What is Rammed Earth
Rammed earth is a timeless building technique that combines natural beauty with strength, sustainability, and thermal performance. Made by compacting a mix of gravel, sand, silt, clay, and a stabilizing agent—typically cement—into formwork, rammed earth creates solid, durable walls with a distinctive, earthy aesthetic.
At Rammed Designs, we specialize in stabilized rammed earth construction, combining traditional knowledge with modern engineering to deliver walls that are not only structurally sound but also visually striking. Rammed earth’s natural thermal mass helps regulate indoor temperatures, reducing the need for artificial heating and cooling—making it a smart, eco-conscious choice for Australian homes and buildings.
With its low embodied energy, longevity, and fire resistance, rammed earth is ideal for sustainable architecture in Northern New South Wales and South East Queensland. Every wall we build is unique, reflecting the tones and textures of the local landscape.
Key Benefits:
• Thermal Comfort: The high thermal mass of rammed earth walls helps regulate indoor temperatures, keeping your home cooler in summer and warmer in winter, leading to reduced energy bills.
• Fire Resistance: Rammed earth walls have achieved a 4-hour fire resistance rating, making them ideal for bushfire-prone areas.
• Acoustic Performance: With a sound transmission class rating of 57, these walls provide excellent noise insulation.
• Aesthetic Appeal: Each wall is unique, showcasing natural textures and colors that blend seamlessly with the environment.
Choosing rammed earth means investing in a home that’s durable, low-maintenance, and environmentally friendly.
🛠️ Technical Specifications: Stabilized Rammed Earth
For architects, engineers, and builders, stabilized rammed earth (SRE) offers a robust and sustainable construction solution.
Material Composition:
• Soil Mix: A blend of sand (60–70%), gravel, silt, and clay (20–30%), stabilized with 5–10% cement.
• Density: Approximately 2000 kg/m³, contributing to its structural integrity and thermal properties.
Structural Properties:
• Compressive Strength: Typically ranges from 2 MPa to over 8 MPa, exceeding the minimum requirement of 2 MPa as per building codes.
• Wall Thickness:
• Standard: 300mm for load-bearing walls.
• Insulated Walls: Start at 400mm with a 50mm insulation insert, achieving R-values up to 2.48.
Performance Characteristics:
• Fire Rating: 4-hour resistance, suitable for high fire risk zones.
• Acoustic Rating: Sound transmission class of 57, providing effective noise reduction.
• Erosion Resistance: Accelerated erosion tests show 0–0mm/min, indicating high durability.
Construction Process:
1. Formwork Setup: Custom-designed formwork is erected based on project specifications.
2. Mix Preparation: The soil mix is prepared with precise proportions of aggregates and stabilizer.
3. Layering and Compaction: The mix is placed in layers and compacted using pneumatic or electric rammers to achieve desired density.
4. Curing: Walls are allowed to cure, developing strength and stability over time.
Our construction methods align with the Australian Earth Building Handbook HB195 and meet the requirements of AS 3959 – 2009 for construction in bushfire-prone areas.
By integrating these specifications, we ensure that our rammed earth constructions are not only aesthetically pleasing but also meet the highest standards of safety and performance.
If you need further customization or additional information, feel free to ask!
FAQs
Facts & Questions About Rammed Earth
A smart, natural building material—timeless in look, modern in performance.
Click a question below to learn more.
1. Design & Aesthetic FAQs
What is Stabilized Rammed Earth (SRE)?
Stabilized Rammed Earth is a method where layers of earth—sand, gravel, clay, and a small amount of cement—are compressed in place to form strong, thermal, and striking walls. It’s where ancient technique meets modern performance.
Can I have curved rammed earth walls?
Yes! Curved walls are possible and often even stronger structurally. Custom curved formwork is used, which requires more planning—but the results are unique and visually stunning.
What finishes are available?
Walls are often left raw to showcase their natural texture and layered tones. However, they can be sealed, burnished, or tinted with oxides for a customised finish. Each wall is unique—no two are the same.
Do I need a specialist architect or builder?
Not necessarily. We’re happy to work with your architect or builder, offering advice during the design and build phases. Rammed earth thrives with early planning, and we’re here to make the process smooth.
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2. Performance & Environmental FAQs
Are rammed earth walls energy-efficient?
Yes. Their high thermal mass absorbs heat during the day and releases it at night, keeping internal temperatures stable. When insulated, rammed earth walls can reach R-values of 2.4 or more—perfect for energy-efficient design.
Are rammed earth walls fire-safe?
Absolutely. Our walls are rated for up to 4 hours of fire resistance, exceeding requirements for homes in bushfire-prone areas (complying with AS 3959 – 2009).
Are they termite-resistant?
Yes. Rammed earth contains no organic material for termites to eat, and its dense structure offers no entry points—meeting termite-resistance standards in the Australian Building Code.
Do the walls need sealing or maintenance?
Interior walls typically don’t require sealing. For external walls, we apply breathable water-repellent sealers to protect against rain. With good design, maintenance is minimal—just occasional cleaning or resealing every 15+ years.
What’s the lifespan of a rammed earth wall?
Well-built rammed earth walls can last well over 100 years. Globally, many historical examples have lasted for centuries. It’s a legacy material with modern benefits.
Is rammed earth sustainable?
Yes. Rammed earth uses local, natural materials with low embodied energy compared to concrete or brick. It performs well thermally, reducing your energy use over time.
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3. Construction & Practical FAQs
How thick are rammed earth walls?
• 200mm – Internal or non-load-bearing
• 300mm – Standard load-bearing wall
• 400mm+ – Allows for insulation layers (e.g. 50mm PIR inserts) to increase R-values and meet energy targets
Can electrical and plumbing services go through rammed earth walls?
Yes. All conduits and pipes are planned in advance and integrated during the wall-building process. There’s no need for chasing or cutting after construction.
Are rammed earth walls waterproof?
While not inherently waterproof, external walls are sealed with breathable products that allow vapor to escape while protecting against water ingress. Correct roof overhangs and detailing are also essential.
Is rammed earth more expensive than traditional construction?
Upfront costs may be higher than brick or timber, but the benefits—thermal efficiency, low maintenance, unique aesthetic, and long life—often result in lower lifetime costs and higher long-term value.
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Still Have Questions?
We’d love to talk. Whether you’re just exploring ideas or ready to build, we’re here to help.
[Contact us] or [Explore our Projects] to see rammed earth in action.