Hoarding wind loads not taken lightly in England’s windiest county

Managing hoarding wind loads is a key challenge for any site that requires securing.  With more than 10 years’ experience in construction site hoarding in Cornwall, Perimeter’s has proven again and again it is up to that challenge.

According to Met Office data, Cornwall lifts the crown as England’s windiest county.  In fact with average wind speeds being between 10 and 20 knots, 80% of the county has higher average wind speeds than England’s windiest city, Liverpool (average wind speed 11.8 knots).


Hoarding wind loads to expect in West Cornwall

Calm isn’t a  word that springs to mind considering the climate of Cornwall’s  north and west coasts. From Culdrose, round Land’s End, through to Bude, the Atlantic’s full force bears down on  Britain’s western tip. The 118 mph gusts reached at Gwennap in 1979 remain a record. But as the chart above shows, peak gusts of  approaching 100 mph are to be expected (85knots = 97mph) on the Peninsula.  Fine for surfers, often tough for fisherman, but potentially disastrous for those charged with securing construction sites.

The hoarding wind loads force is with you, squared!!

Average wind loads, even high average wind loads, are not THE challenge for hoarding. It’s peak wind loads.  What does this mean for construction sites, which endure for a year or possibly longer.  It means engineering a hoarding solution that will be strong enough whenever that peak wind hits.


Hoarding wind loads are proportional to the square of the wind speed

It’s worth keeping in mind the force loading hoarding from the wind follows a squares law, i.e. if the peak wind speed is double the average, the wind load on the hoarding at the peak would be four times higher.  But even in the UK’s calmer areas, the difference in forces at play on a typical summer’s day and a stormy winter one can be startling.

Hoarding wind loads to expect at Heathrow


Heathrow’s average winds never breach the 10 knots below which much of Cornwall never falls. But don’t let that fool you.  You should expect December’s gusts at Heathrow to approach 90 mph, only a little less than Cornwall’s.

Let’s put that another way. The peak wind load you should expect your hoarding to cope with over the course of a year will be about 64 times higher than the average wind load it might experience over a typical day. Even in the calm South East of England.

Good enough for summer, won’t be good enough

Perimeters re-usable hoarding system can weather these storms, year round.  Whatever time of year Perimeters hoarding is installed it doesn’t weather or deteriorate.  Strong u-PVC panels stay firmly fixed to a steel scaffold. For support we utilise either our non-ground breaking kentledge system or C24 timber posts with concrete foundations.  Whatever Perimeters hoarding solution you choose, there will be a site specific engineering study undertaken by an independent structural engineer. Your site’s probable wind loads, soil conditions, elevation and surroundings are all factored into our designs.

By contrast, a timber hoarding solution may be nice and tidy when its installed one fine spring day. But come the following winter, or the winter after that?  The timber will weather, delaminate and buckle.  However, it may not be the cosmetic damage that you should worry about most. The boards that were once well fixed to their posts may have distorted, moved, and may have loosened their attachment.  In high winds, this could spell disaster.

Perimeters hoarding is good all year round, countrywide

But there is no need to worry when choosing a partner for your site hoarding.  Perimeters’ hoarding protects sites across England’s windiest county, as it has done for over a decade.  Why not give us a call.