Better Than Rebar: Straw Bale House Building
Why We’ve Moved Away from Rebar in Straw Bale House Building
When it comes to straw bale house building, many people still assume that rebar is a necessary component for structural integrity in infill bale wall systems. And, rightly so, as for years, rebar was considered standard, and in some building codes, it may still listed as a requirement.
But based on years of hands-on experience, ongoing research, and real-world results, we’ve found that rebar is no longer necessary—and may even be counterproductive—in many modern straw bale wall systems.
No disrespect to the older best practices is intended! Crafts, techniques, and best practices advance over time to deliver stronger walls, safer straw homes, and easier builds.
🔍 What’s the Problem with Rebar in Straw Bale House Walls?
1. Risk of Moisture Intrusion
Cold steel inside a straw bale wall creates the perfect target for moisture-laden air to condense on. While high-quality plaster does an excellent job of moisture defense, tiny air leaks can still happen, and over time, condensation can lead to hidden rot.
Beyond air infiltration leaks, the plaster itself is permeable. This is a good thing as it allows moisture to move out of the bale walls!
“Nature is persistent, and air leaks can still exist in even the best-built bale home.”
2. It’s Difficult to Work With
Installing bales over rebar can be a literal pain in the neck.
You have to lift and drop a 45-pound bale 30 inches in the air.
You must align and slide it down over steel rods—often several times per wall.
Driving rebar into the bales as you go is time-consuming, frustrating, and unnecessary.
3. It Conflicts with Moisture Isolation Best Practices
Most modern straw bale house building systems include a moisture break between the foundation and the bales. Rebar, when anchored to the foundation, creates a direct path for moisture to travel up into the wall system—defeating the purpose of that barrier.
4. Rebar Doesn’t Hold Bales Securely
Contrary to common belief, rebar does not anchor bales effectively. It allows vertical movement and lacks gripping power. A more effective solution?
✅ 20-penny nails driven into the toe-ups at 4" intervals, staggered from side to side. These act like teeth, grabbing and holding the bales in place far better than rebar ever could.
✅ A Better Way to Build: Mesh & Nail System
Our preference is to use a bale wall system that is:
Easier to install
Stronger under compression and load
Safer in terms of moisture and structural performance
Here’s how it works:
Toe-up Preparation: Drive 20-penny nails into the wood toe-ups on both sides, staggered to maximize grip.
Mesh Attachment: Attach welded wire mesh to the framing.
Sew Through: Use wire or twine to sew through the wall, tightening the mesh across the bales and securing the system.
The result? A tight, stable wall system that is a joy to plaster and built to last by providing a very stable substrate for the plaster.
Want to see it for yourself asap? Visit our On-Demand Learning Center and look for the How-To Straw Bale Building Series.
🛠 Building the Future
The use of rebar in straw bale house building came from well-meaning, practical experimentation—and it played a key role in helping the technology of straw bale construction evolve. But like any evolving craft, we learn, we improve, and we adapt.
At Strawbale.com, we’re committed to sharing the best available practices so builders—DIY or professional—can create long-lasting, energy efficient, and safe straw bale homes with the most efficient processes possible.
🙌 Want to Learn More About Straw Bale House Building?
Join us for a hands-on learning experience so you can build your strawbale dream home with confidence.
Updated: April 11, 2025
