UD-03 · 03 Urban Design
Rammed earth infill
Walls made from the site's own subsoil, compacted in a formwork, so a room can be added without a truck of fired brick.
Origin
Pisé, hangtu, and contemporary stabilized earth
Materials
- Subsoil tested for a workable sand–silt–clay mix
- A simple timber formwork and a rammer
- A wide roof overhang and a stone or rubble plinth
- Stabilizer only if the soil and climate demand it
Method
- 01
Test the soil. Too much clay and the wall cracks; too much sand and it will not bind. A jar test and a small sample wall save a season.
- 02
Raise the wall on a plinth above splash height. Earth fails from the wet foot, not from the sky, if the roof is honest.
- 03
Ram in lifts. Each layer is a day's work you can see. Do not pour earth as if it were concrete.
- 04
Cure out of hard rain. Then cap with a roof that throws water a full pace from the wall.
- 05
Finish with a breathable lime or clay plaster. A plastic paint will trap moisture and undo the wall.
What this makes possible
- Mass that holds night cool and day heat
- A wall whose material bill is mostly labor and local ground
- A skill that can be taught on the job, in public
This is a field record, not a permit. Adapt to local law, climate and skill. If you have run this method, send what you learned.