The Cave Co-operative sustainable architects

This July Camp Cob was all about bricks!

We made as many bricks as our little feet could muster! We dug, we dryed, we sieved, we measured, we mixed, we treaded, jumped and danced, we rolled and rolled, we jumped, danced, stamped, conga-ed and rolled some more, all the way to the perfect mix. At this point, normally some merciful soul has produced some tea and biccies!

We then give the brick forms and board a good hose down (so the Cob doesn’t stick) and then take our fab’ mix, pack it well down into the molds, being careful to pack into corners and eliminate any air bubbles. Give it a good tamping down, whether by standing on it or smacking it with lumps of wood, or anything else that comes to hand. Then lift the forms (easier said than done!) and shake carefully, from not too high until all your bricks have dropped out, magic!

Oh, and then start all over again!

The bricks are then left to dry in a shady, rain proof spot, turned every other day or so and in a months time you should have some fully dried out bricks ready for any cob repair jobs that your walls may have to offer.

As with our last months mission to Camp Cob, this month we are progressing the Lime re-pointing of the Flint plinth wall. You can see from the first image that in some cases there are some quite large holes to repair!

We had lots of volunteers helping with this task, so thanks to all those who gave a helping hand, you know who you are!

Re-pointing such large holes takes an extremely long time and much patience! It is not the type of job for you if you like doing things quickly. The lime can only be applied in layers about 10mm thick and takes a day or two to be what’s called ‘green hard’, which is where you can just make a small imprint on the lime with your thumb nail, before you can apply another layer, so it is quite slow going, but a great meditation!

In the final picture you can see part of the finished wall, which once the last layer has been applied, smoothed and angled to allow for rain run-off (be careful not to leave any areas where rain can collect!) the mortar is left for a day to carbonate and harden a bit before giving it all a good scrub with a wire brush to clear any mortar from the stones and after a light spray with the hose, Hey-presto! One fantastic, re-pointed flint wall!

We got our ready mixed lime mortar from the lovely people at Chalkdown Lime and our tools from the equally lovely people at Mike Wyes, you can find both their websites below and they are all very knowledgeable on all things lime!

www.chalkdownlime.co.uk

www.mikewye.co.uk

One of the most strangely popular jobs at Camp Cob is digging, and believe me there is a lot of digging to do!

On site there is a large well stocked pond which is a result of the merger of the two original clay pits dug on site in the C18th to build the two existing Cob buildings. The hole we are digging at the moment is tiny by comparison, for now!

We are digging down past the top soil, tree roots and animal life to get to the clay beneath. The clay at Camp Cob is a silty mix, so we adjust our mix accordingly to account for this. The current sub soil we have at Camp Cob requires a 1:1:1 mix of sub soil, well graded sharp sand and straw. For us this makes the perfect mix, but it will be different wherever you are so make sure you do some tests. Some good reference points are:

www.edwardscobbuilding.com

www.clay-works.com

and Adam and Katy’s (from clay-works) book:

Building with Cob: a step -by-step guide by Adam Weismann and Katy Bryce

This July’s trip to Camp Cob had many visitors, two of which being Heinz and Marion a German couple who are friends of our client. Heinz was a miraculous one man site clearing machine as well as tree feller and married to a lovely lady with an eye for a good shower!

Heinz and Marion re-vamped our camp solar shower area into the splendid vision you see above. After a hard days digging or tramping on mud you can’t beat a warm shower surrounded by all the beautiful Camp Cob flora and fauna!

The view you see above is the fantastic view from our Tree Bog at Camp Cob.

A Tree Bog is a toilet that relies on the nitrate loving properties of plants such as: Willow and Nettles to break down the contents of the toilet in super quick time, meaning there is no need for emptying or moving of the toilet over time.

We have Nettles, Willows, Plum and Pine trees growing around our Tree Bog. A download will be available shortly on our website of a little ‘how to’ booklet should you wish to have a go at building one of these fantastic toilets!

This June’s visit is primarily for us to focus on the task of re-pointing the existing Flint plinth, which together with the existing Cob walls of the property had been unwittingly nearly ruined by a reinforced cement render which had been applied about 20 yrs ago. For those in the know, cement and concrete are a notorious problem for introducing damp and mould into buildings and for all permeable (breathable) building materials such as Cob, Straw and Timber it is particularly bad news.

For Cob it means that the cement traps water within the wall, which over time can literally wash the cob wall and mortars away. Luckily Cob is pretty tough stuff and once we’d removed all of the cement our Cob wall was still intact if a little wet!

Unfortunately the mortar of the Flint plinth took the brunt of the water erosion and had in many cases nearly washed away completely.

Instead of replacing the original Cob mortar we chose to repair and re-point with a 3:1 sharp sand and Lime putty mortar. This was to add strength to the new flint joints (as with a repair and not a rebuild you are repairing holes in a wall rather than rebuilding where you can lay the stones more specifically on top of each other to take downward loads), whilst maintaining the permeability of the Cob.

Wow! After two weeks of warm weather and rain, Camp Cob is pretty much lost in the undergrowth! It was so fantastic when we arrived to remove the vine that had grown over the entrance gate and push our way through. Myself, Vera and Tor spent the afternoon wading through 6ft high Rhubarb, Plum tree shoots and covered in Goose Grass, making paths so we could find the way to our fantastic Tree bog and to rediscover the Kitchen for the enormous quantity of tea which needed to be drunk.

In true ‘Where’s Wally’ fashion, the eagle eyed amongst you may just spot a Tor hiding in the jungle…

The Hastings Trust Pathway to Construction event was held this year on 5th June. It’s a great event where local builders partner up with local schools on a sustainable construction project for a term, the results of which are then judged at the event. We at Cave feel it’s really important for our UK construction industry to get involved with schools and help children to understand their environment better and to hopefully tap into and encourage any would be builders, designers and architects out there.

At this event Cave partnered up with the fantastic Amazonails (sustainable design and construction pioneers!) to run a stand all about the amazing potential of strawbale building! Above you see  Barbara Jones of Amazonails and Vera demonstrating the ease of splitting a strawbale in half, you just have to be careful not to get your strings crossed!

On Saturday 5th June, when most sensible people were fast asleep, Vera was up with the Lark and helping to build a Yurt. These beautiful, simple structures originated in Mongolia and Serbia with evidence of their use dating back to prehistoric times.

Vera and the team got this yurt up in  less than an hour!

Here are some interesting Yurt sites that we like:

www.theroundhouse.uk.com

www.woodlandyurts.co.uk

These are the amazing Net shops on Hastings sea front in the old town.

Vera and I went down to Hastings last weekend for the Hastings Trusts ‘Pathway to Construction’ event. Before we got stuck into that, we had a fascinating tour of the old town from Peter at ‘Chalkdown Lime’. These Net shops are the only buildings like this in the UK, built by fishermen to house their nets, they would have originally (before the new artificial beach) been on piers to allow the sea to wash up under them at high tides. Ingenious as well as beautiful!