Update on mortar work

Amber and I finally shared our first morning of muddy messy masonry yesterday. These are some pics of the process. The idea (which only time will deem brilliant or idiotic) was to dry-stack the bottom two courses very carefully and only use the natural (meaning water sensitive) mortar once a safer height off of ground level was reached. This would keep the vulnerable mortar and the cob ring above it away from potential surface water while adding extra breathability to the structure's base. Moisture seeping into the draining rubble foundation could evaporate and be carried out of the oven's base via airflow without threat of interior condensation (often more threatening to structural integrity in cob walls than exterior wetness due to the constant saturating damp it creates). All of this is likely completely unnecessary over-thinking for a simple oven project. That said, it is in keeping with the spirit of experimentation and self-education of this leg of our journey. We intend to make good use of every lesson learned in this relatively low-risk endeavor, so why not? You get out what you put in.

We started by running the desired portion of decomposed granite (We have a pile of neglected leftovers from the construction of a foot path years ago) through a 4'x4' wood framed piece of hardware screen (wire mesh) that has been temporarily suspended from a conveniently located live oak. The granite has far too many large pebbles and rocks to serve as a mortar material in its natural state, but once screened, provides a beautifully varied spectrum of super sharp aggregate that locks into a very stable matrix once a bonding agent (in this case clay) is added and mixed by foot to the right consistency. This was our first run at screening material and the system proved to be functional but still needs some tweaking. I was experimenting with a flexible frame design that showed some promise initially, but proved too finicky in the long run. I got a grueling education in the economy of labor required by manually screening massive amounts of sand and gravel while working on a basic water filtration system in a rural village in Peru several years ago. Anything that requires constant adjustment or breaks the flow and rhythm of the work is usually not worth it.

[Side Note: If you are a traveller or concerned global citizen and have never heard of Hands on Disaster Response, do yourself and the rest of the world a favor and take a minute to check out their web page @ http://www.hodr.org/ This organization is AMAZING. Amber and I spent a third of our three month Peru trip with them after the earthquake three years ago. This is not another pay-to-play volunteer organization where you can feel good about your vacation time by paying someone to let you work for them, and maybe do some good in the meantime. These people mean business. You pay your way there and they feed and shelter you for as long as you can commit in exchange for your willingness to work HARD, all day, six days a week, hand in hand with locals trying to put their lives back together after shattering tragedy. In my 20+ years of world travel I've never been so impressed with an organization or a self-selected group of volunteers. We made some life-long international friends from this experience, some of whom will be at our wedding in Oct. Nuff said.]

So, I will sure-up the frame before the next batch. Once we had the right amounts of screened aggregate and clay-based sub soil portioned out on a mixing tarp, we lost the shoes, cranked the bluegrass tunes, and danced our first muddy mix'n jig. For those of you unfamiliar with cob building and tarp mixing techniques, think the whimsy of mud pies, puddle jumping, music festival dancing, and traditional grape-stomping mixed with the attention to detail and multi-sensory input of a potter's wheel or a painters pallet. This is 'serious' fun in the fullest sense, and it was truly special to finally share the sacred mud dance with my favorite human.

The actual rock work went pretty slowly, something I'm finally getting used to. Its all unfamiliar ground for both of us every time we reach a new phase of construction. Taking our time allows us to learn everything there is to learn from each action, each movement. It can be frustrating for sure, but it is also rewarding in a sense adults don't often get to experience in our world. By using concrete the entire foundation could have easily been built (even by us) in a day or two max. Although this kind of speed and ease of labour sounds like an obvious winner, the sacrifices and compromises for a project like this one are too many and too subtle to list. I will be writing more about the role that concrete and lime play in my projects when we tackle the garden cottage's foundation.

We started by working out from behind the accent stone (the one standing on end). This is the trickiest, most delicate, and most visible section so it only made sense to start here. It is sometimes tempting to hop around the ring trying to find the right fit for that perfect stone you already have at hand. Although this can be instantly rewarding, it typically means a lot more work in-filling the gaps created between these 'perfect' fits because the size and shape of the gap has already been determined. If you only work out from one point in each course of stone(either direction or both simultaneously is fine), then there is only one place (when the course meets back up with itself) where your options are limited in this way. Make sense? Sometimes its worth it, most of the time its not.

We are using the mortar more as chinking and irregular bedding than what I understand to be typical for stone work. There are risks involved in this, but so far the trade-offs, like avoiding concrete, seem to be favoring the decision (only time will tell for sure). It is much slower than the slop and plop style typical for brick or mortared stone because the stones still need to be carefully placed in stable positions. They are essentially dry-stacked with the mortar adding stability and support. So far it looks and feels very sturdy.

OK... I'm done looking at his screen for today, but I'll pick back up later. Sorry there aren't any photos of the mixing. We were too busy enjoying, but there will be lots of photo opportunities to come.