this is the diagram of all the main components of taula amiga farm table.
after the wood structure there are 8 layers:
layer 1 – 1000x4000mm – fabric, any soft material, old cotton sheets or old blankets are perfect materials. this layer is for protecting the thin film of PP plastic (layer2) from touching the non pollished wooden floor.
layer 2 – 1240x4240mm – PP plastic fim 0.2 > 1mm. this should be a food grade plastic. this layer is the main drainage membrane. if punched or not well sealed on the draining holes (10 per table) the water will damage the wood structure of the table.
layer 3 – 150L – drainage material can be small rocks, sand, expanded clay or any inert material. this layer can also be used has a water reservoir for capillarity systems.
layer 4 – 1000x4000mm – TNT fabric, used to prevent the roots from entering the layer 3
layer 5 – 1000x4000mm – wood net. this layer is for prevent any damage on the sub layers like working on the soil with big tools so when someone reaches this layer knows that’s the end of the soil :) the wood has also a secondary function. it will rot slowly producing heat and a home for micro life.
layer 6 – 10000L of coco fiber. coco fiber is an excellent soil structure, it retains moisture and nutrients, the roots have no problem on diving in it and is very light.
layer 7 – 4000L of humus. this is a lot of humus and this is just for one table. we already started the composting systems but we need to go fast or find local sources of good humus.
layer 8 – 1000x4000mm – wood net. this layer is to divide the table by family of vegetables, reinforce the side structure and hold the watering system in position.