Why Plastic-Wrapped Bales Don’t Belong in a Strawbale Home
What About using Plastic-Wrapped Bales in a Strawbale Home?
Every so often, someone asks about the idea of using plastic-encased straw bales to build a strawbale home. On the surface, it might sound convenient—less mess, no need for vapor barriers, maybe even easier stacking.
But after years of building, designing, and teaching, we can confidently say: This is a bad idea.
Let’s walk you through why.
💨 Strawbale Homes Must Breathe
The beauty of a strawbale wall system is its ability to manage moisture naturally. We’re not talking about rain or standing water—we’re talking about water vapor from everyday life:
A long shower without the fan on
Boiling pasta
Breathing, cooking, even houseplants
That moisture doesn’t just disappear—it moves through your wall system, especially in a pressurized house (which most homes are).
If the bales are wrapped in plastic, that moisture gets trapped. It tries to pass through and instead gets stuck, collecting inside the wall with nowhere to go.
The result? A plastic-wrapped box of composted mush. Literally.
Plastic Disrupts Plaster Bonding
Another key feature of a properly done straw bale wall system is the bond between plaster and straw. This bond:
Adds structural integrity
Prevents air gaps
Creates a seamless, durable finish
If your bales are wrapped in plastic, the plaster can’t grip the straw—it’s like trying to stucco over a shower curtain. You’ll lose a key part of what makes strawbale walls strong and long-lasting.
But What About the Perks?
Let’s break down a few of the common arguments for plastic bales—and why they fall short.
❓ “No need for vapor barrier!”
True, but natural bale walls don't need one anyway. Their vapor permeability is part of what makes them work.
❓ “Easier to stack!”
Maybe—but are you really saving time if it risks mold and ultimately failure?
❓ “I can mortar them together!”
Why would you? The best bale systems don’t require mortar, and plastic makes plastering worse, not better.
🌿 Keep It Natural, Keep It Simple
The risks of wrapping bales in plastic far outweigh any perceived convenience. You lose:
Vapor permeability
Structural bonding
Long-term durability
And you gain:
Moisture retention
Potential mold
A high-risk experiment with your home
Stick with unwrapped bales and breathable plasters. That’s what we teach, that’s what works—and that’s what will keep your strawbale home standing strong for decades.
🛠️ Want to Build a Healthy, Long-Lasting Strawbale Home?
Learn how to avoid costly mistakes before they happen.
👷♀️ Join us at a hands-on workshop to get the skills you need.
💬 Can’t wait? Book a consult and get expert advice to keep your project moving forward with confidence.
Updated: September 15, 2025
