Our 100mm cob blocks are manufactured from 100% natural and sustainable materials that are sourced locally. So, what does one of our cob blocks consist of? Well, the most important ingredient is clay. Sub-soils that contain clay (particularly here in Cornwall) are common-place and this remains the principal reason why there is an abundance of cob-built walls in the South-west. Clay (unfired) alone is proven not to be so successful as a building medium, therefore sub-soils must also include gravels, aggregates and sands. And so, once again, we are blessed here in Cornwall for the natural geology houses all of these elements. Straw is an additive at the mixing stage and this assists with binding the mixture together to make it more user-friendly and during the drying process reduces the risk of excessive shrinkage.
At pre-manufacture a cob block weighs 18.5kg. This is the quantity of material that is introduced into our machine. By the time it has dried it will weigh16kg.