Archive for March, 2012

I was asked the other day whether I had any advice or tips for earthbag building. I’ve copied some items from a previous article I’d written and added to it. These are some of the (often hard earned) lessons we’ve learned and suggestions based on our experience:

*Build a ‘trial’ structure first if at all possible. It can be a shed, a sauna- just something small that you can get some practice in on. The time it will take to build something small will undoubtedly pay off in time saved (and lessons learned) on your future home.

*Nail down the barbed wire to keep it from moving, fence staples work really well. There’s a tip for holding down wire using twine and bricks in Doni and Kaki’s “Earthbag Building” book that’ll work if you’re really trying to keep costs to a minimum but our own experience is that the staples are worth the cost.

*Rinse the cement mixer immediately after use, and at least once during the day, for easier cleaning. Don’t own a cement mixer? Seriously consider buying a small one- the time you’ll save is more than worth the couple hundred dollars you’ll spend. It’s my favourite tool.

*Mix gravel and cement first, dry, and then add clay- so that the clay doesn’t just stick to itself. Presift the clay into wheelbarrows so that there’s lots on hand.

*Be careful with moisture content. You want the mix damp enough that it will form a brick once tamped, but not wet enough that water leaks from the bag when tamped, or wet enough that the bag changes shape under pressure.

*Tamp the sides of tubes/bags, not just the top. This will eliminate that wavy look that you see on some buildings and drastically cut your plaster.

*Always feel the mix with your bare hands, soil-clay and gravel may differ slightly from mix to mix. Wear gloves in between to avoid rubbing the skin right off your hands.

*Trust your instincts and communicate (e.g if the mix feels wrong, even if you’re not the one mixing, mention it).

*Cut tubes a little long if using tubing. If you’re using bags- turn them inside out and stack them ahead of time.

*Fill tubes straight, and twist along arc. Don’t try to fill them ‘on a curve’.

*Use good weather and daylight for building, bad weather and evenings for prep and planning. Have a well formulated “to-do-list” and check it often.

*Don’t make plans/commitments during the building season and be prepared to be a weather watcher. No matter what amount of time you’ve ‘reserved’ for building- it will probably take longer than that.

*Keep duct tape handy for rips or punctures.

*Don’t pretend all things are equal- if it’s too heavy (Brandee!) don’t lift it, if you’re better at something else- do that.

* Gravel piles look like giant litter boxes- keep cats off site. Seriously a good tip.

*Have lots of buckets on hand for transporting mix.

*Scavenge throughout the year- start now. Instead of strictly looking for things that you know you need, ask yourself “what could this be?” about the materials you come across. You may be surprised.

*Prepare meals ahead of time. There is nothing quite like putting in 12 hour days on the site only to have to come inside and prepare dinner instead of collapsing in front of an already made meal.

*Get in shape prior to the build. Unless you’re one of the lucky ones, with a team of six or more people- this is going to hurt. Better to be prepared for it.

*Mix up tasks to work different muscles. Prepare mixes for a while, tamp for a while, sift clay for a while- even watering the garden occasionally will help keep your body as strong as possible for the work day.

*Lower levels can be worked by a single person but the higher you go, the more likely it is that you need a partner.

*Remember the importance of compression. Do not tamp 2 or 3 bags at a time because you’ll lose some of that tension. I did that once I got up fairly high on the wall because it was easier to manage alone but the rows did not come out as strong and sections had to be replaced. Also- if you have to leave a row unfinished- tamp a puzzle like shape into the end of the bag where you’re leaving off. This will give your next bag something to key into when you come back to it.

*If you get summers like ours, you’ll be tempted to wear sandals instead of a heavier shoe. My experience with this is that sandals can get stuck on barbed wire and come right off on the wall, leaving you barefoot and navigating a barbed wire wall, quite possibly while carrying heavy loads. Equally fun and considerably more painful- accidentally tamping bare toes.

*Round is sound- round rooms are the strongest you can build, but make sure to use a centre pole. Check and recheck your measurements on a regular basis. If you are doing straight walls, make sure to check they are actually straight as you continue adding rows and build in buttressing to support the walls. Don’t attempt irregularly shaped rooms. We haven’t tried them ourselves but from what we’ve seen of others’ experience, it rarely works out well.

*Stagger (offset) bags from row to row to add strength to your walls.

*Plaster as you go, every few rows or so. You need to protect your bags from UV damage but you also don’t want to be trying to plaster extremely large areas in one shot, because again- it’ll take more time than you’ve estimated.

*Chances are you will have some sections that are a little low, or a little high. It happens. If you’re a bit low overstuff the bag that lies above it, tamping the mix into the bag as you go, so that it tamps down a little less than a ‘regular’ bag once you lay it. Conversely, pack the bag a little looser for a thinner bag.

*Bear in mind that the window and door forms are going to have a lot of pressure (from tamping) coming in on them. Put supports inside the forms to keep them from warping. Also- build your doorways wide enough to fit any furniture or appliances through (oops!).

*If you are at all lacking confidence in producing your own building plans along with all of the accompanying calculations, there are some very good and extremely reasonably priced plans on the Earthbag Building site, available either in PDF format or AutoCAD files.

*If you are producing your own plans- plan for everything. You want to consider everything from sun angle (for solar gain), to predominant winds (for passive cooling and ventilation), venting for batteries if you’re going off-grid, building in nooks for storage of aesthetic purposes, views from windows, water capture, proximity to other structures on the property… There is a lot to take into consideration, from site selection to the actual building. Take your time and review your plans several times.

*I’ve found that my work day passes a lot more quickly when I have my MP3 player loaded up with a mix of interesting podcasts and good music. A bit of a side-note, if you’re going to work in your underwear and wear headphones it’s a good idea to look up every now and then to make sure you’re still alone. Then again, you’ll get your road graded a lot more often if you disregard this tip.

* Also, the Wonderwoman (or Superman) complex that you will inevitably develop after a really good period of building is a little dangerous to entertain for extended periods of time. My new rules include: if there’s blood involved it’s a good time to break, and if it really hurts try not to do it more than three times in a row.

I think that’s about all that I have. The earlier in the season that you start building, the better obviously. Things like rain-days and days when the temperature is above 35 degrees will definitely impact your plans, as will unexpected injuries. Leave yourself as much room as possible.

Oh, and don’t forget to congratulate yourself on a regular basis. You’re doing something a lot of people will never experience- you rock! Happy building!

Our roof is double anchored because we're in a high wind area

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