How do you calculate how much weight a structure can withstand?
I am going to set up a hot tub that, when fully loaded, weighs 2500 kg.
Hot tub dimensions: 230x230 cm. It will be placed in the middle of the structure.
The structure also has braces 45x95 in each section (Not shown in the picture)
The joists rest on the inside against an existing framework
Decking 28x120
Joist dimension 45x145 (Double in the middle)
13 concrete plinths 50cm on packed sand
Posts 95x95
Will this hold, do you think? Over-dimensioned? Under-dimensioned?
I am going to set up a hot tub that, when fully loaded, weighs 2500 kg.
Hot tub dimensions: 230x230 cm. It will be placed in the middle of the structure.
The structure also has braces 45x95 in each section (Not shown in the picture)
The joists rest on the inside against an existing framework
Decking 28x120
Joist dimension 45x145 (Double in the middle)
13 concrete plinths 50cm on packed sand
Posts 95x95
Will this hold, do you think? Over-dimensioned? Under-dimensioned?
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There is a bit online that can be used to design timber structures. Träguiden, for example.
What you should make sure of is to have enough support posts. The posts and supports will probably hold up without issues, but the ground underneath might be the problem. Often, the support is placed on a concrete slab which then lies on the sand to increase the load-bearing capacity. How much force it can take up vertically depends a lot on the substrate and can be difficult to estimate. I would probably guess that 4 supports on concrete slabs and sand underneath should be able to hold 2500kg without major issues.
Will something else be built on top that might be damaged if it settles a few mm over time?
What you should make sure of is to have enough support posts. The posts and supports will probably hold up without issues, but the ground underneath might be the problem. Often, the support is placed on a concrete slab which then lies on the sand to increase the load-bearing capacity. How much force it can take up vertically depends a lot on the substrate and can be difficult to estimate. I would probably guess that 4 supports on concrete slabs and sand underneath should be able to hold 2500kg without major issues.
Will something else be built on top that might be damaged if it settles a few mm over time?
If the c/c distance between the beams is 600 mm, between the joists 1200 mm, and between the plinths 1200 mm, your intended dimensions are just sufficient. I suggest you step up a notch regarding the joists to 45x170.
Yes, double 45x145 will be good.