Cob House Build START to FINISH in 10 Minutes

this video is a time lapse of a Cobb Cottage Workshop that took place over 5 weeks in the North Carolina Mountains we built this Mud House using local natural materials including clay sand straw and roundwood Timbers using the footage from this Workshop I was able to create a 7even episode in-depth tutorial series on how to build a cob house which can be found on our YouTube channel playlist section in this video we'll be briefly covering each step of the building process which includes building the foundation and Earth and floor making cob sculpting cob walls making

and applying clay plaster and building a reciprocal living roof before making Cobb we first had to build our foundation and when you build a house with Earth and materials it's important to build strong foundations with adequate drainage and strong roofs with large overhangs to protect the walls we start our foundation by digging a drainage trench that slopes slightly downhill and we test our trench by pouring water in at the high side once we confirm proper drainage we can then lay the Landscaping cloth and fill the trench with compacted gravel next we can stack our stone

foundation which elevates the cob walls off the ground to keep them dry and also structurally supports the weight of our wall system with the foundation complete we were now ready to begin installing our Earth and floor we start by adding a compacted layer of gravel for drainage purposes and once this is compacted and leveled we can then lay our insulation layer using scrap pieces of cardboard we apply a layer of clay slip to the cardboard and then we can begin pouring and leveling our base layer for our Earth and floor for the base layer we

use a mixture of clay sand gravel and straw and we pour the floor to a depth of about 4 in we continue on with this process integrating the mix into itself and leveling it out until the base layer is complete we were now ready to make our first batch of cob which is created using a mixture of clay sand straw and water We Begin by dry mixing our clay and sand and then adding water before stomping the mix out with our feet this method of cob mixing is referred to as the tarp method and it's

the only method we use to build this entire Cottage as you continue adding water to the clay and sand stomping it out and rolling it with the tarp the mix becomes homogeneous and begins to form this burrito shape once you arrive at the proper consistency you can then add straw which helps to provide tensile strength in the wall system you continue mixing and stomping until the cob is entirely homogeneous and the straw is Thoroughly integrated throughout the mix lastly you shape the cob loaves to make transporting and building with cob easier we apply clay slip

to the top of the foundation and then we begin building our Walls by laying cob loaves down and sewing through the mix with our hands to create a monolithic Mass you first want to get rid of any seams in the wall and then work on getting to your desired shape to transport the cob to to the building site we make a line and toss the cob to one another we then work as a team to continue integrating and shaping the mix again with the goal of creating a singular monolithic Mass with no seams and we

use a tool called a cober's thumb to sew through the mix and integrate the layers as we continue building up more layers of Cobb we integrate into the layer below by working through the mix with our hands once there is a significant layer of Cobb on the wall we can go back and use levels and saws to trim the cob wall into our desired shape once we install our door and window frames the speed that we gain height in our cob walls improves drastically we continue on making more cob building up our walls integrating the

layers and then going back to trim and level the edge of the [Music] wall we shape the cob around our door and window frames and as we work towards the top of the cob wall we embed roof tees which will allow for a structural tie from from the roof into the wall system with our cob walls complete we were now ready to transition to the sculpting and Plastering portion of the build using a similar mixture of clay sand and straw we add sculptural details to the cob walls which really begin to bring the building to

a whole new life we start by moistening the cob wall so that the sculptures can bond to the existing cob and we build out designs shapes animals niches and and shelves with the sculptural details we continue shaping the cob around the windows carving out the niches and shaping the fine details around bottle bricks lastly we intentionally poke holes in all of the sculptures to make it easier for the plaster to bond during the plastering process using various mixes of clay soil coarse sand fine sand and manure we create and apply test batches of plaster to

the wall to see how they would perform given the results we chose to use these ratios for the interior and the exterior plaster we then broke off into teams to create several batches of plaster before adding all the separate mixes into one bin and giving it a Final Mix to ensure that the mix was homogeneous to apply the clay plaster we again moisten the wall with water to create a better bond between the cob wall and the plaster and then we use Hawks and trowels to spread and shape the plaster on the wall we use

a collection of rigid and flexible trowels to achieve various finishes and we also use yogurt lids and spoons for more Precision on areas with finer details we start from the top of the wall and we work our way towards the bottom continuing to refine the details and the shapes as we work our way down to achieve a fine finish we go back and burnish areas that need it to smooth everything out with the exterior Plastering almost complete we prepare to start apply applying the interior plaster for the interior plaster we repeat the same process of

moistening the wall and applying and shaping the clay plaster on the interior we use the plaster to smooth out the finishes on our sculptures we Define the shapes around the bottle bricks and we plaster flush to all of our door and window frames during this stage of the build we install tile and marble mosaics and also finalize the sh shapes around our niches and shelves after adding our finishing touches to the interior plaster we prepare to start building our reciprocal living roof earlier in the build we installed a bond beam that attaches to the roof

te's that are embedded in the wall this system provides a structural tie from the roof into the wall system and with the bond beam and Plastering complete we were ready to begin installing our Rafters a reciprocal roof is a beautiful and functional roof system in which all of the rafters support one another requiring no Center support to hold the load for the reciprocal roof we place the first rafter on the Charlie stick which acts as a temporary support to hold the weight of the roof until the final rafter is installed we work our way around

attaching the rafters with threaded rods and bolts and once we get to the final rafter we lift slightly on the rest of the rafters and Slide the final rafter into Place once all the primary Rafters are securely installed we can then remove Our Charlie stick we repeat a similar process to install the secondary Rafters which add structural support for our sheathing boards and then we begin cutting and installing shims to level out the planes of our roof once all of the shim boards are installed our roof is now ready to receive sheathing we attach our

sheathing boards to the shims and rafters and then we come back with a chalk line to give them all a clean cut once the sheathing boards are all complete we then install our insulation layer using scrap pieces of carpet followed by our waterproof membrane to build up the layers of our living roof we start with a base layer of sand followed by a layer of straw and then lastly a layer of local clay soil to finish the roof we build drainage down spouts attach fascia boards and install a skylight in the center of the roof

we now only had a few things left to do to finish this build we made a few more batches of cob to finish closing the gap between the top of the cob ball and the roof and then we made and applied our last batches of clay plaster to prepare the install for the final layer of the finished earn floor we dampen the floor and then we create our mixture using clay sand and manure we pour the Earth and floor mix onto the ground and then we use screed boards and trowels to level everything up we

continue on going section by section until the Earth and floor is complete for the final step of the build we install the front door and then the Cobb Cottage is complete if you'd like to learn more about how to build a Cobb house be sure to check out our full tutorial Series where I go much more in depth into each stage of the building process also follow us on Instagram at natural buildings to keep up with our latest projects