I want to make a small scaffold about 2.5 metres high with a base about is 2.5 x 1.2 meters- for my self I am about 75kg - Please can you advise What size galvanized tubing do I need ? would 20 x 20 x 1.6mm Galvanised Steel Square Tube Grade 200 be strong enough ?

  • 4
    Buy a rated product. Why choose galv tube? welding that is nasty.
    – Solar Mike
    Sep 14, 2022 at 9:28
  • 2
    Or rent a rated product. Scaffolding is widely available for rent.
    – Ecnerwal
    Sep 14, 2022 at 11:59
  • 1
    There is, in the US, "masons scaffolding" that is approx. those dimensions you are looking for. It is modular, stackable and come in different heights has wheels available, safety rails etc. If you must build it yourself, how high will it need to go and how good are you at welding? Are you a certified welder, for example? If it is braced well enough, it be made out of really lightweight material, but it all comes back to how tall?
    – Jack
    Sep 14, 2022 at 13:15
  • @TigerGuy yes they do - the aluminium self assembly units are very effective. All the fixed joints are welded.
    – Solar Mike
    Sep 14, 2022 at 14:34
  • 2
    @TigerGuy the parts which are assembled are virtually always welded (in a factory, with, one expects, x-ray inspection) - it appears our questioner wants to bypass that factory. A Darwin Award Winning approach, most likely.
    – Ecnerwal
    Sep 14, 2022 at 14:37

1 Answer 1


For our readers on the North American side of the pond, the 20mm x 1.6mm square tube is approximately equivalent to our 3/4 inch 16 gauge square tube. Unfortunately, that tube is much too small for this job. Your life (or somebody's, anyway) is in the balance -- at a standing height of 2.5m, it's not overly dramatic to say that.

For reference, the end frame of the scaffold I'm familiar with stands 2m high and is perhaps 1.5m wide. A second end frame would stand parallel to the first about 2.5m away with two X-shape cross braces fixed between them. That's comparable in size to what you've described. The end frame would be constructed of round tube, perhaps 32mm diameter and 2.0mm wall thickness while the cross braces are round and about 22mm x 1.5mm. (note: sizes estimated from memory; I didn't go out and measure!)

Such a scaffold can readily support two workers, a plank or two of 15-20kg, and some tools or materials as well. It's far stronger than is necessary to support a single 75kg person. But ladders and scaffolds should not be "value engineered" to minimize tubing size -- it's far too easy that down the road its usage will change or grow, it'll be called upon to support more weight than was originally contemplated, and failure could result.

  • "Value engineering" (I like that term!) is a good way to undersize it for its intended purpose, not just potential future uses.
    – FreeMan
    Sep 14, 2022 at 14:24

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