Here’s a steel and timber pergola we installed shortly before shut down in 2015 in Gateway Umhlanga Rocks Durban. It was for a new building called 1 on Lunar neat Gateway Hospital.
Due to the size of the pergola and the distance the beams needed to span between supports, we needed to include steel as the largest solid timber piece one can purchase is a 50 x 228 which needs to be supported every 3m odd to stop it sagging in the middle. Thicker wider pieces are available in laminated pine or saligna. To span over 6m one would need to laminate to 114 x 400 at a cost of more than a steel I Beam.
The steel was fabricated as per a drawing supplied by the client. Because we were directly on the coast, we hot dip galvanised the steel and then installed it. It isn’t sufficient to electroplate and powder coat when one is this close to the coast. Once installed it was painted to match the charcoal grey colour of the rest of the steel on the building. Galvanised steel needs to be acid washed in order to remove the residue left after the galvanising process, dried thoroughly, then primed with a galvanising primer and then two coats of Velvaglo enamel. It will require periodic maintenance by re-coating it.
The timber was cut to size and slotted in and attached to pre drilled and pre fixed tags on the main I beams. By pre drilling the holes for fixing eliminates drilling once galvanising has been done and thereby breaking the galvanising.
The timber was left to grey naturally rather than sealing it with an oil. This won’t shorten the life span of the balau as balau contains natural resins and oils which protect it from both rot and insect infestation. Oiling it merely makes it look different. Some people prefer the oiled looked some prefer the natural grey / silver look. Leaving it to grey naturally also eliminates any maintenance issues going forward. If anything one would just pressure wash it from time to time.
For a free no obligation quote contact us on 031 – 762 1795, or you can use the contact us form below. We can assist with all your outdoor wooden requirements as well as solid wooden floors.