Most walls are straight, but not all buildings need to be. Curved interlocking soil blocks are pressed to form arcs, which makes it possible to build round houses and circular water tanks with the same simple technique used for straight walls. Our Curved Interlocking Soil Block Press is designed for exactly this.

Why build round?

• Efficient shape: a circle encloses a given floor area with less wall length than a square.
• Even load paths: a closed circular wall spreads loads around the ring.
• Appearance: rounded buildings stand out and are popular for lodges, offices, kitchens and community buildings.

Round houses and rooms

For houses, the main design questions are the roof and the openings. A conical or domed roof on a round plan needs to be designed carefully so loads are carried properly down into the walls and a ring beam. Door and window openings need lintels, and you should plan reinforcement around them just as you would in a straight wall.

Water tanks

A water tank adds one major factor: water pressure on the wall. A tank is not an ordinary wall and should be designed by an engineer. Points to discuss include:

• A reinforced concrete base slab that is properly designed and waterproofed.
• Horizontal and vertical reinforcement in the wall to resist the outward pressure of water.
• A suitable internal waterproof lining or render.
• Overflow, outlet and cleaning arrangements, and a cover to keep out dirt and mosquitoes.

Do not improvise tank design from general advice. A failure can cause damage and injury.

Practical building tips

• Mark out the circle carefully from a fixed centre point with a string or rod.
• Check each course for level and for radius as you build.
• Follow the same curing practice as for straight blocks: see curing stabilised soil blocks.

Learn more

The general wall-building sequence is covered in building walls with interlocking blocks. To see completed work from our clients, visit our projects page.

• curved blocks
• round houses
• water tanks