Cob bricks and new wall plates!

July Camp Cob 2011This July’s camp cob at Le Petit Givais in France was absolutely cob brick-tastic! A massive thanks to all those feet and hands that helped stamp, roll and squelch to make an LPG record of over 200 bricks made in one visit!

These bricks were made using a 1:1:1 mix of sand, straw and clay with 1/4 bucket of water depending of wetness of sand and how hot it was. We have quite silty clay on our site so we do not mix too much sand in as it would make the bricks too friable, (which is when the surface is really grainy and sandy to touch with lots of surface coming away when you rub it). Once you’ve mixed the cob, by foot in our case on tarps, the cob mix can then be firmly packed into the brick forms which need a good hosing down with water first otherwise you will never get your bricks out or off the board!

Once out of the forms they can be left to dry in a shady spot (in the barn in our case) with plenty of ventilation. The bricks are then turned every day and eventually stacked ready for use. We leave our bricks for a minimum of three weeks to three months depending on weather and ventilation. Our new bricks won’t get used until next year now so will be totally dried out by the time we come to put them in a wall. With restoration the reason you can’t use wet bricks is that the wall you are putting them into is dry, so if you put in wet bricks they will dry in the wall, which will mean any shrinkage or cracking will occur in the wall. So in order to have the right size brick that you know isn’t going to break you need to wait for them to dry outside the wall first. No doubt that’s all as clear as mud?!

We also have a new wall plate coming to replace the one we currently have which is rotten in the middle. The photo you can see top left, shows how the ceiling joists have been propped, then holes cut through the cob under the main ‘A frame’ timbers and blocks and wedges hammered in and then with these timbers supported the rest of the cob has now been taken out. A new wall plate can then be found and cut to fit the existing timber frame roof, the old wall plate taken out, the new one put in and then we can brick up the cob underneath with some of our fantastically made new cob bricks.

This year will also see the new drainage and sceptic tank going in, the holes for the sceptic tank and new filter bed will also generate lots of new clay for us, saving us loads of time, as many a day has been lost ‘in the pit’ digging up clay. Although it has to be said, that digging in the now enormous pit is strangely a very popular activity!

This year we also took off the last remaining bits of concrete in the flint plinth with one small stretch left now to rebuild and re-point, phew! It’s quite a healing process smashing concrete off of beautiful buildings, I highly recommend it! We also filled in the last remaining cob holes in the gable end wall leaving it ready to be Lime rendered next year.

Next year at LPG will see some new drainage, the flint plinth finished, the gable end wall rendered, the brick wall re built and tied back to the cob and the last remaining concrete window removed and all the new timber doors and windows fitted, quite an exciting year next year, can’t wait!

Thanks again from the Cavey team to all those that came out, made bricks, fixed walls, smashed concrete and ate their weight in cheese! You are all stars!