But is it not already built? How does it feel when you walk on it?
If it doesn't flex much, then it's completely fine. A wooden structure doesn't suddenly break without warning. You will get deflection and deformations that warn you if it is under-dimensioned.
If it doesn't flex much, then it's completely fine. A wooden structure doesn't suddenly break without warning. You will get deflection and deformations that warn you if it is under-dimensioned.
Thicker decking can do a lot for the feel but it doesn't actually affect the flexibility of the structure itself. It is only how much it flexes between the floor joists that decking thickness makes a significant difference.
I have 4 meters between the wall and the outer bearing beam. (The space underneath is used as a carport) I am using beams of 45x220 with 50 cc and 28x145 decking timber. I find it completely solid, even when we've had a party and there were surely 20 people on the deck.
I am skeptical of the idea that the calculation of useful load for a balcony would depend on the construction method. Rather, I think it reflects the greater height above ground that a balcony typically represents. I have gone through a number of older building codes to see if a pattern can be found. In both SBN 75 and Boverket's New Construction Regulations from 1988, the same rules apply for balconies as for roof terraces, which I think supports my interpretation. BABS 46, which was the first national Swedish building code, mentions 400 kg/m2 for balconies and 300 kg/m2 for patios.
I think that height above ground is reasonably a factor that determines the choice of safety class and not useful load. The larger useful load for balconies, I guess, is because it is such a small area. The problem with surface load is that the total load can become too small on small areas.
Compare the opposite with large areas where under certain circumstances you are allowed to make load reduction.
Compare the opposite with large areas where under certain circumstances you are allowed to make load reduction.
I also believe that the balcony's limited space may have influenced the choice of useful load. It's also interesting to see how norm constructors over the years try different divisions of loads to find more accurate calculation methods, only to eventually return to the simple area-based one. A competent constructor can always make deviations if they can verify them. Some rules in building legislation are particularly persistent, usually those lacking a scientific basis. A good example is the rule of 4.5 m to the property boundary. It first appears in the Building Ordinance for the country's cities from 1874 and still exists in PBL (or if it's PBF).
I didn't say you were wrong in dimension, just corrected the dimensioned loads for the balcony.larsbj said:
I find it a bit strange that a carpenter can't use a simple app to capture recommended dimensions for timber. It took me 5 minutes to check these.
So, the widespread load probably mainly comes from the snow load when there's half a meter of wet snow in March... ? I think the balcony will survive. Just don't lay the decking too tightly so that the meltwater can flow through. Keep in mind that wet decking expands. So even if you have large gaps in the summer, it can become completely tight on wet winter days.