The demand for maximising outdoor space is undoubtedly gaining pace across the public sector arena, especially with educational and healthcare establishments, where sheltered walkways, outdoor learning environments and protective entrance canopies are particularly popular options.
As with any extension, a canopy or walkway should be engineered specifically for the building it’s going to be attached to, or the ground it’s going to sit in to ensure that it:
- Meets the relevant performance and safety standards
- Is robust enough to stand the test of time
- Won’t require costly maintenance – to either the canopy itself or the adjacent wall or land
One of the most effective ways to ensure canopies and walkways are installed to the highest standard and provide optimum protection is to use site specific calculations. Typically conducted by a technical surveyor, these calculations encompass a number of technical on-site measurements, including wind speed, annual snowfall and nearby trees and roots, as well as the terrain in which the foundations will sit and the quality and structure of the wall that will support the canopy.
While it may seem somewhat strange to consider wind speed and snowfall for a canopy installation, they play a major part in how it should be built. So too, does the terrain, nearby trees, drainage systems and existing buildings, as they can all impact the build phase, performance and overall lifespan of the structure. For instance, the design of the canopy may have to factor in nearby trees and roots plus, how much they’re likely to grow and potentially impact the structure over the years.
The pull test
Site specific calculations are particularly key for cantilevered, wall hung canopies, as they determine if the identified wall is strong enough to take the weight of the required shelter.
Using a specific test known as the ‘pull test’, which is designed to mimic the weight of a canopy, a trained surveyor can ascertain whether additional foundation supports will be required in order to safeguard the canopy, the building and its users. Other factors that should be taken into account are the material, age and position of the wall, as well as type, weight and load bearing capacity of the selected canopy.
Understanding the importance of site specific calculations is the first step in ensuring canopies deliver on safety, performance and longevity, which are all key ingredients when investing in any building extension.
What’s more, conducting the right site specific calculations can make the difference between having a particular canopy or walkway and settling for an alternative design. With some minor adjustments to materials, fixtures, fittings and build techniques, almost any canopy installation is possible, providing the right technical factors have been taken into account from the outset.