5 ms·

You can probably do that already without this material. Glued laminated timber is already a pretty good material for such cases.

by tapia 1y ago

mschild 1y ago
Absolutely, its unfortunately just a matter of cost. To get an equally sized wood beam that could support the weight, its almost 5x the price. Even factoring in other materials and labour.
- kragen 1y ago
  Are you saying that wood is 5× the price of steel, or that glu-lam is 5× the price of wood?
  - mschild 1y ago
    The total cost of replacement as quoted to me by contractors is 5x. I've reached out to several and none of the quotes go below it. I'm doing a lot of things myself, but anything that can get dangerous or wildly expensive when I fuck it up I let skilled contractors handle.
    - kragen 1y ago
      That's even less clear. The total cost of replacing what with what is 5× what? I think what you want to remove is steel beams, but I'm not even sure of that.
      - mschild 1y ago
        I have to replace a steel beam inside my house. It's old and when it was installed (1936), the building and load requirements were quite a bit different. With the modifications I'm making to the house, a new one is needed. The beam runs across the ceiling in my living and dining room. Previous owners installed a lowered drywall ceiling to hide it but that took 20cm of height from the rooms. I'd like wood beams because I could leave this exposed in the room as a design element and have 20cm more ceiling height. I would not want to see the steel beam (even the new one). For the entire replacement, including labour, materials, and anything else to have a finished ceiling, the quotes I received from multiple contractors are all at least 5x more expensive for the wooden beams. This may ultimately not be down to the cost of the beam itself but rather that partial wooden construction is newer trend in Germany and they can simply ask for more but I don't have confirmation for that.
        kragen 1y ago
        So the total building project becomes 5× more expensive if you use wood beams than if you get a new, thicker steel beam with a new lowered drywall ceiling over it? Where does the glu-lam alternative come in?
- jillesvangurp 1y ago
  CLT is not inherently more expensive and the cost difference is typically less dramatic. Steel just has a few centuries of a head start on learning curves, economies of scale, etc. Scaling up usage of CLT would bring down cost just like it has with steel. The biggest issue actually is that there's a lot of resistance in the construction industry that is simply locked into using steel and concrete and more or less blind to the advantages of wood. Switching materials would mean new tools, new skills, etc. are needed. I have a friend who is active in Germany pushing the use of this material and he talks a lot with companies in this space. Companies seem to default to doing what they've been doing for a long time without considering alternatives. Many construction projects are actually still one-off projects that don't leverage economies of scale or learnings from previous construction projects. Construction could be a lot cheaper and much less labor intensive than it is today. CLT could actually make on-site assembly a lot simpler and faster than it is today. Ship pre-fab components created in large scale facilities optimized to manufacture those cost effectively. Assemble on site using simple tools and processes.
  - ffsm8 1y ago
    I don't work in the industry, but from my admittedly very consumer-oriented perspective that wanted to build a house for a while: The reason why economics of scale never really made sense in this context was that shipping the prefab components to the building site mostly wiped out the savings. Ignoring the actual shipping cost (which is substantial for heavy things that get assembled into a house), it also comes with the risk of things getting damaged while en-route etc. another reason is the fact that places in reality very rarely are actually the same. They can do best effort, but things will likely still vary a little. That's another error scenario wiping out a good chunk of the savings, which fundamentally doesn't exist of you just build on-site. I'm not knowledgeable on this new material to judge wherever this could potentially change this status-quo, but I wouldn't hold my breath either.
    - jillesvangurp 1y ago
      I think the concerns you raise aren't actually show stoppers for a lot of prefab housing that has been happening for decades. Wood is a lot lighter than steel and concrete. And that has to be transported as well. So you'd have less cost there, not more. About 50% weight savings. That's a lot of diesel. As for parts getting damaged. That's what insurance an warranty are for. I don't think that's a show stopper issue. And there are advantages to producing prefab components in a facility that is optimal for that and climate controlled that has all the right tools, specialists, equipment etc. Also, pooring concrete in the winter is problematic. Water freezes. And it expands when it does so. Working with steel is a PITA when it freezes as well. It conducts heat very well. Construction sites aren't very active in the winter in those places that have them for this reason. Prefab wood components don't have a lot of these issues. You can still work wood when it freezes. And bang in some nails. Or drill holes.
- tapia 1y ago
  Yes, the Glulam alternative tends to be a bit more expensive for some applications, but I am surprised that it is 5x more expensive than the steel solution. The reference I have (in Europe at least) is that the cost of Glulam is currently about 350 €/m³. Steel is quite more expensive, but of course, the profiles are slender, so less material is used.

