Project Tipi - getting it together

Having found a lovely fabric to work with, 12oz duck cotton, actually getting it together is my next challenge. This is made trickier for only a few reasons, namely that:

1. The last thing I sewed together was a toy mole when I was eight years old
2. I only have my hands to use
3. I have no idea what a flatseam is
4. My chosen fabric weights a ton...and that's only about a metre of it.

Going back to the pattern, this is looking tricky...

The problem is that if I have to fold the fabric as in the diagram at the bottom, like some sort of corrugated tent origami, its going to be about a mile thick. Its at least 5 layers I reckon. That must require some sort of industrial strength javelin needle and a thread like rope.  The actual seem looks okay according to Candi but I am just not sure.

I think I might have to Queen Bee's sister about it, to see if her machine is industrial strength. If not, I think I will go and find myself an ebay bargain singer...at least Chris M likes a bit of sewing when is not singing so all might not be lost.