Hempcrete — Rethinking Building Materials for a Fire-Prone Future

Course: Lifelong Learning

Instructors: Ms. Tunzi & Ms. Kicak, Co-Owners, Fancy Farmerettes Ltd.

Date: July 19, 2026

Topic: HEMPCRETE - Rethinking Building Materials for a Fire-Prone Future

Welcome to class! Between teaching by day and running the Fancy Farmerettes micro-farm by night, we spend a lot of time looking at how things are built. Right now, there are over 130 active wildfires burning across Northern Ontario. Actual news reports show the wind is blowing that heavy smoke straight down into Southern Ontario, turning the skies a hazy orange. It is even triggering major air quality alerts as far south as the US Midwest and Northeast, where the air has reached levels that are unsafe for everyone to breathe. With the increase in forest fires in North America, we cannot keep building houses out of materials that act like firewood. It is time to look at a solution that grows right out of the dirt!

1. Minds On: The Wildfire Problem & The Hempcrete Solution

• The Problem: Normal home building uses a lot of wood, plastic foams, and vinyl. In a wildfire, these materials catch fire easily and give off poisonous smoke. Globally, researchers note that modern building practices rely heavily on materials with huge carbon footprints that fail completely under extreme heat.
• The Alternative: Hempcrete (sometimes called "hemp-lime") is a natural building material that does not hold up the house like normal concrete but rather fills the walls to keep the house warm and let it breathe. In places like Europe, builders have successfully used this natural mix for decades to restore old buildings and build healthy new homes.
• The Recipe: It only needs three simple ingredients: hemp hurd (the chopped up, woody inside of the hemp plant), a natural rock powder called lime binder, and water. Nationally, Canadian farmers are growing more of this crop because the deep roots help fix our soil while the stalks are sold to green builders.

Hemp hurd mixed with lime binder. Source: IND HEMP

• The Carbon Win: Hemp is one of the fastest-growing plants on earth, absorbing up to 15 tonnes of CO2 gas per hectare. Recent studies show that replacing standard materials with hemp-based blocks can actually make a home "carbon negative," meaning it locks away more pollution than it takes to build.

2. Action: Science of Fire Resistance, Industry Pushback & Our Coop

• Why doesn't a plant-based wall burn: The magic is in the science, where the lime powder fully wraps around every single piece of chopped hemp. International testing shows that the high breathability of the blocks allows heat and moisture to safely escape instead of trapping it inside the walls.
• Turning to Stone: When hit by the super high heat of a wildfire, the lime hardens and turns back into solid limestone rock. As the lime heats up, it triggers a chemical reaction that creates a rock-solid barrier against the flames.
• The Char Layer: Instead of catching fire, the outside of the wall turns black and forms a protective "char" layer that blocks the heat from moving to the inside. This means the inside of the home stays cool and safe, giving families vital time to shelter or escape during a crisis.
• The Proof: In strict fire tests, a normal hempcrete wall can take a 1700°F (926°C) direct blowtorch flame for over an hour with no fire spread and no poisonous smoke. In fact, recent fire tests on homes in British Columbia and the US have proven these walls meet strict two-hour fire ratings without falling down. ▶ Watch the torch test video here

• The Pushback Against the Status Quo: Why is the building industry fighting against using hempcrete as the new normal? Right now, hempcrete is still seen as an "alternative" material and is not formally written into the National Building Code of Canada. This means builders have to jump through expensive hoops to get special engineers to sign off on their plans, and many tradespeople simply are not trained in plastering with natural lime instead of slapping up cheap drywall.
• The Fancy Farmerettes Project: We practice what we teach and are currently designing a state-of-the-art hempcrete wall upgrade to replace the main coop for our flock of 40 birds. This lets us test the safety and strength of the blocks on our own farm before we recommend them to our agricultural community.
• Sourcing the Build: While we sell the raw hemp hurd out of Norfolk County as commercial distributors, we do not make building blocks ourselves, so we are currently looking for ready-made, pre-cast hempcrete blocks to build this new modular coop. Finding pre-made blocks will save us weeks of drying time compared to mixing and packing wet hempcrete by hand into wall frames.
• Our Design Plans: We will use pre-cast hempcrete walls to give the birds the best protection from disease and extreme weather, while using a custom sloped floor design for heavy washing. By connecting the central floor drain directly to the open French drain network already sitting on our 1.2-acre Scotland property, we ensure the hemp walls stay perfectly dry at the base while keeping the flock clean.

3. Wrap Up: Where to Buy & Required Reading

If we want to survive future fire seasons, the Canadian building industry needs to change its rules and adopt this material. Here is where to find it and the research that backs it up.

Where to Source Canadian Hempcrete:

• Hempcrete Homes Inc.: A company in Alberta that makes ready-to-use hempcrete blocks and large wall panels.
• Hemp Tek Builder: Builders in Ontario who use hempcrete technology to build eco-friendly homes.
• Hempitecture: A North American supplier that sells fireproof lime powders and hemp insulation that meet strict safety rules.

Annotated Bibliography (Recent Research 2024–2026):

CTV News. (2026). "Toronto air quality roughly five times worse than day prior as wildfire smoke builds." CTV News.

A national Canadian news report tracking how smoke from active wildfires in Northern Ontario moved into Southern Ontario and into the US. It shows how traditional building materials and communities are directly threatened by extreme weather patterns spreading across borders.

Climate Solutions. (2026). "Hempcrete Extended Factsheet." Climate Solutions Canada.

A national report breaking down why the current building industry is resisting hempcrete. It explains the major challenges with Canadian building codes, how hard it is to get permits without special engineers, and the lack of trades workers trained in natural materials.

Johnson, A. (2025). "This fire-resistant hemp-based mixture aims to protect homes from B.C. wildfires." CP24.

A regional news report about a house built in Lumby, B.C., using hempcrete specifically because it has a two-hour fire rating. It shows a real Canadian example of how these walls act like armor against wildfires without giving off bad chemicals.

Construction Magazine. (2025). "How to disrupt the status quo when it comes to building materials."

An industry article detailing why builders must stop relying on normal cement and plastic foams. It proves that hempcrete blocks are completely carbon negative and can manage indoor moisture naturally without the need for toxic chemicals.

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