Member
· Västra götaland
· 104 posts
Hello everyone!
We have just finished casting our wall (1.5 meters high at its highest) on which the house will stand.
It's a tiered solution that follows the slope of the rock at about 12 degrees.
The next step is to fill the wall with draining material (crushed rock and gravel) so we can cast a conventional slab on top (with EPS insulation and edge elements).
The construction of the house is based on a steel beam frame (to avoid load-bearing interior walls). The pillars on which the beams rest should stand quite close to the cast wall but not directly on it.
Before I fill with stone, I thought there is no better anchor than directly to the rock for these pillars.
Should I let these pillars go straight through the slab, straight through the stone, all the way down to the rock?
The alternatives are to cast a pillar (about 0.7x0.7 meters) at the height of the wall and place the beams there instead, or to lay XPS insulation on the finished "ground" at the wall's height and place the beams on top of that.
The downside is having a continuous thermal bridge in steel directly from the rock into the house.
Another possible impact is that the beam becomes about 1.5 meters longer than calculated - I don't know how this affects structural integrity.
Any smart input on this?
Best regards, Richard
We have just finished casting our wall (1.5 meters high at its highest) on which the house will stand.
It's a tiered solution that follows the slope of the rock at about 12 degrees.
The next step is to fill the wall with draining material (crushed rock and gravel) so we can cast a conventional slab on top (with EPS insulation and edge elements).
The construction of the house is based on a steel beam frame (to avoid load-bearing interior walls). The pillars on which the beams rest should stand quite close to the cast wall but not directly on it.
Before I fill with stone, I thought there is no better anchor than directly to the rock for these pillars.
Should I let these pillars go straight through the slab, straight through the stone, all the way down to the rock?
The alternatives are to cast a pillar (about 0.7x0.7 meters) at the height of the wall and place the beams there instead, or to lay XPS insulation on the finished "ground" at the wall's height and place the beams on top of that.
The downside is having a continuous thermal bridge in steel directly from the rock into the house.
Another possible impact is that the beam becomes about 1.5 meters longer than calculated - I don't know how this affects structural integrity.
Any smart input on this?
Best regards, Richard
I think it seems better in several ways to build a crawl space rather than laying a slab. Then you get a storage space under the house and it becomes easier to access pipes and other things. A joist floor should also be cheaper.
I can't really visualize the different solutions. But my initial reaction is that you must have a completed structural drawing for the pillars for the steel beams? It is at least as important to have a correct strength calculation for the posts and their foundation as it is to calculate the beam construction itself.
You mention that the beam is 1.5 m longer than planned. If you mean the post, then this could be critical for buckling. Buckling is more about the relationship between the post's length and geometry than the material's strength. But if it has lateral support where it passes through the slab, I believe the length below the slab can be excluded from the buckling calculation. However, if it is a horizontal beam that has a 1.5 m longer span, then that is a big difference, and the calculations need to be redone.
You mention that the beam is 1.5 m longer than planned. If you mean the post, then this could be critical for buckling. Buckling is more about the relationship between the post's length and geometry than the material's strength. But if it has lateral support where it passes through the slab, I believe the length below the slab can be excluded from the buckling calculation. However, if it is a horizontal beam that has a 1.5 m longer span, then that is a big difference, and the calculations need to be redone.
Member
· Västra götaland
· 104 posts
Hello everyone!
@Pelpet - I have evaluated the crawl space and realized that the bedrock comes too close in many places to be able to make good insulation. Besides that, it's quite damp as water seeps up from the bedrock. I don't want to end up in a situation where I have to install an expensive moisture monitor solution to control what I see as a non-issue.
The alternative for me would be filigree, but it is a much more expensive solution than filling up.
@Hempularen - As you said, there are vertical support pillars for the steel beams, yes. - Yep, I have a construction drawing that assumes the pillars are X long, now I was thinking that in such cases one could extend this by 1.5 meters to ensure the pillar stands firmly down in the ground.
Of course, I have to discuss this with the constructor.
But my question really is whether it's unwise from a thermal bridge perspective as the cold is transported directly from the bedrock up into the house.
Grateful for the answers!
Best regards, Richard
@Pelpet - I have evaluated the crawl space and realized that the bedrock comes too close in many places to be able to make good insulation. Besides that, it's quite damp as water seeps up from the bedrock. I don't want to end up in a situation where I have to install an expensive moisture monitor solution to control what I see as a non-issue.
The alternative for me would be filigree, but it is a much more expensive solution than filling up.
@Hempularen - As you said, there are vertical support pillars for the steel beams, yes. - Yep, I have a construction drawing that assumes the pillars are X long, now I was thinking that in such cases one could extend this by 1.5 meters to ensure the pillar stands firmly down in the ground.
Of course, I have to discuss this with the constructor.
But my question really is whether it's unwise from a thermal bridge perspective as the cold is transported directly from the bedrock up into the house.
Grateful for the answers!
Best regards, Richard