Mixing hempcrete

As with all types of construction, personal protection equipment is always the first consideration when working with hemp and lime. This first episode will cover the personal protection required when mixing hempcrete. Additionally, we’ll talk about how we combine processed hemp hurd, with a hydrated lime binder, and water to get our hempcrete material mix. Hempitecture recommends using a high calcined hydrated lime, often in conjunction with a mineral additive for a faster set.

Mixing RATIO

Generally, a 4:1:1 volume ratio of hemp hurd to lime to water is appropriate. There are many kinds of mixers that can be used, but on this project we used a vertical shaft pan mixer. It has a higher cubic ft capacity relative to smaller drum or mortar mixers.

Once the mix is the right consistency, after about 5 minutes of mixing, we take the material to the wall. Every project is different, and there may be different mixing strategies, binding agents, and ratios that work best for your location and climate.

This instructional video shows the personal protection and mixing procedures for a hempcrete building project in the Pacific Northwest. Thanks to hempitecture for their amazing videos and overall inspiration as a hemp company. View more on hempitecture here

Evo Hemp’s video below is also a great introduction on mixing hemp.