With the construction of the base structure I had to remember that I live in northern Europe and that the climate is quite harsh for 5-6 month .We have sub zero temperatures , a lot of snow and sometimes blizzards.
Therefore, whit this in mind I had to make it well insulated and very tight so that snow and water could not get trough it.
If you live in better climates some of this points mentioned are totally unnecessary, but this is totally up to you
for the construction of my dome I started quite appropriate with the base structure, as I could not build it totally round I opted to make it as an octagon.
First I casted concrete piers on witch to place the construction then I begun with the floor , this is made as a separate section much resembling a wheel
I then placed the wall skirts , the wall is 50 cm high but depending on your type of scope it could be higher or lower.
Between the inner walls and the outer facade I put 10 cm of insulation.
It must been said that there is no drawing for this bas structure at Joe’s homepage but if you want one just mail me.
With the base construction done I placed a base ring on top of it (this is the base ring mentioned in Joe’s drawing for putting the dome on) this means that I had to make two rings one lower to place on the base structure and one upper to place the dome on) these were made of 20 mm furniture plywood (10 layer plywood extremely durable) and painting it with one layer of boat epoxy plastic to prevent it from rotting.
Remember that working with epoxy is hazardous and you have to wear protective masks also the wood has to be completely dry otherwise you will trap moisture into the tree and then it will be destroyed.
On the base ring I put 20 small wheels and a strip of styrene foam (5*5 cm) was glued to the ring.
This foam was glued in place with the same glue I used to the dome it’s special contact glue made by Bostic.
The reason that I put the strip there was because this is a point where the wind will have plenty of room to venture inside your dome even if you have the side skirts on, believe me.
You as well as I will learn by your mistake. But then again there has to be a 5 mm opening still because otherwise the upper ring will get stuck.
The skirts are made of Masonite 10cm wide (to cower the upper ring, opening and go below the base ring 1 cm), this is very important because otherwise the rain will be able to get trough in stormy weather.
With this mounted I painted it with epoxy plastic (but any 2 component boat paint will do fine)
Then there has to be a skirt on the inside but this is not to be as wide as the outer but 6.5 cm will be enough, this is to prevent the wind from the 5 mm gap to get into the dome and to prevent peoples fingers to get stuck in the wheels.
Now the base structure was snow, water and windproof.
This completed the base construction all that was left was to paint it