I absolutely love the idea of hempcrete. I believe it is non-structural, though, and requires framing if it goes to any height - rather like a half-timbered building. I stayed iin a 450-year-old half-timbered house for a couple of weeks once, courtesy of the wonderful Landmark Trust. It was a very cold December, and the plastering had all shrunk away from the beams, leaving gaps of up to an inch through which the wind whistled, and through which we could see the black night sky. We froze! Is that a known issue with hempcrete?
The traditional materials builders I know and learn from are very particular about avoiding shrinkage - there is a lot of testing of materials and experimenting with recipes before finalising the mix for any particular build. Shrinkage rates depend on the characteristics of the clay and can be amended by adding chopped straw, paper pulp, sand etc. I'm pretty excited about low adobe brick, a material pioneered in New Zealand. Much easier to work with, load bearing and capable of meeting New Zealand's stringent standards for withstanding earthquakes. I agree that hemp is an amazing plant with many uses but weirdly, many proponents of hempcrete seem to not understand hemp is just one of many fibres that can be mixed with binders to produce a great building material; theirs is an adaption not a blinding new innovation. (There is also a big division, in my country at least, between builders who use cement and lime as binders and those who don't. Hempcrete does use chemical binders and there are drawbacks to that.) I live in a strawbale certified Passive House that has LEM (light earth material) internal walls: https://sustainableengineering.co.nz/casestudy/martins-farmhouse/
This is one of those things that is so obvious when you see it that you wonder how you didn't see it before. That whole comparison of bricks to Stone makes so much sense. Especially the starkness of expending huge amounts of energy to DOWNCYCLE Stone to concrete. Truly bonkers! And I was never a fan of brick and you've just given me one more reason to hate it.
Traveling around Ireland and the UK, especially Scotland and Orkney, I have seen the historical range of uses of stone as building material, from the use of stones essentially as found for walls, roofs, and at Shara Brae for interior furnishings. By the time of the Roman occupation you have the use of worked stone from quarry to building site with skilled craftsmen shaping and fitting stones together, my missing piece is not recalling where the stonemasons ended up economically. Did they price themselves into the high end leaving room for cement workers to undercut them pricewise?
I absolutely love the idea of hempcrete. I believe it is non-structural, though, and requires framing if it goes to any height - rather like a half-timbered building. I stayed iin a 450-year-old half-timbered house for a couple of weeks once, courtesy of the wonderful Landmark Trust. It was a very cold December, and the plastering had all shrunk away from the beams, leaving gaps of up to an inch through which the wind whistled, and through which we could see the black night sky. We froze! Is that a known issue with hempcrete?
The traditional materials builders I know and learn from are very particular about avoiding shrinkage - there is a lot of testing of materials and experimenting with recipes before finalising the mix for any particular build. Shrinkage rates depend on the characteristics of the clay and can be amended by adding chopped straw, paper pulp, sand etc. I'm pretty excited about low adobe brick, a material pioneered in New Zealand. Much easier to work with, load bearing and capable of meeting New Zealand's stringent standards for withstanding earthquakes. I agree that hemp is an amazing plant with many uses but weirdly, many proponents of hempcrete seem to not understand hemp is just one of many fibres that can be mixed with binders to produce a great building material; theirs is an adaption not a blinding new innovation. (There is also a big division, in my country at least, between builders who use cement and lime as binders and those who don't. Hempcrete does use chemical binders and there are drawbacks to that.) I live in a strawbale certified Passive House that has LEM (light earth material) internal walls: https://sustainableengineering.co.nz/casestudy/martins-farmhouse/
Definitely a lightbulb moment
This is one of those things that is so obvious when you see it that you wonder how you didn't see it before. That whole comparison of bricks to Stone makes so much sense. Especially the starkness of expending huge amounts of energy to DOWNCYCLE Stone to concrete. Truly bonkers! And I was never a fan of brick and you've just given me one more reason to hate it.
Traveling around Ireland and the UK, especially Scotland and Orkney, I have seen the historical range of uses of stone as building material, from the use of stones essentially as found for walls, roofs, and at Shara Brae for interior furnishings. By the time of the Roman occupation you have the use of worked stone from quarry to building site with skilled craftsmen shaping and fitting stones together, my missing piece is not recalling where the stonemasons ended up economically. Did they price themselves into the high end leaving room for cement workers to undercut them pricewise?