Common Flat Roof Problems
The flat roofing market here in the UK is in a particularly healthy state right now, they provide a low cost option for many projects as they are cheaper and easier to install, inspect and maintain. This is why so many of our commercial and industrial buildings in Britain boast flat roofs, despite the fact they are seen as problematic and suffer from a host of problems arising from standing water. Pooling water is the single most common cause of flat roof issues which can turn into serious problems if not dealt with in a timely manner. The most common flat roof problems can be divided into three different categories:
Dissimilar Materials – most flat roofs are fabricated from a variety of materials including glass, plastics, masonry and metals. Industrial and commercial roofs will often feature a multitude of heating units, pipes, and other plant that make the roof geometry challenging to cover effectively. Whatever combination of materials is used, ensuring long-term adhesion and sealing between dissimilar materials is crucial. Flashings can be particularly problematic and they’re a common component in both flat and pitched roofs, where metal, brick and felt or bitumen often all meet. When exposed to varying temperatures and weather conditions these materials react differently, changing shape and size, depending on each material’s characteristics. The different expansion and contraction rates can result in roof weakness which allows water ingress.
Joints and Seams – these are exceptionally troublesome on many roofs, mostly due to the effects of movement. All buildings will undergo a degree of movement due to thermal expansion, contraction and wind but joints and seams are the most vulnerable areas. Gaps and lips may appear which can be worsened by the wind uplift, leading to water ingress or further exposure of unprotected materials to weathering and corrosion. Continuous exposure to the elements may result in the delamination of the roof covering, which creates vulnerable areas, increasing the likelihood of falls through the roof surface when inspection, maintenance and repair tasks are carried out. As the roofing material degrades, extra care must be taken by using collective protection equipment such as rooftop walkways and demarcation barriers. Parapet walls may become vulnerable at the joints as a result of movement between the brickwork or movement in the building. This problem is also seen in the seams around skylights and glazing bars which degrade over time due to the dissimilar materials used and movement.
Other types of damage may be long term or short term in nature. Long term damage usually arises if the roof is not regularly maintained – it will suffer from aging and neglect and, over time, flexible roof coverings are exposed to environmental factors such as UV exposure, rain and wind. This leads to brittleness and cracking which makes working on the roof far more dangerous. Wildlife may also have a detrimental effect on the roof – bird litter may corrode the plastic coatings on some roofing systems. High levels will cause damage and deterioration of the roof lining which will also lead to leaks.