Bespoke Steel and Glass Canopy and Covered Walkway - Sheffield School
A one off canopy for a school in Sheffield, originally built for main contractor Kier. It covers the main entrance doors, then turns the corner and runs on as a covered walkway along the elevation.
Nothing about it came out of a catalogue. The frame is galvanised steel, the roof is tinted glass, and the posts are steel plate clad in timber so that the structure reads as something warmer than bare steelwork in a school playground.
Project overview
- Client: A school in Sheffield, through main contractor Kier
- Scope: Entrance canopy and covered walkway, designed, made and installed
- Frame: Galvanised steel beams, rafters and raking struts
- Roof: Tinted glass
- Posts: Steel plate connections clad both sides in timber, on galvanised steel base plates bolted to the existing surface
- Fixing: Wall beam fixed back into the existing school brickwork, with free standing posts on the open side
- Made: In Dio-Met's own workshop in Sheffield
Why it was made rather than bought
Catalogue canopies come in modules. Fixed widths, fixed projections, fixed post centres. They are the right answer when the building will accept one, and a lot of buildings will.
This one would not. The canopy had to clear a set of double doors, follow an elevation that changes, turn a corner, land on existing tarmac rather than new foundations, and fix back into brickwork that was already there and already a certain age. Every one of those is a dimension somebody has to decide, and none of them are on a standard drawing.
So bespoke was not the upgrade here. It was the only version that fitted.
Posts that look like timber and work like steel
The detail worth describing is the posts, because they are not what they appear to be.
Each one is a steel plate connection with timber cladding fixed either side of it, sandwiching the steelwork in the middle. From a few feet away you read a timber post. Structurally it is a steel column with a plated head taking the beam and a galvanised base plate at the foot, bolted down to the surface.
There are two reasons to build a post that way. The first is that the connections want to be steel. A canopy post is carrying a glass roof, taking wind uplift and resisting whatever a school playground does to it, and those loads go through bolted plate, not through timber. The second is that a run of bare galvanised columns outside a primary school entrance looks like scaffolding. The cladding softens it and hides the plates and the bolt heads at the same time.
It costs more than either a plain steel post or a plain timber one. It is the sort of thing that only happens when the frame is being drawn for that building rather than picked off a page.
Tinted glass rather than clear
The roof is tinted glass. Over an entrance that faces the open playground, a clear roof puts full daylight and glare straight down onto the doors and into the rooms behind them. Tinting takes the edge off that without turning the space underneath into a tunnel, which is what a solid roof does.
Glass also ages differently to the plastic alternatives. Polycarbonate and similar sheet materials are cheaper and lighter, and over a long enough period outdoors they yellow, craze and go brittle. Glass does not. The trade is weight, and weight is the reason the frame under it is steel rather than aluminium.
Fixing back to a building that was already there
On the building side the canopy hangs off a beam fixed into the existing brickwork. On the open side it stands on its own posts.
That split is normal and it is also where retrofit canopies go wrong. The wall has to be able to take it, and that is a question to settle before anything is made rather than on the morning of the install. On a job inside a main contractor's programme it also has to suit a sequence somebody else is running, so the steel turns up finished and goes together, instead of being adjusted on site.
What bespoke fabrication actually means here
Bespoke gets used loosely, so it is worth saying what it involves on a job like this.
It is surveyed, drawn and approved before anything is cut. It is then made in our own workshop in Sheffield rather than bought in and badged. On almost every bespoke framework we build we bolt the whole thing together in the workshop first, check it, photograph it and then take it apart again before it goes for galvanising. Customers are welcome to come and see that stage, and the trial building photographs are sent to anyone who asks.
That step exists because of the order things happen in. Galvanised steel cannot be cut or welded afterwards without ruining the coating, so a mistake found on site is a trip back to the galvanisers rather than a quick fix with a grinder. It is far cheaper to find it on the workshop floor.
Structural steelwork we fabricate today is covered by our UKCA BS EN 1090-2 factory production control certification, independently audited by Alcumus ISOQAR, with coded welders and documented quality control behind it.
Frequently asked questions
Do you make canopies for schools and commercial buildings?
Yes. Entrance canopies, covered walkways, link canopies between buildings and outdoor teaching shelters, made to suit the building rather than to a standard module. There is more on our commercial canopies and covered walkways page. We work directly for end clients and as a subcontractor to main contractors.
Glass or polycarbonate?
Glass if you want it to look the same in twenty years. Polycarbonate is cheaper and lighter and it does work, but it discolours and becomes brittle outdoors over a long period. Glass is heavier, which means the frame carrying it has to be designed for the load rather than scaled down to save steel.
Can a canopy fix to an existing building?
Usually, and that is how most of them are done. What matters is what the wall is made of and what condition it is in, which we establish at survey rather than assume. Where the wall cannot take it, the canopy stands on its own posts on both sides instead.
Why clad steel posts in timber?
Appearance, mainly. Steel is what you want at the connections, and timber is what suits the setting in places like schools and nurseries. Cladding the plate on both sides gets both, and covers the bolt heads at the same time.
What finish do you use outdoors?
Hot dip galvanising is the baseline, and it can be powder coated over the galvanising where a colour is wanted. Paint straight onto bare steel is the reason so much outdoor steelwork rusts within a few years. There is more on our material and finish standards page.
Do you work for main contractors?
Yes, and this project came through one. Subcontract packages on a contractor run programme are routine for us, and the commercial terms are agreed job by job.
Explore more from Dio-Met
Related
- Commercial canopies and covered walkways
- Bespoke and made to measure metalwork
- Glass door canopies
- How we trial build before anything is finished
Similar projects
- Frosted glass door canopies, Hallam Mews, Sheffield
- Steel ramp and access handrails, Shiregreen
- Steel railings, access gate and staircase, Barnsley
- View all our bespoke projects
Helpful guides
Got a building that needs covering?
Send the elevation, rough dimensions and a photograph of what the canopy has to fix to, to sales@diomet.co.uk, and we will tell you what is possible and roughly what it costs. Call 0114 243 9009 if it is easier to talk through, or see more of this work on our commercial canopies page.