Production and Quality
Part of what distinguishes SIREWALL from what we refer to as 'traditional rammed earth' has to do with what materials we build with, and part has to do with how we build. In both cases, our rigorous production quality protocol is maintained by a certified SIREWALL project manager who personally directs all work on site, without exception.
Soil Sourcing, Analysis, and Testing
Soil is a word often associated with topsoil, the living and lifegiving organic loam so essential to our survival. But when we use the word 'soil', we are referring to something entirely different - we are talking about totally inorganic soil, which consists exclusively of particles of broken up rock. The last time you visited a pristine beach, part of what you were experiencing was inorganic soil.
A wall can be no better than the material it is made with. For this reason, we typically import material onto our sites rather than use on-site soils. Prior to construction, we visit local gravel pits to collect samples of material taken below the C-Horizon, just above the bedrock level, where consistent quality material totally free of organic matter can be economically harvested in abundance.
Because we use material too fine for road construction contractors (who are the primary customers of gravel pits), we are buying waste material. There are usually gravel pits near roads, so we have never sourced soil further than thirty minutes from a project. The cost and the carbon footprint embedded in this choice of material is extremely limited in comparison to other building materials.
Soil samples collected from the potential soil sources for a project are then evaluated using computer analysis to predict optimum potential soil mixes, then sample material cylinders are rammed and sent to independent labs for testing. This means that actual hard engineering data specific to the project in question will be available for structural engineers to work with during design.
Color Choice and Management
Once the soils to be used for the project are confirmed, color samples are built to give the owner and designer a range of choices reflecting their conceptual color preferences.
These samples will accurately show the colors that would be produced, but not reveal their full character in a wall. The next step is to identify which options are 
finalists and use them to build a larger test wall.
In the images below, the designer was interested in four possible colors. Color 'A' was selected as the primary color, with accents of 'C' and 'D' woven in. The lower right image shows the results in the final walls.
Test walls often present great opportunities to create rammed earth elements in the landscape, such as entry signs, gateways, or bollards. To the right, architect Tom Kundig is working with a test wall built for a project in Hawaii. This wall used varying levels of iron oxides that created a red clay character reflecting the local soils.
Regional character is often a good starting point for making color choices. In the image below, the goal was to create a golden hue to play off limestone prevalent on the site.
Local Material and Labor Procurement
When we mobilize onto the construction site, we will use primarily local sources to procure the balance of the materials and equipment that will be required, and we will hire local laborers. The on-site SIREWALL Project Manager will manage a crew of up to four workers to expedite labor-intensive formwork assembly and ramming. For larger projects or projects on a fast track schedule, additional SIREWALL Project Managers will be located on-site to maintain a one-to-four ratio within five man crews.
Forming, Mixing, and Ramming
SIREWALL formwork differs from concrete formwork in part because it is entirely externally supported. And in contrast to traditional rammed earth, SIREWALL presents a visually minimal and refined finished surface to which the most subtle features of the formwork permanently telegraph.
Formwork typically represents one of the most time consuming and technically demanding components of building SIREWALL.
Different methods of production will be used for projects of different scales.
Stripping, Curing, and Coatings
Once the ramming is complete, curing protocols for the walls will be determined by a variety of factors, including the weather on the site. Rammed earth cures at a more steady pace than concrete, and for a much longer period of time.
The much anticipated moment when the formwork is taken down and the walls are revealed is a thrill that never seems to lose its impact.
There are no coatings to apply, now or ever. Proprietary admixtures contained in the wall make them unnecessary. (The only exception could be an anti-graffiti product.)
At this point, in contrast to most other types of construction, the walls are complete, and other trades can proceed with the balance of construction.
Research and Development
SIREWALL was born out of a commitment to radically improve existing technologies, and remains committed to ongoing research and development to continually improve the product it produces and the processes it employs. The Canadian federal government has supported SIREWALL with extensive funding for qualified research in labs and on project sites into a wide range of topics, including:
- Soil
- Straight formwork
- Curved formwork
- Formwork facing
- Insulation
- Tampers
- Admixtures for strength
- Anti-efflorescense admixtures
- Hydrophobic admixtures
- Rising damp
- Reinforcing
- Ambient microwave pollution
SIREWALL prioritizes its research efforts emphasizing health, energy efficiency, environmental appropriateness, aesthetics, and durability.