems but it will also be more difficult to find an installer as it’s a busier time for the industry. Simply put, a damaged flat roof in the hot sun can spell disaster.

When it comes to monitoring your flat roof in the hot sun, there are five key issues you should look out for:

  • Blistering
  • Thermal movement
  • Standing water
  • Flashing damage
  • Poor installation

Your flat roof in the hot sun – blistering

High Tech Membrane roofing flat roofers for Essex

Traditional felt flat roofs are prone to blistering. Water can penetrate tiny cracks or holes in the felt membrane. As temperatures rise, this water heats up, expanding and lifting the felt. As a result, you could end up with blisters or bubbles, which will need to be repaired.

If repaired early, only the affected areas will need to be replaced. However, if you have ignored the problem and the blistering is extensive, the only solution will be to replace the entire roof.

Your flat roof in the hot sun – thermal movement

Summer usually means warm days and cool nights, which can spell disaster for your roof. Fluctuations in temperature can cause your traditional felt roof to expand and contract, allowing water to penetrate the membrane.

Your flat roof in the hot sun – standing water

High Tech Membrane Roofing Flat Roofers Essex

Hot and dry one minute; throwing it down the next – the British weather is nothing if not unreliable! It is rare not to see flash flooding at some point during the summer, which leads to standing water.

Standing water is water that doesn’t evaporate or drain within 72 hours.

Flat roofs actually do have a very slight pitch but some of them are too flat (yes this is actually a thing!). Some may also have insufficient drainage. If so, standing water can result in leakages.

Your flat roof in the hot sun – flashing damage

Built up moisture can result in fungal growth; the summer’s increased hours of daylight can accelerate this growth. Flashing damage can compromise your flat roof’s drainage, which is an essential element of retaining its condition.

Your flat roof in the hot sun – poor installation

Are you confident that your flat roof was installed by an expert? Are you sure that it was professionally installed and built to last?

Sadly, not every roof is fitted properly. If installation was poor or carried out using substandard materials, these issues will be magnified by the warmer weather. Over time your flat roof can sag, allowing rainwater to pool and increase weight and pressure.

What’s the solution?

High Tech Membrane Roofing flat roofers Essex

Are you concerned about your flat roof in the hot sun? Now is the time to get it inspected before the really hot weather arrives. Always make sure you choose a recommended installer who will provide you with honest, expert advice.

If the best course of action is to replace your roof, it is imperative that you take full advantage of the cutting edge materials available, as well as any warranties and guarantees on the chosen products and installers’ workmanship.

Here at High-Tech Membrane Roofing, we have carefully selected single-ply membrane roofing systems that have been specifically engineered to provide a wide range of benefits, including:

  • 100% watertight
  • Breathable membrane, designed to eradicate condensation, algae and moss
  • Unaffected by damaging UV rays
  • Unaffected by expansion and contraction
  • Virtually maintenance free
  • Commercial-grade
  • Lifetime guarantee

Please contact High-Tech Membrane Roofing on today for more information about our flat roofing membranes.

By Published On: May 26, 2022Categories: Flat Roof
  • By Steve Thornton

    If you have a question about this or any of our blogs, or about any of our services, then please do not hesitate to get in touch.

    We will always try and answer your question quickly and professionally.

In 1999, High-Tech Membrane Roofing introduced homeowners in Essex, Kent and London regions to the most advanced flat roofing systems offering the ultimate in flat roof protection.

Get a quote

Our friendly team will listen, explain your options and provide a clear plan. No matter the size of your project, it all starts with a free, no-obligation quote.

Why do so many modern buildings have flat roofs?

February 10, 2026|

Most older properties are built with traditional pitched roofs, which begs the question: Why do so many modern buildings have flat roofs? You want to build your dream home. You’re planning an extension. Considering [...]

What is the best skylight for a flat roof?

January 2, 2026|

Flat roofs have become increasingly popular for modern homes and extensions, offering a clean and minimalistic look. However, they can sometimes leave interior spaces feeling darker than pitched roof properties. Installing a flat roof [...]

How Long Do Flat Roof Extensions Last?

April 30, 2025|

Flat roof extensions are ideal if you're looking to create a stylish, functional spaces without the expense and complexity of a pitched roof. Whether you're adding a new kitchen, a garden room or a [...]

What is the best flat roof for a garage?

March 24, 2025|

According to GoCompare, one in 10 people have had their garage converted within the last five years, emphasising just how crucial garages can be to homeowners, not just useful storage spaces but adaptable to your [...]