A Better Way to Build

Hempcrete is a bio-composite, non-structural, insulation infill material made of hemp hurd fiber (the strong inner stalk) and a lime-based, mineral binder.

The many benefits of hempcrete construction include energy efficiency, utility cost reduction, high thermal/insulation performance, low embodied energy and carbon emissions in production, carbon sequestration in use, fire and mold resistance, and healthy indoor air quality.

The line of hempcrete blocks manufactured by Hemp and Block are designed to meet or exceed all quality standards and expectations for use in hempcrete (hemp-lime) construction, as
outlined in the 2024 International Residential Code Appendix BL for Hempcrete. This includes being lightweight, low-density, and non-structural.

The typical compressive strength of proper hempcrete, in the USA and Europe, is in the range of only 40-100 psi. Strong enough to be self-supporting for building up walls but not intended to carry full structural loads.

Hempcrete is intended to be used as a high-performance and sustainable replacement for multiple conventional wall materials: drywall, latex paint, fiberglass insulation, plastic wrap, OSB/plywood, and siding for example. It can also be used to insulate floors and attics.

Use hempcrete insulation for new construction or energy efficient renovation projects on existing homes and buildings. For non-structural use in external and internal walls, floor and ceiling
insulation and more. Creates a thermal building envelope for walls that “breathe” (are vapor permeable). Acts as substrate for applying a lime-based plaster or render wall finish. Replaces
drywall, fiberglass insulation, sheathing, plastic wrap and more with a simple, natural, and beautiful form of sustainable masonry.

Hempcrete blocks are off-white/beige to gray in color and have a unique, choppy hemp texture. They are lightweight (12.5 – 25 lbs. / cubic foot) and strong enough to be self-supporting for building walls. Highly insulating with an R-value of 2 for every inch depth of hempcrete (varies based on density). Installation is simple, using lime mortar (hempcrete binder + sand and/or hemp fiber) to lay blocks.

Hempcrete can be finished with many options including: lime or clay-based plaster/render, limewash or masonry paint, wood siding, cladding, stone or veneer. The key is to provide a
breathable (vapor permeable) finish. In certain applications it’s necessary to provide a ventilation gap between hempcrete and the exterior finish material if it is not breathable.

Using pre-cast blocks allows you to quickly build up hempcrete walls without the extended cure-time delays and increased labor that is common with other methods of installing hempcrete.

The cure time for fresh cast hempcrete mix may take at least 1 week for every inch depth of wall. A 12” wall can take 10-12 weeks or more to cure out, depending on weather and temperature. Finish work like plastering can’t begin until it’s fully cured. But our pre-cast hempcrete blocks arrive to the jobsite ready to install and you can move on to finish work straight away after the mortar sets (generally overnight).

In terms of labor difference, the “tamp-in-place” method can be very tedious and labor intensive. Every square inch of that hemp wall must be compressed in place using tamping rods, manually. Any inconsistency in tamping throughout the project can result in great differences in density, appearance, and insulation throughout the hempcrete wall.

Additionally, great volumes of hemp hurd + hempcrete binder and water must be mixed on site to feed the tamp-in-place construction process. Batching hempcrete at a large scale is a skilled operation and if mistakes are made during mixing, it can lead to major failures.

Hemp and Block uses dedicated block making machinery and qualified personnel to ensure consistency and quality through all batching and production operations. Our block machines do the tamping, so you don’t have to!

And with pre-cast hemp blocks, it’s only necessary to mix mortar on-site for laying the blocks. This is a much smaller material requirement and easier to manage. Laying pre-cast hempcrete
blocks allows you to finish the job much faster with less on-site work.

For performance and sustainability, the Hemp and Block line of hempcrete blocks are made with only: hemp hurd, hydrated lime, and natural volcano-based pozzolan. All specifically sourced from within the USA to make a true, “low footprint” building material.