A canopy is one of the most useful things you can add to a commercial site. It keeps goods dry while trucks load, shelters equipment and outdoor storage, and turns a wet yard into usable working space. Because it’s open, it behaves differently from an enclosed building, and that shapes the design.
Common uses #
- loading and unloading bays
- covered outdoor storage for materials and pallets
- roofs over generators, plant and equipment
- wash bays and workshop yards
- covered walkways between buildings
We’ve designed and installed a roof over an existing 250 kVA generator, and a fully enclosed loading building on a busy commercial site.
Clearance for trucks #
The standard maximum height for heavy vehicles on New Zealand roads is 4.3 m. Allow for that plus a margin, and remember that tipping trucks, raised loaders and forklifts with masts extended may need more. The lowest point of the frame, not the ridge, is what matters.
Wind uplift #
An open canopy catches wind from underneath, which tries to lift the roof off. Canopies often need bigger footings and hold-downs than you’d expect for a light roof. That’s an engineering job, not something to guess.
Freestanding or attached? #
Attaching a canopy to an existing building can save columns, but it adds load to the existing frame and changes how it handles wind. The existing building needs to be checked by an engineer first. A freestanding canopy avoids that question, at the cost of extra columns.
Water #
A canopy roof collects a lot of rain. Plan gutters, downpipes and where the water goes, and make sure it doesn’t simply dump onto the loading area or back against the existing building.
Durability: plan the maintenance #
Air flows freely under a canopy, and in much of New Zealand that air carries salt. The salt settles on the underside of the structure, which rain never washes. Unwashed salt is a durability issue, so canopies need regular maintenance: washing down with a hose, brooming, or pressure washing. Depending on how close you are to the sea, that might be once a year or several times a year. For a lot of New Zealand, this is what it takes to get the durability you expect.
There are many ways to deal with this, including the type of steel used, a pre-painted steel soffit liner on the underside, or a paint coating on the structure for extra durability. Talk to us early so we can look at the durability side of your canopy with you.
Fire and consent #
Canopies are building work and usually need building consent. Near a boundary, they can come into the fire design. On sites with existing buildings, they may also affect the fire separation between buildings. Many canopies are built out towards the boundary, so talk to us early. We’ll work through any fire implications, whether that means fire rating or confirming it isn’t needed.
Lighting and safety #
Good lighting under a canopy makes night loading safer. Column protection, such as bollards, stops forklift damage.
Talk to Steelspan #
Tell us what needs covering and what moves underneath it, and we’ll design a canopy that works with your site. Use our Easy Shed Quote or call 0800 787 726.
