Mud@Wood center i.e. Feile Butler, architect and Colin Ritchie, carpenter., organized in Grange Br, Skreen, Ireland 9 day intensive workshop for ’rammed earth’ or ’cop-building’. Basically it was about one style of using sub-soil( clay), sand, gravels, straw, water and moulds i.e frameworks to construct walls and houses. The particular thickness varies usually between 30-80 cm. Their house below has outer walls of about 60 cm. The north and cold-wind sides are straw-bale construction.
As result this workshop will contribute to workshops of kind organized in Finland at Luvattula and other places around with similar perspectives. There is a remarkble potentia for utilizing the subsoil all around construction sites i particular. One of the focus will be in the design of practical frameworks using local resources.
One begins the cob-process with mixing subsoil, sand ( between 1:3 -1:5) and water. After analysis of right stiffiness , straw is added. Sometimes straw is chopped shorter pieces, below with trimmer and big bag. In the workshop mixing of basic ingredients was introduced by doing it with feet over a kind of blanket or cover.
But in practice doing the mix with digger is lot of help. Mixing is usually best done inside a grave on place where the subsoil is met, usually on the construction site itself.
Colin (host) is very keen on illustrating in a sandbox the real stuff 😉
There is a need for framework in order to ram the mixture to wall. Below curved moulds were made by cluing and screwing 3 flexible plywood plates together in jig at a time.
Frameworks are joined to rise and ram the wall one layer at a time. Cob is added gradually and ”dance-rammed” to be as tight as possible. One can use background music 😉 Wooden big hammers are also used for corners and edges. ”Rising Together” has now double meaning. We raise walls and we educate ourselves to rise or co-evolve with each other. Communal life ina deeper oe ”higher” way.
To star with old surface is painted with a kind of clay fluid.
Connecting framework pieces together, simple and fast.
Interesting moment there is to see the traces of work done when moulds are removed below. You open the shreds covered by plastic tubes traversing the wall.
Some fixing can still be made to banks, steps, etc. with heavy wooden hammers. Notice the hole like spots done my wooden stick to the surface for joining next layer firmly.
Again clay for cluing. Notice the deeper spots for binding old laye of cob to a fresh one. Below a place for window is structured. The principle of fixing opposite frameworks together with plastic tubes and shreds is clearly seen.
The result below is again rewarding.
Mixing sieved subsoil, sand and cow manure, 3:1:0,5 produces the first blastering layer to plain plumps and graves. Applied below to and old wall as an exercise. Bore-sulfate(borax) was added in order to prevent molding.
Below finishing plaster , china clay, sand (2:1) , flour paste 5% and fine-chopped straw , was spread as demo-purpose to the new wall directly. Bore-sulfate again ..
Some experiments were done adding decoration to older cob-wall. Hidden nails keep things together. The trianguloid was done by author himself ;))
Rewind backto the first-day’s introductory workshop to meet the bigger audience. Collective decoration process in the air…Feile ( hostess) is looking forward to see the results 😉
The theory of earth properties which makes it approprieate as buildning material. This below is not dinner-table 😉
Water is crucial component in structures. capillary effect brings the sand tower to rise higher and fall in an ongoing loop.
When fine sand is tigthly rammed into a volume of drinking glass it can support even 5 kg! I was told to break the rekord of ramming ever made when asked to fill and ram the cup :))
The name of the course was indeed Mud& Wood. Below in door some characteristics of woodworks that are distinct to practices of the place. The whole house was built using only abandoned wood and the style in general was about natural surfaces.
Really a chair.
Happy woodworking and earth-ramming ! The End …
From my point of view this workshow introduced a potential to design buildings with the subsoil available aroud. Basically finnish climate resembles a lot the irish one with more concerns related to frozen earth at wintertime. main focus seems to be in constructing interior walls with cob. That approach brings all the benefits related to rammed earth, i.e interior air quality, economics and temperature balancing. And not to forget the community-oriented and education-potential aspects when doing the construction work in a group.
That workshop enforced my personal view of a hybrid approach in designing an ecologically sound building. Be free and open to a diverse set of proper materials and design. Every building in particular has at least four directions, there are four seasons and during a day different conditions and needs among people and nature.
Treat the sections and directions of your home according to their own nature like yours !