Load-bearing capacity 220mm K24

[Mikael_L]

I wasn't aware of the program Dimensionering on byggbeskrivningar.se before. It was a great tip! It's just a shame that you can't calculate with unspecified lumber, but understandably so since there isn't a definitive value for such lumber that can be guaranteed.

C14 (K12) you could probably use as relatively equivalent to fine and straight lumberyard wood without wane, cracks, many knots, or other defects.
Wood that is worse, i.e., has some of these defects, probably shouldn't be used at all in load-bearing parts.

 

[johanssonjohan]

Hi,

I’m borrowing the thread a bit for a similar question.

I’m going to build a new apartment on the attic floor. Floor joists 75*230 cc60. The longest span is about 5m. How much, approximately, can I load this with before I encounter problems with deflections? I'm especially considering the risk of cracking in the ceiling of the apartment below and the risk of cracks in the bathroom/waterproofing in the bathroom in the attic.

Very grateful for an estimate.

Best regards,
Johan

 

[Mikael_L]

5-meter span sounds too long to me.

I somewhat doubt that it meets the building regulations' requirements with normal load (= light regular apartment load).
I would make sure to have it inspected (the condition it's in) and then calculated if it needs reinforcement. I would not dare to lay tile on this joist.

 

[Nimajneb]

If you use glulam, cc30, and glued floor chipboard, it can work. But I would definitely let an expert give their opinion.

 

[johanssonjohan]

Hi,

Thanks for the quick responses. The floor structure is already in place, so these are the conditions. Designed for attic storage. House from 1939. The question is whether one can relatively easily reinforce the floor structure? Today there is chipboard between the beams and planks on top.

Best regards,
Johan