What sort of steel is used for pergolas?
As with steel roofing materials, steel used in the construction of the pergola frame itself needs to be protected from rust and corrosion. This can be done with a 100% zinc coating (known as galvanised steel) or it can be coated in a zinc-aluminium combination commercially known as Zincalume or Galvalume. The steel can be powder coated with a paint and then baked, both for added visual appeal and to provide a much wider range of colours to choose from.
What are the advantages of steel pergolas?
Areas which see a lot of damp weather or rising ground water will quickly deteriorate a wooden pole that has been sunk into the ground. Steel poles won’t deteriorate with time or water exposure like timber does, and it can also provide a lot more strength. Using steel also greatly reduces the risk of your home catching alight should it be exposed to a bushfire. It can be a council regulation in bushfire prone areas to use only non-flammable products in your outdoor areas, and where that's the case, steel certainly fits the bill.
Steel is also more weatherproof than wood, provided that the galvanised coating remains intact. It also takes paint very easily and is very difficult to damage – only large impacts can make a dent. Steel is more expensive than most woods but it requires less replacement and less maintenance in the long term. It may not have the look and feel of wood, but this can actually be a selling point to some who may prefer solid colour to natural wood grain.
How are steel pergolas installed?
Steel framed pergolas are constructed in much the same way as wood framed ones. The poles are aligned straight and concreted in, then the beams are bolted to the poles and affixed to the house. From there, battens are then bolted or screwed to the beams. There may be differences in the types of bolts and screws you’ll require due to the differing thicknesses of the steel, but many steel pergolas are sold as a kit so will already have everything you need.