Plinth

The oak frame needs to be separated from the ground to protect it from damp. The usual way of doing this is with a masonry plinth.

We chose reclaimed Suffolk red bricks from a local reclaim yard for our plinth.


The brick plinth starts below ground on top of the limecrete footing, and rises to at least 1 foot above ground level. The bricks are bedded in a mortar made from sharp sand and natural hydraulic lime, no cement. As with the limecrete, the lime mortar translates to an 80% reduction in carbon emissions.

Traditional lime mortar is also much more flexible than cement mortar. It can accomodate the tiny movements in the building over time without cracking, making it ultimately more durable than cement. Unlike cement mortar, lime mortar is breathable. It encourages moisture to evaporate away from the plinth, rather than being retained in the wall.



The lime mortar will weather naturally over time. It gives a soft, attractive result which complements the tradition Suffolk red bricks.

Foundations

The site for the building is on heavy clay. We removed the clay and put it aside to use later for making the daub.


We filled the lower part of the foundations with drainage gravel with a drainage pipe bedded into it. The drainage pipe leads to a deep soakaway below the clay layer. These "self-draining" foundations encourage moisture to move away from under the foundations and not rise up the wall.


On top of the drainage layer, we layed a limecrete footing. Limecrete works like concrete, but instead of cement, natural hydraulic lime is used. Lime production releases 80% less CO2 than cement production, so reduces the environmental impact of the building. Limecrete is also more flexible and breathable than cement, so is more appropriate for a building which uses natural materials.