Why Hempcrete’s Such a Great Insulator

Hempcrete and Insulation

Insulation is an important part of building a business or home. Traditionally, buildings have used a wide variety of materials as an insulator, such as fiberglass or cellulose, but recently, a hemp-based insulation alternative has been growing in popularity. Hempcrete’s renewable nature is changing the way we use insulating materials. As the desire to remain environmentally conscious continues to grow, many contractors around the world are trying to build carbon-neutral houses with the help of hempcrete.


What Does Insulation Do?

Insulation is the reason your house stays cool in summer and warm in the winter. If you did not have insulation, your air conditioning or heater would be forced to run all day. Insulation keeps you comfy when the weather outside is bad. Let’s look at what insulation does.


  • Keeps the right temperature
  • Improves energy efficiency
  • Cuts electricity costs
  • Reduces the amount of heating and cooling you need
  • Stops the collection of moisture
  • Cuts noise
  • Cuts pollutants from going into the air


As you can see, insulation is important when building a home or business.  So, what has made hempcrete such a popular insulation option? The answer is in the material’s composition. It’s made up of a mixture of hemp shivs, lime binders, and water. Each one plays an important part in giving hempcrete its insulative qualities.

What Makes Hempcrete a Good Insulator

The shivs that make up the bulk of hempcrete are woody chunks from the hemp plant, which can soak up lots of water while also keeping their shape. Over time, the extra water evaporates, but this change in humidity does not alter the shape of the material, which contributes greatly to its longevity.

Hempcrete’s longevity is just one thing that makes it a good insulator. Many old materials, like cellulose, fiberglass, and wool, can make people sick. These materials also lose their ability to insulate if they get wet. Cellulose, in particular, soaks up water really easily, making it a poor insulator. Fiberglass does not soak up water, but it is a potential health hazard.


On the other hand, the small pores of hemp shivs allow moisture to pass through it, and the lime binder contributes greatly to hempcrete’s thermal mass—the term that shows how much heat a building can retain during sudden temperature changes. Hempcrete’s rise in popularity is helping to evolve how buildings are insulated, reducing their carbon footprints.

Insulation is not just about maintaining a pleasant temperature within a home. It’s about sound, too. Because hempcrete is such a good insulator, it helps in places like apartment buildings where noise can be a problem. And while rude neighbors can certainly make a lot of noise, so can freeways, street traffic, and foot traffic.


One study showed that using a hempcrete wall guarded against the sounds of a freeway. The study also found that hempcrete insulated well because it can resist all kinds of weather, including high moisture.

Potential Insulation Problems with Hempcrete

While you certainly could create your own hempcrete at home, it’s typically a better idea to buy premade blocks. When mixing it yourself at home, you must be extra cautious that you use the proper amounts of hemp shiv, lime binder, and water. If any of these parts are too high or too low, the total thermal mass will change. This guide shows that great care must be taken when pressing the hempcrete down, or you could destroy the micro-pores found in the hemp shiv.


However, well-made hempcrete blocks—either purchased from a retailer or made yourself at home—will benefit your home greatly when used as an insulative material. It’s cost-effective, highly efficient, and will help the environment.