Hello,
The trusses are likely freestanding between the outer walls because:
1. I have never seen a truss with such a small span that is NOT self-supporting, and I have seen many.
2. If a truss (usually with a large span) is NOT freestanding, the load-bearing wall should be placed under the truss where the braces meet the lower chord. That is where the load is transferred down. It seems (without measuring) that this is not the case on your drawing.
3. The type of nail plate specified is, I believe, one that is pressed into the timber during manufacturing, so the number of nails is not specified.
4. A wall with 45*45mm studs can naturally bear some load, but I have never seen a house with such a small dimension in load-bearing walls.
For further guidance, you could open up an interior wall near the ceiling. If the interior wall has a wall plate of stronger dimension and mounted "upright" like a beam, I might feel a hint of doubt. However, if the wall plate is also dim 45*45mm and the wall studs are not placed directly under the truss, I would put a good beer in the fridge and start the reciprocating saw.
The trusses are likely freestanding between the outer walls because:
1. I have never seen a truss with such a small span that is NOT self-supporting, and I have seen many.
2. If a truss (usually with a large span) is NOT freestanding, the load-bearing wall should be placed under the truss where the braces meet the lower chord. That is where the load is transferred down. It seems (without measuring) that this is not the case on your drawing.
3. The type of nail plate specified is, I believe, one that is pressed into the timber during manufacturing, so the number of nails is not specified.
4. A wall with 45*45mm studs can naturally bear some load, but I have never seen a house with such a small dimension in load-bearing walls.
For further guidance, you could open up an interior wall near the ceiling. If the interior wall has a wall plate of stronger dimension and mounted "upright" like a beam, I might feel a hint of doubt. However, if the wall plate is also dim 45*45mm and the wall studs are not placed directly under the truss, I would put a good beer in the fridge and start the reciprocating saw.
Even though I am an old designer, I can't give you a clear answer. (without bringing out the calculation programs again)
The truss undeniably looks weak to be self-supporting. But on the other hand, I don't know any designer who would advocate for a load-bearing wall made of 45x45 lumber either. Hardly non-load-bearing either. Even though it certainly holds for quite large loads. But then the lintel should be made of significantly stronger lumber.
My final guess is that the trusses are self-supporting, as the snow load is only 1.0. But you should do further research before doing anything.
The truss undeniably looks weak to be self-supporting. But on the other hand, I don't know any designer who would advocate for a load-bearing wall made of 45x45 lumber either. Hardly non-load-bearing either. Even though it certainly holds for quite large loads. But then the lintel should be made of significantly stronger lumber.
My final guess is that the trusses are self-supporting, as the snow load is only 1.0. But you should do further research before doing anything.
Yes, jc1972's comment no. 2 is something I have also noted, and combined with the information in the table I linked to earlier, I find it very difficult to see how this roof truss would not be self-supporting. On the contrary, it is even slightly over-dimensioned in the lower frame 
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· Etelä Pohjanmaa
· 2 467 posts
No one is so dumb as to build a load-bearing wall with 45x45. It's even flimsier than regular non-load-bearing interior walls normally are. You could almost break such a dimension against your knee. That's not a heart wall, and I wouldn't hesitate for a second to take it down.
One more thing - I have also looked a bit in different tables and from what I can see, the underbeam you mentioned is over-dimensioned. However, I am also unsure about the connection on the underbeam (nail plate).
All the walls in the house are 45*45 studs with single plasterboard without insulation. In other words, one big resonance box. I'm pretty sure that when the house was built, the ground floor was made as one large room and then interior walls were put up, which should also suggest that they are free-standing.
All the walls in the house are 45*45 studs with single plasterboard without insulation. In other words, one big resonance box. I'm pretty sure that when the house was built, the ground floor was made as one large room and then interior walls were put up, which should also suggest that they are free-standing.
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If it is a prefab house, this is correct, and it is likely not loose trusses but rather the trusses and joists are delivered connected, they are 1200 mm wide. Quickly assembled.keckepro said:
Often, the furring strips under these joists were also mounted upon delivery, which meant that there were end-to-end joints straight across. This resulted in the ceilings, in my case tongue-and-groove boards, cracking at the joints. I don't know when this happened, as the house had stood for 30 years when we moved in, but it wasn't pretty.
I tore everything down and re-furred with 28/70 s300, then plastered everything. Looks good!
And free-spanning then? Or not?fahlis said:
I was thinking of kicking off the roof book and trying a similar truss calculation.
But now I don't know if I have it installed on any computer, so it came to a halt.
Hello
I have asked some people in the industry and everyone agrees that they are self-supporting. However, the project is on hold, instead, there will be an extension on the opposite side of the kitchen. More about this in another future thread.
I have asked some people in the industry and everyone agrees that they are self-supporting. However, the project is on hold, instead, there will be an extension on the opposite side of the kitchen. More about this in another future thread.