Already this year, during the supposedly milder summer, there has been the collapse of one canopy onto a forecourt in Leicestershire after torrential rain, and another canopy was blown off a Tesco site in Hull. Thankfully nobody was hurt in either incident, although two customers at the Leicestershire site had a lucky escape as they were in the shop when it happened and their cars were crushed.
Investigations are continuing so no conclusions about the cause of either incident can be made, but Global-MSI managing director, Martin Steggles, says that many canopies are being used that are well past their designed lifespan and are showing severe signs of corrosion.
Traditionally a filling station canopy will have been designed to have a working life of 25 years, but Global-MSI has records on canopies dating back to the 1960s and Steggles estimates there could be 250-500 canopies still in use that were built before 1970, another 500-1,000 built before 1980, and hundreds more that are pre-1989.
In addition to the age of a canopy, there are several other issues that can affect its condition. Coastal areas present a particularly hostile climate for canopies with salt and often the most extreme weather driving in off the sea and leading to corrosion although it is not just sites on the seafront, but even those several miles inland that can be affected by salt spray carried on the wind.
Prone to corrosion
In addition, there is one particular design feature that was commonly employed during the 1960s and 1970s that is particularly prone to corrosion. It involves the dual use of a steel member to act as both main structural beam and central rainwater gutter. A canopy using this detail was typically referred to as a 'spine beam' canopy and involved the welding together of two steel H-sections (one on top of the other) with the upper H-section receiving rainwater run-off from the canopy roof sheets. The use of spine beam canopies in the UK was generally phased out during the 1980s as the detail significantly accelerated corrosion of the main beam steelwork supporting the canopy deck.
Steggles said: "Global-MSI has carried out repair works on many spine beam canopies that currently remain in service in the UK. Most of the repair work undertaken dealt with rainwater leaks due to corroded welds around gutter outlets.
"Unfortunately rainwater leaks into the central core of a spine beam are concealed from view making it extremely difficult for a specialist to gauge the extent of the corrosion damage the spine beam has actually suffered. It is therefore strongly recommended that an owner of an existing spine beam canopy considers a full canopy replacement, as the true extent of damage to this type of canopy may only reveal itself through a corrosion-induced beam failure.
"The importance of undertaking regular maintenance and condition surveys on a known spine beam canopy cannot be overstressed, given the nature of the canopy's design will ultimately accelerate the structure's deterioration."
The foundations of canopies can also be vulnerable. The foundations of some older sites may be inadequate because they were built to standards that have since been stiffened as knowledge about foundations increased. In addition contaminated soil, a common problem on forecourt sites, or groundwater, can lead to corrosion.
Xmo Strata managing director, Steve Martin, agrees that a lot of older canopies are potentially dangerous and that owners should get them checked out. Not only is there the danger of a canopy collapsing, but any panels ripped off by wind can fly considerable distances and could have fatal consequences if they hit anyone.
Another seasonal problem for canopies, he says, is caused by leaf fall in autumn. These can block gutters and drains causing water to gather and this can then seep into electrics or cause additional corrosion. With the blockages often occurring in inaccessible locations such as inside pipes, clearing them is a specialist job, and Xmo Strata also acts proactively where such problems have occurred before.
He says the oil companies and larger operators tend to be more aware of the issues surrounding canopies and are more likely to have a programme of regular maintenance and repairs, but some smaller companies may not realise how important it is to take preventative measures.
Steggles agrees that regular maintenance is required and says it may pay off, as an owner who has ensured regular maintenance over a canopy's first 25 years, may find that it remains fit for purpose and, with regular inspections and maintenance, it could continue in use for at least another decade.
But he warns that owners of canopies over 25 years old must get them checked out by specialists because any problems may not be easily detected. New panels on an old structure may hide corrosion, and while it will look clean on the outside the panels may be fixed into a rotten structure with the danger that they will fall off or that the entire canopy could collapse, with catastrophic consequences.
Getting tanks ready for winter
Environmental services provider Adler and Allan is urging fuel tank owners to take steps now to make sure their tanks are winter ready, to prevent damage caused by the drop in temperature and limit the risk of pollution.
"Now is the perfect time for you to ensure fuel tanks are ready for the challenges that increased usage and colder weather brings of particular concern to fuel suppliers," said Alan Scrafton from Adler and Allan. "Faulty fuel tanks could spell operational downtime, a cost most businesses just can't afford to take.
"Apart from the practicalities, fuel tank owners are bound by legislative drivers which could result in hefty fines if not adhered to. The Fuel Storage Regulations cover all storage tanks, as well as interceptors, bunds and associated pipe work, with standards set and enforced by the Environment Agency.
"To avoid fines and keep these essential assets in proper working order, we recommend the following steps:
1. Make sure your tanks are inspected by an OFTEC registered engineer.
2. Protect pipes against corrosion and physical damage pipes below ground need visible inspection hatches and pipes above ground should be supported, using brackets, for example.
3. Check the Environment Agency's Pollution Prevention guidelines checklist, which includes advice about over-filling alarms and where to locate fuel tanks in relation to water courses.
4. Clean your tanks to ensure fuel quality. If water gets into a tank it can contaminate fuel and cause operational disruption.
5. In the event of a spill, make sure you have the correct spill kits on site. Expert help should be sought to help clean up pollution incidents.
"Keeping on top of maintenance will not only prevent pollution and downtime, it could also extend the life of your tanks, reducing the need for expensive replacements. All in all, making sure your fuel tanks are winter ready should be an essential task; one that affected businesses cannot afford to ignore."