Roofs

Considerable thought has been given to roofing on the various designs we've come up with. For our little house we like designs that are domed - the build is a little easier for the flexibility of the space the provide. Plus there are pleasant hobbit-hole connotations. However, it tends to get quite wet here in winter and earthen plastered domes don't do well in wet climates. In fact, 'big hat' tends to be a rule-of-thumb buzz word for earth houses.

It also occurs to us we'd like to collect water from the roof of our house, which is hard to do with earth plaster.

So I've been looking into roofing on domed earthbag structures. It seems there have been a few people who have experimented with this already.

Many variations on ferrocement moulded hat-like roof structures:

Several that have incorporated moulded guttering into the structure of the dome itself:

One that I've found with corrugated iron raised up from the dome:

And the all-time stylish favourite, shingles!

Originally I was trying to work out something similar to the corrugated iron dome, but I'm fairly severely arachnaphobic and can just imagine how many cobwebs would end up in the gap between. I was in the process of working out how to close that gap by bringing the corrugated iron close to the dome and plastering any openings, but at that point began to wonder whether attempting to bend the metal and cut it just right to size would be worth the effort - in such an organic structure surely there is a more organic solution to roofing. Which leads us back to ferrocement.

My biggest concern with ferrocement was lack of waterproofing, necessitating a coating of some sort. Early searches into types of paints and sealants suggested to me that many would result in small amounts being mixed with any water collected from the roof over time. Plus it's just another material we'd have to buy, learn how to use, apply, and maintain. Simple is best

But then I discovered magnesium cement. I still have a bit of homework to do on this one, but it seems a viable contender as a roofing material that is flexible to the more organic shapes of the domes, waterproof, and suitable as a surface for water collection.

We're still collecting!

We found our floor!

1' square slate tiles, a little over 100 of them. I haven't worked out what that is in square meterage yet, as there are several of them that have been cut down to various sizes so it may be hard to tell for sure. We're not too worried if we come up a bit short, as we'll just fill the gaps with other interesting bits and pieces we find, but it's good to know for planning. They also need a bit of a clean up as many of them still have bits of grout hanging off the edges. We snapped this set up for the grand sum of $50 from our friends at the tip.

I'm not sure if we've mentioned in the past how much we love the tip. There are 2 in the city we live in, both with warehouses off to one side where they sell off anything they can that comes their way and give the proceeds to a different charity each month. We embark on our weekly pilgrimage usually sometime on saturday afternoon, after all the weekend renovators have emptied their skips but before the sunday-morning hoarders arrive.

Preparation

There are many aspects of a project like this for which Kyle and I are not really sure what to expect. Personally I think that's part of the fun of it - who wants to live a quiet, comfortable life anyway? However that does tend to lend itself to a bit of risk. We don't want to get to the point where we're lying awake at night ravaged by thoughts of "what if?" (well, not too much).

What if it turns out we're no good at earthbag building after all?

What if we can't find all the pre-loved materials we need for the build?

What if the banks won't give us a mortgage on land for a project like this?

Most of these big "what if's" we can deal with in advance by doing our homework and being careful about what we commit our resources to before we move to the next step. But sometimes doing your homework on what others have done before us isn't enough. Sometimes, we just have to get obsessive about the details.

What if we can't actually survive on solar panels?

Quite some time ago I had assumed we'd need to build our own fridge eventually as part of this project, so we weren't particularly concerned about having to ditch a few appliances. It does seem necessary, though, to be able to quantify our electrical needs to work out whether we need to replace core appliances with models that place less load on the system.

Enter our new electrical usage monitor:

Obviously I've got our electrical bill for the past however-many years we've lived here, with its helpful little graphs comparing our 2-person household with others in the area, but the value of this information is extremely limited as it includes things like heaters and fans, the use of which will be very limited in the new house, and the inefficient light fittings that our landlord refused to let us replace. So, over the next few weeks I'm going to track our electrical usage in as much detail as I can so that we have a realistic quantitative picture of our electrical usage in preparation for the switch.

Maybe it's the science teacher in me, but I never feel like you can have too much data.