Structurally sound shade structures often rely on well-designed and constructed footings to ensure the supporting columns and rigging are properly and permanently anchored to Mother Earth, and remain that way forever.
First, as always, comes proper design. The forces expected to act on each component of the structure are carefully calculated, an appropriate margin for safety is added, and a footing of sufficient dimensions and mass can then be designed to counter those forces. Most footings require steel reinforcing to ensure adequate strength and structural integrity.
Design for the steel reinforcing insert of a 2 cubic metre (~ 5 tonne) concrete footing.
Design for a footings insert onto which a steel column supporting a shade sail will be attached
Some footings require well-constructed timber or steel formwork to ensure their design size and shape is maintained during the installation process.
Footings excavation for a shade structure column with plywood formwork installed and the base prepared with a lean concrete base poured; this footing is ready for installation of the steel reinforcing insert “cage”.
A well-formed footings excavation in solid soil where no formwork is required; steel reinforcing cage is installed.
As well as the reinforcing cage, this footing is fitted with a sub-base plate, securely attached to the reinforcing cage, onto which a column can be secured with high strength bolts.
Steel inserts, which include sub-base plates, ready for installation in concrete footings for shade sail columns.
Once the inserts are in place concrete the excavations are filled with correctly specified concrete (generally a 25 MPa mix) and allowed to cure for approximately 1 week.
A completed steel-reinforced concrete footing; this one is designed to allow back-filling with soil and grass re-growth.
A Shades Asia “Monsoon” engineered umbrella firmly attached to its sub-ground footing.
Serious footings for some serious column.
Next time you admire a beautiful fabric shade structure, please spare a thought for the unsung heroes – the unseen footings doing their job of providing solid, permanent and more than adequate support for all the above-ground structure!
Shades Asia at work!