Another from the ministry of silly questions…I’d like to support a lightweight tarpaulin over my back yard. Single slope, high side attached to the house and low side attached to a scaffolding pole, running horizontally between two walls. Fair weather, no high winds or pooling. The run of pole would be 8 meters. The longest poles seem to be 6m, so I need to use a coupling. Will this be strong enough – ish? I imagine the most stressed point would be just around the edges of the coupling, so If I used two joints/couplings in the bar, wouldn’t I half the strain on a single one?Also if I made the joints at 1m and 7m would that be better than to have a joint in the middle where the most flexing will be?Also bit more expensive, but with Aluminium the bar will be 20kg lighter – buy will it be as strong joint wise?Will a tubular coupling be as good as a external one?If anyone knows.. Thanks!
The problem with your proposal is that you realise that the wind/rain could have an effect but chose to ignore the consequences if it occurs. 'Proper' scaffolding is designed and such an unsupported span would never occur in a 'normal' scaffold so the standard calculations would not work. There is also the possible effect on the walls, could they take an abnormal load? I would look at theatrical or music stage hire using trussed beams.
