Geodesic domes are known for several benefits. Those benefits are many, expounded on in other blogs on this website.
But for all the benefits of a geodesic structure I discovered this much - they are very unforgiving. That is, if your work is out fractions of an inch you will know about it. The dome will not let you forget. :o
Which is why I’ve changed my work methods to adapt. First, I’ve gone completely metric. Now I speak “metric-ese”. No more 1/16ths of an inch for me! Going metric has made measuring and subtracting lengths so much easier as well and since I never cared much for subtracting fractions this was an easy adaptation.
Second, I’ve decreased my error tolerances. And THAT has led to another discovery. Existing lumber comes in dimensions that vary considerably. That is, regular construction lumber that is supposed to be 2x6 will differ based on moisture content, whether it's kiln dried and some lumber sits in the lumberyard for months, some for days. Some suppliers store their lumber indoors, some outside. So what you get is somewhat of a crap shoot.
Considering that most lumber is used for house framing, where errors of a ¼” are routine the differences don’t matter much. And as we know the house building industry is more about mass production not precision cutting, unless of course we're dealing with finish work.
The solution? Buy lumber that was stored indoors, double check the dimensions before using the piece and in some cases run it through a plane. To many woodworkers this is all ‘over the top’, but to an anal carpenter like myself, it’s all part of putting out not just a wood structure but a work of art. :)
To build a geodesic dome in the style chosen by GeoStudios, one needs to build a floor and walls that match the shape of the dome that will rest on them. That means a ten-sided floor in the shape of a decagon and wall panels that will match the perimeter of that floor.
As I move towards building the campsite model dome, I graduated to the next step, building the walls. It involved a lot of cutting at not-so-typical angles.
The first angle I dealt with were the top and bottom plates that need to be exactly 18 degrees. That requirement wasn’t too hard but the ongoing double-checking to ensure everything was on track took longer than just a usual “saw and nail" routine. In fact, “measure twice cut once” takes on new meaning when building a geodesic dome. For the mathematicians among you, that 144 degrees in the picture at left represents the inside angle, not the cutting angle of the plates.
The other 'atypical' cut had to be the vertical sides of the studs. They had to be ripped (cut lengthwise, in this case on my table saw) just a smidge. That angle cut now matches the 'curvature' of the 10-sided wall system and ensures the studs don't 'stick out'. Otherwise it would be a pain in the keister to put plywood on the outside without a lot of wood to screw it into.
The last cut was with a a chop saw to crosscut all the stud pieces to the same lengths, 1000mm or 39ish inches. And after that a coat of wood primer. The result is a pretty pile of wood :) waiting to become the walls of a decagon.
Finally, assembling that pretty wood to make the 2x6 "walls". There will be 9 pieces. Did I say 10? Oh yeah, the 10th wall panel will actually be a doorway so it's not actually being built. Ultimately, those 9 walls will be connected together, sheathed on the outside and to live up to it's roasty toasty reputation, insulated with R14 value insulation. More on all that later!
It’s been cold and snowy like I haven’t seen it in a long time. Well ok, since last winter. This is GeoStudio One’s second winter and I have numbers! Last year on the coldest nights I used about 70 cents of electricity. (As an aside, yes it does seem cheap and the high insulation value and the size of the dome are key factors that kept that electricity cost down.) If this were a tiny house, your electric heating bill would be under $50 per month in the coldest months of winter. That’s not a fair statement though since after all the administrative fees and extra charges are added in it would be closer to $100 with a regular grid hookup. Which is a good segway into the heat source I got for this winter - a propane heater.
A tiny vent-free CSA propane heater, together with the 100 lb tank was a $675 investment. These however are one-time costs and there won’t be recurring administrative fees. :)
The fuel was an extra $70 to fill the tank on November 2nd and that tank was empty by January 4th. So my propane heating bill through at least one week of -25C temperatures was under $40 per month. And NO administrative costs. This little unit kept the dome roasty toasty 24/7 through the coldest days of the year including record-setting minus 37 on New Years Eve.
So my forecast for annual use would include no more than two more refills to take care of heating from January to October. That’s a rough average of $14 dollars per month. Not bad.
This heater (or one very similar) will be in the GeoStudio dome at the campsite, in Good Spirit Acres. Camping in comfort, that’s where it’s at!
Gilles Leclair is the founder of GeoStudios. Somewhat eccentric, fairly environmentalist, politically aware, he believes the world should have more off-grid communities... many more.