Commercial Roof Recoating

A range of commercial properties, industrial units and agricultural buildings may either have steel profile cladded roofs or more traditional commercial roofs made out of corrugated metal sheets. Steel has been used in the construction industry for a long time and is favoured for its strength, flexibility and because it can be recycled. This versatile metal is usually coated to protect the surface from corrosion before it is used as a roofing material. Once roofs are in situ, onsite commercial roof recoating is common practice for many reasons.

During the manufacturing of modern industrial roofs, a high tensile steel sheet is covered in zinc followed by layers of coating that are cured in extremely hot ovens within a factory. PVC Plastisol is a widespread product used to coat steel sheeting for roofs (also for cladded elevations) and this durable finish can last from 15 to 25 years. Cladding for roofs can also be painted with a polyester enamel coating which can last for up to 20 years.

These coated roofing sheets are strong as well as being resistant to corrosion for years, but like many coatings on metal, they fail over time. Pollution, extremes of temperature, rain, hail and snow as well as ultra violet light all take their toll on roof coatings. Bright, highly saturated colours often fade more quickly than more subtle tones and red pigments are more susceptible to UV light. Some pre-finished cladding can last up to 25 years, but if a commercial property is located near the coast, the coating will deteriorate faster as it also does if the weather has been extreme for a few seasons running.

As steel roofs age, the original coating sometimes peels back around fasteners and where the sheets have been cut. This can lead to cut edge corrosion which can be repaired if caught early enough. All these factors not only slowly decay the roof coating and eventually the metal substrate itself, they also de-value commercial properties. Even if a coating remains intact, a company may wish to change their corporate colours or a rebranding rollout may be taking place and sometimes a lease repairing covenant stipulates a recoat.

If a roof is not maintained properly it can cause long term difficulties affecting the integrity of the whole building. Consequently, it is a good idea to remove moss and algae otherwise they can cause problems if left to grow for too long. Moss can hold over 20% more water than a plain roof surface which adds a great stress to roofs especially when it freezes during cold spells. It can also block gutters and downpipes.

A roof should be cleaned and maintained regularly to prevent deterioration of the substrate, but appearance is important too. Erosion and colour fading effect how roof coatings look and wind borne dust will make a roof seem dirty, so refurbishment is also about aesthetics. Powdering does look unsightly, but once the original coating has chalked and broken down, the exposed metal substrate is also vulnerable to corrosion as a result of damp seeping in. If the steel isn’t recoated it will continue to be subjected to weathering and will then fail to protect the rest of the structure of the building.

A new coat of paint on previously coated roof sheets can increase the lifespan of roofs by a further 10 years and even longer if they are maintained properly and over-painted while the finish is still intact. The whole of a large roof or a small patch of deteriorated roofing or cladding can be repainted to protect the substrate. Furthermore, it is not just roofs themselves that can be cleaned and recoated, skylights, guttering, fascias and wall cladding can all be refurbished. Over-coating is an efficient way of adding a new protective layer on to metal roofs and associated features and can almost always be carried out without disrupting the operations within the building. Because it prevents structural deterioration and improves aesthetics, commercial roof recoating is a wise long term investment.