EcoDIY Eco-house

Making a Geodesic Dome

1/ Sticks;

You will need 35 long sticks and 30 short sticks.

Sticks can be made out of broom sticks or metal pipe but I prefer to use coppiced hazel, ash or willow. The diameter of the sticks is in proportion to the size of the dome i.e. two to three centimeter range  for domes up to about five meters across.  two and a half to four centimeters for domes up to seven meters across. All these sizes are for guidance only and not a rigid rule.

Properly coppiced sticks are the straightest - try your local Nature Conservancy organization for coppice woodlands or keep an eye open for wooded farm land.

Size of Sticks;
To work out the lengths of the sticks (bolt hole to bolt hole); Divide the circumference (Diameter times 22/7) of your dome by 10 this will give you the length of the long stick .

The length of the short stick is the length of the long stick minus 11% (i.e. the length of the long stick times 89/100.)  For example the lengths for a four meter dome are 1257 mm and 1118 mm 

You will need 35 long sticks and 30 short sticks.

Stick ends

I make these of blue plastic water pipe (the sort that comes in 50 meter rolls)
You will need 130 pieces of blue pipe about 3" long (I cut mine with a circular saw)
You will need 20mm pipe for smaller domes and 25mm or 30mm for larger domes.

The pieces of pipe need to be flattened over half their length (See diagram). To do this use a hot air gun or hot engine oil to warm the pipe and flatten it between two blocks or in a clamp or vice.

Fitting the Stick Ends

Whittle the stick ends to be a tight tapered fit in the pipe ends (use a sharp hatchet or adze) Knock the ends on and secure by screwing  or nailing through and bending the point of the nail over (See diagram).The sticks need to be cut to give the correct length between the bolt holes. Drill the bolt holes through the plastic to take a 4mm galvanized gutter bolt.

You will need 26 4mm galvanized gutter bolts 60mm long, nuts and large washers.

The dome is erected in the pattern shown in the diagram.

Cover

To cover your dome you will need either;

A square cover the length and width of half the circumference of your dome plus one or two foot as a tuck under allowance i.e. 7 meter square for a 4 meter diameter dome. or a fitted cover.

The cover can be made from; Reinforced plastic sheet (cheap but noisy)

Second-hand canvas from your local government surplus supplier (watch out for canvas that is too heavy) second hand marquee canvas. Or

New canvas: a good supplier in the UK is; Lows of Dundee PO box 300 Marrbank House, 
6 Paradise Rd, Dundee, DD1 9JK Scotland UK, phone +44 (0)1382 229251

The canvas I used was 393 gm per meter or 251gm per meter rot and water resistant cotton duck.

  delivered in 100 meter rolls but this is now superceded by polycotton.

To make my own fitted cover I used a domestic sowing machine (with linen thread) and set up my frame and marked out the canvas on the frame (allowing 1" overlap for the seams) the seams are simple overlap with two runs of stitching.

Erecting your Dome

1.     Start from the middle, Lay out a ring of five longer sticks and link them with five short sticks to the centre.

2.     From each corner of the pentagon put out five short sticks linked at one end (to make star shapes) attach one stick of each star to the corners of the centre pentagon

3.     Lay five long sticks around each of the stars made in step two.

4.     Bolt through these long sticks to include the ends of the star short sticks apart from the ends that will connect to the ground level ring (get someone to help by lifting the frame as you bolt through.)

5.     Complete the ground level ring of long sticks bolting to the pentagons you have just made; you will need help again to lift the frame as you fit the bolts.

6.     Cover with your tarp lining up your tarp door opening with a larger triangle and tuck the surplus tarp under the frame.

7.     Peg in the guy ropes if you have any on your cover

Happy camping