Currently calculating various options for floor joists for our planned extension. The span will be 5.0-5.20m (we have some leeway there) laminated floor chipboard The maximum dimension for the joists can be 220 (225 also works).
So far, there are 3 options
45X220 c24 cc300 max span 5.21 m 70x220 c24 cc600 max span 5.01m (cheapest total price) 56x220 Glulam cc600 max span 5.11m (super expensive)
Ideally, I would prefer standard 45 in cc600 to make it easier later when installing insulation, etc. Plus, it takes less time.
I've tried to find tables for the maximum span for structural wood c30, but haven't been able to find any.
Does anyone have tables or know the maximum span for 45x220 c30 flooring?
So far, there are 3 options
45X220 c24 cc300 max span 5.21 m 70x220 c24 cc600 max span 5.01m (cheapest total price) 56x220 Glulam cc600 max span 5.11m (super expensive)
Ideally, I would prefer standard 45 in cc600 to make it easier later when installing insulation, etc. Plus, it takes less time.
I've tried to find tables for the maximum span for structural wood c30, but haven't been able to find any.
Does anyone have tables or know the maximum span for 45x220 c30 flooring?
Member
· Etelä Pohjanmaa
· 2 467 posts
The strength classifications are just EU nonsense to protect the internal market. If you order c30, you'll probably get c24 with a different stamp on it. I would go with cc325 in your case to make it a bit stronger. Then it's enough to split the insulation board into two equal parts.
What limits is probably not the fracture toughness but that the floor joist flexes if it's too thin. It won't make any difference with C24 or C30 in that regard.
cc325 can cause issues with the laying of the floor chipboard. In that case, it must be floor chipboard that does not need to be joined on a joist.
cc325 can cause issues with the laying of the floor chipboard. In that case, it must be floor chipboard that does not need to be joined on a joist.
What is the length across the span? In the other direction, that is.
Ok, I don't have much knowledge on this subject.
I just read that c24 allows for a longer span than c14 and thought that c30 should allow for an even greater span.
Cc325? Do you mean cc300, or?
The span in the other direction is about 6500 so it's out of the question.
I'm probably leaning towards using cc600 with 70x220.
I just read that c24 allows for a longer span than c14 and thought that c30 should allow for an even greater span.
Cc325? Do you mean cc300, or?
The span in the other direction is about 6500 so it's out of the question.
I'm probably leaning towards using cc600 with 70x220.
If you are going to take insulation boards for cc600 and split them in half, it must be cc320-cc325 for the insulation to fit. With cc300 you will have to cut off a strip.
I would probably have gone with 70x220 with cc600. Cutting the insulation boards can at most be a few minutes of extra work. Alternatively, you can take slightly thinner insulation so that you can probably squish down the insulation without cutting it.
I would probably have gone with 70x220 with cc600. Cutting the insulation boards can at most be a few minutes of extra work. Alternatively, you can take slightly thinner insulation so that you can probably squish down the insulation without cutting it.
Member
· Etelä Pohjanmaa
· 2 467 posts
If you want to use cc600, I would use 45x220 and cross-brace in the middle instead of 70x220. I would guess that 45x220 with cross-braces becomes as strong as 70x220 without. And cheaper.
You need to account for a higher E-modulus on C30 timber than on C24, so it does indeed matter for deflection.F f91jsw said: