Welcome back to our "Hemp Builds" series! If you missed Part 1, we dove into the basics of what hempcrete actually is. Today, we’re getting into the nitty-gritty: how it stacks up against the heavyweight champion of the construction world: traditional concrete.

At Farris General Contracting, we believe in providing our clients with the best options for their specific needs, whether that’s a modern home addition or a ground-up custom home build. As a residential contractor focused on quality craftsmanship construction, we’re seeing more people ask about sustainable alternatives.

Is hempcrete a "concrete killer," or do they just have different jobs to do? Let’s break it down.

The Quick Breakdown: Hempcrete vs. Concrete

Before we dive into the details, here is a high-level look at how these two materials compare in 2026.

Feature	Hempcrete	Traditional Concrete
Primary Use	Insulating walls & infill	Foundations, slabs, & structure
Insulation (R-Value)	High (approx. R-2 to R-3 per inch)	Very Low (approx. R-0.1 per inch)
Carbon Impact	Carbon-Negative (stores CO2)	Carbon-Positive (high emissions)
Strength	Low (non-structural)	High (load-bearing)
Fire Resistance	Naturally high	High
Moisture Control	Breathable (regulates humidity)	Non-breathable (can trap moisture)

1. Insulation and Energy Efficiency: The "R-Value" Reality

When you’re planning a custom home build, energy efficiency is usually at the top of the list. Here’s the big secret: traditional concrete is a terrible insulator.

Concrete has what we call "thermal mass," meaning it can hold heat, but it doesn't stop heat from moving through it. If you have a solid concrete wall, you must add layers of foam or fiberglass insulation to meet modern building codes.

Hempcrete, on the other hand, is a superstar in this department. Because it’s made from the woody core of the hemp plant (the "shiv") mixed with lime, it’s full of tiny air pockets.

• The Insulation Factor: Hempcrete provides about R-2 to R-3 per inch of thickness. A standard 12-inch hempcrete wall gives you an R-value of roughly R-24 to R-36, which is incredible for a single-material wall system.
• Thermal Inertia: It combines insulation with thermal mass. This means your home stays cool in the summer and warm in the winter without your AC unit working overtime.

2. Environmental Impact: Carbon Sinker vs. Carbon Emitter

As a residential contractor, we’re always looking at the long-term impact of the materials we use. This is where the two materials couldn't be more different.

The Problem with Concrete

Traditional concrete relies on Portland cement. The process of making cement involves heating limestone to extreme temperatures, which releases massive amounts of CO2. In fact, cement production alone is responsible for about 8% of global CO2 emissions. For every ton of cement produced, roughly one ton of CO2 is released into the atmosphere.

The Hempcrete Advantage

Hempcrete is what we call "carbon-negative."

1. During Growth: While the hemp plant is growing, it sucks up a huge amount of CO2 from the air: faster than most trees!
2. During Curing: Once the hempcrete is placed in your walls, the lime binder continues to "re-carbonate" over several decades, pulling even more CO2 out of the air as it turns back into stone.

When you choose hempcrete for your remodel or new build, you aren't just reducing your footprint: you're actually locking carbon away inside your walls.

3. Structural Strength: Where Concrete Still Wins

We have to be honest here: Hempcrete is not a direct replacement for concrete when it comes to strength.

If you are pouring a foundation, a driveway, or a structural slab, you’re still going to need traditional concrete. Concrete has incredibly high "compressive strength," meaning it can hold up the entire weight of a multi-story building.

Hempcrete is much softer and lighter. If you tried to build a foundation out of it, it would eventually compress or crack under the weight of the house. That’s why in quality craftsmanship construction, we use a "hybrid" approach:

• Concrete for the foundation and the slab.
• A Timber or Steel Frame for the structural "bones" of the house.
• Hempcrete to "infill" the walls, providing the insulation and the enclosure.

4. Durability and Health: Breathability Matters

Have you ever noticed that "basement smell" in older concrete homes? That’s often caused by moisture getting trapped against the concrete, leading to mold and mildew. Concrete is "vapor-impermeable," which means it doesn't breathe.

Hempcrete is "vapor-permeable." It acts like a natural humidity regulator. When the air inside your home is too humid, the hempcrete absorbs the extra moisture. When the air gets too dry, it releases it back. This creates a much healthier indoor environment and completely eliminates the risk of hidden mold growing inside your walls.

Plus, the lime in hempcrete has a high pH level, which makes it naturally:

• Pest-proof: Termites and rodents hate it.
• Fire-resistant: It won't catch fire, and it doesn't release toxic smoke if exposed to high heat.
• Rot-resistant: It’s designed to last for centuries.

5. Cost Differences: Upfront vs. Long-Term

Let’s talk numbers. In 2026, the upfront cost of hempcrete is still generally higher than traditional concrete or standard "stick-frame" construction with fiberglass insulation.

Why?

• Supply Chain: While growing, hemp is becoming more common, the processing facilities (decortication plants) are still catching up to the massive cement industry.
• Labor: It requires a bit more specialized knowledge to install correctly.

However, when you look at the Life Cycle Cost, the gap narrows:

1. Fewer Layers: A hempcrete wall replaces the insulation, the vapor barrier, and the drywall. You’re paying for one thick, high-performing material instead of five different products.
2. Energy Savings: Because of the superior R-value and thermal mass, your monthly energy bills are significantly lower.
3. Durability: You won't be dealing with mold remediation or rot issues 20 years down the line.

Which is Right for Your Project?

At Farris General Contracting, we don't think it has to be "either/or." The best custom home builds often use both.

Choose Traditional Concrete for:

• Your foundation and footings.
• Your garage floor and driveway.
• High-strength structural beams.

Choose Hempcrete for:

• Exterior walls of your home or addition.
• Internal partition walls where you want soundproofing and temperature control.
• Eco-conscious projects where "living healthy" is a priority.

Ready to Explore Sustainable Building?

Starting a new project can feel overwhelming, but it doesn't have to be! Whether you’re interested in the latest sustainable tech like hempcrete or you want a rock-solid traditional build, our team is here to guide you through every step.

Don’t forget to check out our Our Work page to see some of the recent projects we’ve completed across the region. And stay tuned for Part 3 of our series, where we’ll show you exactly how a hempcrete wall is built from start to finish!

Want to chat about your next project? Contact us here or give us a call. We’d love to help you build something that lasts.

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