You can probably do that already without this material. Glued laminated timber is already a pretty good material for such cases.

by tapia 1y ago

You can probably do that already without this material. Glued laminated timber is already a pretty good material for such cases.

mschild 1y ago

Absolutely, its unfortunately just a matter of cost. To get an equally sized wood beam that could support the weight, its almost 5x the price. Even factoring in other materials and labour.

kragen 1y ago
Are you saying that wood is 5× the price of steel, or that glu-lam is 5× the price of wood?
- mschild 1y ago
  The total cost of replacement as quoted to me by contractors is 5x. I've reached out to several and none of the quotes go below it. I'm doing a lot of things myself, but anything that can get dangerous or wildly expensive when I fuck it up I let skilled contractors handle.
  - kragen 1y ago
    That's even less clear. The total cost of replacing what with what is 5× what? I think what you want to remove is steel beams, but I'm not even sure of that.
    - mschild 1y ago
      I have to replace a steel beam inside my house. It's old and when it was installed (1936), the building and load requirements were quite a bit different. With the modifications I'm making to the house, a new one is needed. The beam runs across the ceiling in my living and dining room. Previous owners installed a lowered drywall ceiling to hide it but that took 20cm of height from the rooms. I'd like wood beams because I could leave this exposed in the room as a design element and have 20cm more ceiling height. I would not want to see the steel beam (even the new one). For the entire replacement, including labour, materials, and anything else to have a finished ceiling, the quotes I received from multiple contractors are all at least 5x more expensive for the wooden beams. This may ultimately not be down to the cost of the beam itself but rather that partial wooden construction is newer trend in Germany and they can simply ask for more but I don't have confirmation for that.
      - kragen 1y ago
        So the total building project becomes 5× more expensive if you use wood beams than if you get a new, thicker steel beam with a new lowered drywall ceiling over it? Where does the glu-lam alternative come in?
jillesvangurp 1y ago
CLT is not inherently more expensive and the cost difference is typically less dramatic. Steel just has a few centuries of a head start on learning curves, economies of scale, etc. Scaling up usage of CLT would bring down cost just like it has with steel. The biggest issue actually is that there's a lot of resistance in the construction industry that is simply locked into using steel and concrete and more or less blind to the advantages of wood. Switching materials would mean new tools, new skills, etc. are needed. I have a friend who is active in Germany pushing the use of this material and he talks a lot with companies in this space. Companies seem to default to doing what they've been doing for a long time without considering alternatives. Many construction projects are actually still one-off projects that don't leverage economies of scale or learnings from previous construction projects. Construction could be a lot cheaper and much less labor intensive than it is today. CLT could actually make on-site assembly a lot simpler and faster than it is today. Ship pre-fab components created in large scale facilities optimized to manufacture those cost effectively. Assemble on site using simple tools and processes.
- ffsm8 1y ago
  I don't work in the industry, but from my admittedly very consumer-oriented perspective that wanted to build a house for a while: The reason why economics of scale never really made sense in this context was that shipping the prefab components to the building site mostly wiped out the savings. Ignoring the actual shipping cost (which is substantial for heavy things that get assembled into a house), it also comes with the risk of things getting damaged while en-route etc. another reason is the fact that places in reality very rarely are actually the same. They can do best effort, but things will likely still vary a little. That's another error scenario wiping out a good chunk of the savings, which fundamentally doesn't exist of you just build on-site. I'm not knowledgeable on this new material to judge wherever this could potentially change this status-quo, but I wouldn't hold my breath either.
  - jillesvangurp 1y ago
    I think the concerns you raise aren't actually show stoppers for a lot of prefab housing that has been happening for decades. Wood is a lot lighter than steel and concrete. And that has to be transported as well. So you'd have less cost there, not more. About 50% weight savings. That's a lot of diesel. As for parts getting damaged. That's what insurance an warranty are for. I don't think that's a show stopper issue. And there are advantages to producing prefab components in a facility that is optimal for that and climate controlled that has all the right tools, specialists, equipment etc. Also, pooring concrete in the winter is problematic. Water freezes. And it expands when it does so. Working with steel is a PITA when it freezes as well. It conducts heat very well. Construction sites aren't very active in the winter in those places that have them for this reason. Prefab wood components don't have a lot of these issues. You can still work wood when it freezes. And bang in some nails. Or drill holes.
tapia 1y ago
Yes, the Glulam alternative tends to be a bit more expensive for some applications, but I am surprised that it is 5x more expensive than the steel solution. The reference I have (in Europe at least) is that the cost of Glulam is currently about 350 €/m³. Steel is quite more expensive, but of course, the profiles are slender, so less material is used.