Here Comes the Sun! How Does it Affect your Roof?

Most of the time when we think about weather damage to a flat roof, we tend to think about the damage done in winter by storms, rain, snow, ice and other harsh weather conditions.  However, in the warmer summer months, the sun takes its toll and can cause damage to the roof too.  Today we’re going to take a look at how the summer sunshine affects your flat roof.

Whilst a flat roof is designed to stand up to a range of different weather conditions, the vagaries of our British weather can speed up the wear and tear process and here are the main culprits:

• Direct Heat – exposure to direct heat over a period of time means that the roofing materials used on your flat roof may warm up to a temperature sufficient to evaporate the oils in the roofing material, causing cracks, warping or peeling.  This is because high temperatures will cause the materials to expand whilst low temperatures cause them to contract. 
• Thermal Shock - The daily rising and setting of the sun in the warmer months means that the flat roof will be subject to the changing temperatures experienced when we have hot, sunny days, followed by cooler nights.  This can lead to thermal shock caused by the continuous expansion and contraction of the roofing membrane materials.
• UV Radiation – sunlight comprises different types of radiation, one of which is ultraviolet (UV) radiation. UV rays affect the materials used to construct a flat roof on a molecular level.  This means that oxygen molecules will combine with the materials used on your flat roof.  For instance, if your roofing membrane has asphalt, oxygen will combine with the hydrocarbons in the asphalt, resulting in them becoming dry and brittle.  Eventually, the UV rays will break down the molecular structure of the roofing materials which leads to wear and tear as the chemical bonds break down.  It’s vital to be aware that strong UV rays can penetrate clouds and cause damage even on the cloudy days.

Luckily, here in the UK, we tend not to experience really high temperatures (though last summer’s heatwave was a bit of an exception!).  However, there are some measures you can take to ensure that your flat room doesn’t suffer too much from weather conditions. 

Carrying out regular roof inspections will enable you to prevent any lasting damage from occurring and nip problems in the bud before they get too severe.  Keeping on top of all rooftop maintenance, such as removing debris, cleaning or replacing parts, etc., will help your roof to last longer.  Be sure to check carefully in areas where rooftop machinery and plant is located as this is where damage is more likely to occur.  Likewise, if you have any rooftop safety equ8pment, such as demarcation barriers providing access to maintenance areas, these areas are where people walk on the roof, so a stringent inspection is vital.