Distribute weight using a platform/decking

My balcony is solid concrete and supports 400kg/m2 of weight and I would like to put an inflatable jacuzzi on the balcony. The inflatable jacuzzi I am looking at holds 790 liters of water within the internal dimensions of 1.4x1.4m. I worked out the kg/m2 as: 790 / (1.4 x 1.4), which 403kg/m2. Thus already at the limit without any people. The actual weight of the inflatable jacuzzi is negligible and not provided, so I am not including this in my calculations. I would like to know if building a 2m x 2m platform/decking using 5 or 6 beams of 2x4 running in one direction (33cm or 40cm apart) with decking running perpendicular on top would help to distribute the weight so it is below the 400kg/m2 limit? If so, what would be the best way to proceed and can this be proven with any calculations? If you're able to help then please provide a quote for providing this information. Thank you, Joe