Hempcrete. Helping to Build a Sustainable Future

Hempcrete may be the perfect material for your building project if you are looking for a healthy and comfortable home with environmental sustainability at its core.

Hempcrete Uses

When combined with a timber or steel frame construction as the load-bearing structure, hempcrete can be cast between formwork and used to build monolithic walls that provide a natural, sustainable, insulated structure. Hempcrete can also be cast in situ against existing timber frames or solid walls. It can also be cast between joists to insulate suspended floors and between rafters as roof insulation.

What is Hempcrete?

Hempcrete is a mix of Lime and Hemp Shiv (also known as Hemp Hurds). NHL Lime is combined with hemp for building. There are also various lime-based binders developed specifically for hempcrete which set quicker and stronger. Hempcrete that has been made with a Hemp Binder is less likely to slump or move when the formwork is removed. An operation is required soon after casting to allow the walls to dry out. We recommend the Limegreen Hemp Binder developed and manufactured here in the UK.

The Environmental Benefits of Hemp

Industrial Hemp is a fantastic material, offering a host of environmental benefits: 

• Hemp Shiv (or hurd. The part of the hemp plant used in Hempcrete) is the woody core and a bi-product of hemp oil, seed and fibre production. 
• Hemp grows in different climates and soil types offering opportunities to a wide demographic of growers. 
• Hemp is naturally resistant to pests. 
• The Hemp crop grows quickly. It out competes weeds and avoids the need for weed killers. When grown in rotation, it leaves weed-free land for the next crop. 
• One hectare of hemp will sequester 8 to 15 tonnes of CO2. A similar to the amount sequestered by a young forest, but it only takes five months to grow. 
• Hemp plants flower between July and September and provide a large amount of pollen for bees and insects. Hemp is a tall crop and therefore also provides shelter for birds. 
• Other environmental benefits can be found in our "Reasons we love hemp" blog post. 

The Benefits of Building with Hempcrete 

• When used in construction, the hemp locks away carbon (CO2) into the structure of the building. 
• Hempcrete is reusable and/or biodegradable at the end of the building's life. 
• Hempcrete is around eight times lighter than concrete. 
• Hemp is Hygroscopic, a property of natural fibres. It helps to equalise humidity levels by locking away moisture when humidity is high and releasing the moisture as vapour when humidity levels drop. 
• Hempcrete does not off-gas or release any toxins into the environment. 
• The Lime used as the binder in hempcrete is naturally antifungal. It kills bacteria and is mould resistant. 
• The mineral coating of lime around each piece of hemp, adds a high level of flame resistance.
• Hempcrete stores heat due to its thermal mass, which is released slowly into the building even when the external temperature has dropped. 
• Hempcrete is more flexible than concrete which means no expansion joints are required.

And if that isn’t enough to convince you of the benefits of hempcrete, imagine a winter's evening sat in front of the TV, a cup of something comforting in your hands, and the warm, natural hemp walls gently radiating heat back into the room. And relax.

If you would like to discuss this amazing material with one of our knowledgeable staff please contact us.