Monthly Archives: May 2016

Getting it right… from the ground up!

Foundation PotWhen considering the installation of a canopy how much thought do you give to the groundwork and the foundations on which your structure will be built? It probably isn’t high on your list of priorities when choosing your canopy and the company who will install it.

At Twinfix we like to get it right from the ground up, so that is why we have detailed below some crucial factors that need to be considered when having a canopy installed.

What are foundations?

Foundations are normally a cubic mass of concrete used to not only support the canopy and prevent it from sinking into the ground, but also to weigh it down and prevent it from blowing away in strong winds. Every canopy needs foundations and it is very important that these are completed correctly and safely in accordance with the relevant British Standards.

What size foundations are needed?

Foundation sizes can be very large and can vary in size dramatically depending on the canopy material being used, canopy shape and ground conditions. They can even vary depending on the canopy location within the UK, taking into account snow and wind loads for that area based on British Standards. It is important the cubic mass of concrete is calculated correctly and individually for each project.

How should they be constructed?

Concrete needs to be a certain grade, normally at a minimum C30 mix. When the canopy frame is mechanically or chemically fixed to the foundations the concrete must then be cured for around one week, depending on the weather conditions. The concrete can’t therefore be poured at the same time as erecting the canopy frame. If a canopy is being installed at the same time as the foundations then it must be correctly ‘root’ fixed to prevent it from later working loose as the concrete cures.

What else?

Sometimes if there are services (gas, water, electric, etc.) in the area then an MR or thermal imaging scan of the ground will be needed. Specialist equipment is required for this to ensure that the groundwork does not interfere with any services. Not all underground services can be found from a scan and at times these are only discovered during excavation. It is important that the design team is notified at this point before work continues and that the relevant design amendments are made and recorded. These amendments could be to bridge over services and/or resize or reposition the foundation pots.

It is also important that the ground condition is assessed once the holes have been dug and prior to pouring concrete. If the ground is not suitable or stable enough to resist the weight of the foundation then it could sink over time causing the attached canopy post to twist and ultimately collapse.

In conclusion

The hardest part of a canopy design is sometimes below the ground. Not enough concrete and the canopy could blow away in the wind, too much concrete or the wrong shape could cause damage to services or sinking and twisting canopies. Our advice would be to check with your chosen installer that they too are getting it right… from the ground up!