I have cast a slab at 9.2x14.4 meters... it seems to be a bit of a problem to get self-supporting truss beams in that width (length), I have talked with the "local" truss manufacturer and they said it wasn't possible, the next one said there were no problems, but you might need to shorten the CC distance between the trusses.Funkis -38 said:
I then got in contact with Arvidsson's trusses who said it was possible, and I also received a drawing so now I'm more confident that it can be done..
The storage space will be 4x2.25 meters, roof pitch 38 degrees.
The height of the trusses is 4 meters, which means the total height will be nearly 8.5 meters... damn it that I'm so afraid of heights
however, it is only storage in the attic of course and not residential load
hmm the ceiling gypsum in my current garage has cracked... they've installed the gypsum in the same direction as the rafters and it has cracked at every screw joint on the edge of the gypsum board, nothing visible on the long sides...big mike said:If the ceiling gypsum cracks, there's too much load
should I be worried?
Useful load for residential floors is (usually) set to 2.0 kN/m[SUP]2[/SUP], i.e., about 200kg per square meter. What is the allowable useful load on these storage attics then, which cannot handle residential load?
50kg/m[SUP]2[/SUP], 100 kg/m[SUP]2[/SUP] ...?
edit:
It could also be the design for "temporary inconvenience" that prevents the use as a residence, not a permanently distributed load. But still, these are connected, if it sags from point load, it will sag from static load too. And the ceiling bends, etc.
edit2:
I went back in the thread and checked the pictures, it seems that the floor is also at cc1200 mm, I think the use of the attic for useful load seems quite optimistic. Some leftover panel boards and empty boxes, and it should handle that, but I’m not sure if it can load a few semi-heavy items.
Can't you check the roof truss drawing for what distributed useful load they've designed for? It usually says something on the lower frame of the truss.
50kg/m[SUP]2[/SUP], 100 kg/m[SUP]2[/SUP] ...?
edit:
It could also be the design for "temporary inconvenience" that prevents the use as a residence, not a permanently distributed load. But still, these are connected, if it sags from point load, it will sag from static load too. And the ceiling bends, etc.
edit2:
I went back in the thread and checked the pictures, it seems that the floor is also at cc1200 mm, I think the use of the attic for useful load seems quite optimistic. Some leftover panel boards and empty boxes, and it should handle that, but I’m not sure if it can load a few semi-heavy items.
Can't you check the roof truss drawing for what distributed useful load they've designed for? It usually says something on the lower frame of the truss.
Last edited:
the following is on my quote
Loads: EN 1991 + SS-NA
loads (N/M2)
snow load 3000
wind load 852
live load 1 500
2 1000
3 500
Loads: EN 1991 + SS-NA
loads (N/M2)
snow load 3000
wind load 852
live load 1 500
2 1000
3 500
150 kg/sqm.thestrut said:
Are these trusses you requested to be dimensioned for storage space (storage load)?
Snow zone 3 I can also deduce, seems to match well with the northern parts of Gävleborg county.
But what 2 and 3 are, I don't know.
Last edited:
I couldn't get the "table" quite like in the quote, it looks more like this... if you remove the underline.
1____500
2____1000
3____500
but you probably have a handle on it anyway...
yes, I have requested to get as large a storage space as possible in the attic... getting it to the point where it can handle residential load I assume will be difficult, but I can double-check with them
but storage load should be enough, right? even if you have a teenager at some point who wants their own little nook without a toilet/kitchen...
1____500
2____1000
3____500
but you probably have a handle on it anyway...
yes, I have requested to get as large a storage space as possible in the attic... getting it to the point where it can handle residential load I assume will be difficult, but I can double-check with them
but storage load should be enough, right? even if you have a teenager at some point who wants their own little nook without a toilet/kitchen...
OK.
Well then, I don't know what 1, 2, and 3 mean.
Maybe different load cases or safety factors.
Or maybe it's different parts of the roof truss, like the loft, between the loft, the loft.
Perhaps someone else knows.
Well then, I don't know what 1, 2, and 3 mean.
Maybe different load cases or safety factors.
Or maybe it's different parts of the roof truss, like the loft, between the loft, the loft.
Perhaps someone else knows.
received as a response that the number 2 ____ 1000
means 1000 NM per m2, 10 NM = 1 kg so it is 100 kg per m2
means 1000 NM per m2, 10 NM = 1 kg so it is 100 kg per m2
OK.
But then it would be interesting to know what:
1____500
and
3____500
mean.
500 is easy to guess as 500N/m2, i.e., about 50kg/m2.
But why different values for the load indication—the secret must lie in the numbers 1, 2, and 3.
But then it would be interesting to know what:
1____500
and
3____500
mean.
500 is easy to guess as 500N/m2, i.e., about 50kg/m2.
But why different values for the load indication—the secret must lie in the numbers 1, 2, and 3.
agree, will see if I get answers on them!
Did you receive any roof truss drawings in connection with this information?
I thought it might be marked on this drawing with numbers 1-3 on which areas of the truss the load capacity applies..?
edit, and a nitpicky thing ...
So 10N = 1.02 kg (approximately), but I almost always do exactly like you and round it to 1 kg.
(And maybe you already knew all this ...)
* 1 kg is usually said to correspond to 9.81 N, but as far as I know, that's some kind of average value, but I believe the differences between, for example, the poles and the equator only show up at about the 3rd decimal. I can't be bothered to look this up.
I thought it might be marked on this drawing with numbers 1-3 on which areas of the truss the load capacity applies..?
edit, and a nitpicky thing ...
1N = about 0.102 kg (but it depends on gravity, varies partly by latitude and also local deviations depending on the bedrock and altitude).thestrut said:
So 10N = 1.02 kg (approximately), but I almost always do exactly like you and round it to 1 kg.
(And maybe you already knew all this ...
)* 1 kg is usually said to correspond to 9.81 N, but as far as I know, that's some kind of average value, but I believe the differences between, for example, the poles and the equator only show up at about the 3rd decimal. I can't be bothered to look this up.
Last edited:
the response from the truss manufacturer is:
Different useful loads, bound free, etc. NL 2 is e.g. personal load.
NL 2 determines, in other words, if it is a storeroom or a residence.
I had no clue about that N.... probably doesn't matter to me as a layperson either since it's so close, but thanks for a detailed description!
the more you know, the less you know
Different useful loads, bound free, etc. NL 2 is e.g. personal load.
NL 2 determines, in other words, if it is a storeroom or a residence.
I had no clue about that N.... probably doesn't matter to me as a layperson either since it's so close, but thanks for a detailed description!
the more you know, the less you know