Hemp House-Asheville, NC revisited-Video explaining hempcrete’s use
This video from 2009 is an interesting reminder of the simplicity and yet the brilliance of the hempcrete technology. It is also great for learning about the construction techniques that were used when building the hemp house. Remember the video is about building a house out of hemp. The sustainability will come when people like Obama legalize hemp for industrial use and we can grow it here in the USA.
Enjoy the video and learn more about the properties hemp-technologies’s hempcrete below it. We have posted all the good stuff there!!!
Hemp Video description: Constructing the first permitted home in America built primarily of hemp materials, Hemp Technologies’ crew forms 12″ walls in a monolithic pour. No Blocks were used on this house.
Why We Like Hempcrete
The goal of environmentally conscious building design is to create buildings that create a healthy indoor environment while supporting a healthy outdoor environment. The best way to accomplish this goal is through combining cutting edge building science with what are commonly called “natural building” practices. High performance building science allows us to create buildings that use almostno energy to run, therefore reducing the size and price of the renewable energysystem required to produce on site all the energy required to run the building.The natural building perspective helps us utilize natural, local, and site-harvestedmaterials that have a very low embodied energy, therefore lowering the carbonand pollution footprint of the building during construction. Together, these twostrategies allow us to reach the threshold of carbon neutrality, a building thatdoes not contribute to our current climate change problems.On the natural building side, we feel that earthen mixes don’t have adequatethermal performance while the vulnerability of straw bales to water damageconcerns us. On the high-performance commercial side, we are skeptical of thelong-term durability of SIPS walls and feel that double stick frame systems aretoo complex and prone to air infiltration weaknesses. These and other problemshave been solved by what to us is a new material: Hempcrete.Hempcrete is a mixture of industrial hemp shiv and lime-based binder. Whenused in walls, it is either spray applied or placed in forms in or around a skeletalstructure, such as a timber or steel frame. The resulting wall system has many ofthe benefits of common natural building applications, such as straw bale or clayslipstraw, with the quality control of mass-production and the durabilityprovided by coating cellulose with lime. Some of the benefits of Hempcrete forour application are:
1. High thermal resistance.
The normal Hempcrete mix has an R-valueof 2.4 per inch. This is superior to straw bale construction and any earthand straw mix. Due to reduced thermal bridging, it is also most likelysuperior on a per inch basis to conventional stick frame systems withcellulose or fiberglass insulation.
2. Adjustable thickness.
Though Hempcrete is presently not considered astructural material it is strong enough to constitute the interior andexterior substrate for finishing materials. This means that the thickness ofa Hempcrete wall is adjustable independent of the thickness of structuralwall members. Therefore, a Hempcrete wall can be adjusted to meet thethermal requirements of any given climate.
3. Low air infiltration.
Hempcrete is a relatively dense material thateither surrounds or sits in front of or behind the structural system of awall. This means that a Hempcrete wall will be inherently quite air-tight.Low air infiltration is a pivotal component of our performance strategy.
4. Hygroscopic characteristics.
In building, a “hygroscopic material” issomething that can absorb water. Lime and Cellulose, in this case HempShiv, work together to create a wall that can take on and give off water inresponse to changing humidity levels in the air. This is called a “breathablewall” system and is a great boon to indoor air quality and wall durability.Plastered straw bale walls are “breathable” in this way. The lime inHempcrete will protect the hemp from molding, therefore creating abreathable wall that can be part of a healthy indoor air strategy in a humidclimate.
5. Substrate for lime and earth plasters.
Hempcrete is a great substratefor earth and lime plasters. No manufactured laths or synthetic vaporbarriers are required. This greatly simplifies construction, reducing laborand material costs for plastering.
6. Accommodates different structural systems.
Our preference is tobuild structures that will last many hundreds of years. Our approach fordoing this is to create a post and beam structure using masonry columnsand wooden beams. This system requires an insulation material thatwraps the exterior of the structural members and therefore must be able tostand up on its own. Hempcrete can do this. At the same time, thisstructural system is more expensive, so for smaller budgets we need to beable to use a simpler structure. Hempcrete also works well with thesimplest structural system around: the wooden stick-frame.
7. Durable and Recyclable.
Hempcrete will create a very durable wall.However, when the building lifecycle has finally come to an end,Hempcrete can be re-used, either as a building material or perhaps a soilamendment. Regardless, there will be no reason to take it to a land fill;something that can’t be said for most modern materials.
8. Beauty, of course!
People respond very positively to thick walls and roughplastered finishes. It seems to us that this combination is an aestheticarchetype. Hempcrete delivers this aesthetic not as an add-on orafterthought, but as an inherent part of its form.
Don’t forget to check out the awesome crew and additional information over at Hemp-technologies.com. And YES you can buy hempcrete!