I think you are absolutely right about the sizing of the joists. Nemas problemas.
But I'm more curious about how you've planned the attachment to the exterior walls.
If you don't have a solid tension anchorage for the floor joists, the force on the upper connection of the lower arms will become critical. But I suspect you have that included in your calculations.
But I'm more curious about how you've planned the attachment to the exterior walls.
If you don't have a solid tension anchorage for the floor joists, the force on the upper connection of the lower arms will become critical. But I suspect you have that included in your calculations.
I had not counted the space between the beams as part of the construction; the roof truss you have chosen should only provide vertical forces and not require anything from the beams.
One way is to place a support beam on the inside of the studs and attach the beams with joist hangers. You can then also achieve a better vapor barrier if this is installed first.
One way is to place a support beam on the inside of the studs and attach the beams with joist hangers. You can then also achieve a better vapor barrier if this is installed first.
This would indeed be the best, yes, but it is unfortunately very difficult if you, like me, want a difference of only 5 degrees between the internal and external roof angle and also build in snow zone 3.pbengtsson said:
Exactly, that's exactly how I'll do it, but with a solution without joist hangers, the idea is for the vapor plastic to pass uninterrupted past the intermediate floor.pbengtsson said:
Exactly, that's where the truss will want to break under heavy load, so the mid-floor structure should also function as a collar tie holding the truss together.titanium said:
The mid-floor structure will therefore not only rest on the outer walls but be properly anchored.
Isn't 4.6 that much? What is your roof pitch? Is the house only 4 meters deep?Gabbe1 said:
I have 4.2 and with 27 degrees roof pitch, and I have a total of 5.5 in ceiling height in the open part.....
Hope the wall studs are dimensioned for the great bending load they are exposed to if the intermediate floor is to help hold the rafters together. It's quite a lever arm between the rafter and the intermediate floor!Gabbe1 said:
I encounter this model in prefabricated houses, with a span of 3.8 m. They shouldn't be too expensive/remarkable to manufacture yourself.. http://www.byggbasen.com/prod/hi-balkar/1756.html?office=16225
I was hoping for 30 degrees externally and 25 degrees internally, completely open to the ridge according to my sketch. The house is 8m wide, with the span of the intermediate floor being 4m x 2 (there is a load-bearing wall/beam in the middle of the ground floor). The ceiling height on the upper floor will vary between 1m and 3m. I very much want to avoid going below 1m at the minimum, and therefore the intermediate floor should be kept as thin as possible.Enk Projektet said:
The lever arm between the rafter and the intermediate floor is 1m. And yes, here I need to take the help of a structural engineer to calculate how much bending load the wall studs can handle, and as a result of that calculation, the degree of freestanding of the rafters can be determined.Granngubben said:
Completely freestanding trusses (ridge beam is not an option) would of course be the best, but then I would have to go up to a 35-degree external slope and I prefer not to.
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As mentioned, a ridge beam is not an option because I want the entire upper floor to be one open (15x8m) loft.
A glulam beam of 15m with two support points would probably be 2m high or something like that
not to mention how I would handle all the tens of tons coming down on the two pillars.
A glulam beam of 15m with two support points would probably be 2m high or something like that
not to mention how I would handle all the tens of tons coming down on the two pillars.Okay, had missed that it was the entire length of the house, without partition walls...
#23:
I suppose the actual advantage of building only in timber and not board is the length. If one were to make these beams oneself by making strips of k-plyfa, how would you make the joint then? Perhaps you could lay two layers offset at 244/2=122 cm? Of appropriate thickness. And order top and bottom parts for the "I-beam" from a local carpentry shop from milled grooves, which are a bit delicate, so that you first have to fill with glue, then knock the sandwich into the groove...
Maybe this gives a better result than a self-built beam in timber? Or attach the strips on the outside as someone else suggested, one on each side of the top and bottom...
If it turns out that the wall does not withstand the bending moment at the joist, maybe post the wall at c-c 30?
Alternatively, screw glue double studs at cc 60...
Well, just brainstorming a little...
PS.
I don't think that's a scissor truss, even though many call them that..
I think more of two truss beams leaning against each other...
DS
#23:
I suppose the actual advantage of building only in timber and not board is the length. If one were to make these beams oneself by making strips of k-plyfa, how would you make the joint then? Perhaps you could lay two layers offset at 244/2=122 cm? Of appropriate thickness. And order top and bottom parts for the "I-beam" from a local carpentry shop from milled grooves, which are a bit delicate, so that you first have to fill with glue, then knock the sandwich into the groove...
Maybe this gives a better result than a self-built beam in timber? Or attach the strips on the outside as someone else suggested, one on each side of the top and bottom...
If it turns out that the wall does not withstand the bending moment at the joist, maybe post the wall at c-c 30?
Alternatively, screw glue double studs at cc 60...
Well, just brainstorming a little...
PS.
I don't think that's a scissor truss, even though many call them that..
I think more of two truss beams leaning against each other...
DS
Thank you for the feedback,
The biggest advantage of using standard wood studs is simplicity and price. If I involve any carpentry, I might as well buy kerto directly, or set up 220x45 at c-c 300.
Regarding the outer wall, both of your suggestions work, but considering the insulation job, it might be easiest to go up to 195x45 as standing studs if needed.
Regarding the naming of the trusses, two trusses leaning against each other become a form of scissors truss. I believe my solution with a 5-degree difference could be classified as self-supporting with a lightweight roof and snow zone 1-2, perhaps, but they can't handle snow zone 3, which we have up here.
It remains to be seen whether an expert can calculate the entire load case and confirm or deny if my theories are correct. In the worst case, I'll have to accept a steeper angle than 30 degrees externally.
The biggest advantage of using standard wood studs is simplicity and price. If I involve any carpentry, I might as well buy kerto directly, or set up 220x45 at c-c 300.
Regarding the outer wall, both of your suggestions work, but considering the insulation job, it might be easiest to go up to 195x45 as standing studs if needed.
Regarding the naming of the trusses, two trusses leaning against each other become a form of scissors truss. I believe my solution with a 5-degree difference could be classified as self-supporting with a lightweight roof and snow zone 1-2, perhaps, but they can't handle snow zone 3, which we have up here.
It remains to be seen whether an expert can calculate the entire load case and confirm or deny if my theories are correct. In the worst case, I'll have to accept a steeper angle than 30 degrees externally.