Technically this is not a Thai building story, but it is certainly something anyone in Thailand could do. I actually got the idea while in Bali, where most low-budget accommodation is built from bamboo and grass matting.
I got about 15 bamboo poles from a local supplier, along with 10 lengths of Alang-alang thatch from Bali. The poles are all around 2m long and 50mm thick.
First I built the roof, which is an offset A-frame, longer at the front so it will shade people sitting at the bar. To make the ends sit neatly against other poles I used a 50mm hole-saw to cut right through them. This made them sit neatly, then I drilled through and ran cable-ties through the holes to bind them together. Traditionally it would be some kind of twine, but cable ties are far quicker. Once it was ready I used some twine to strengthen the joins and cover up the cable ties a bit.
Here I am choosing the location for the bar in my backyard in Sydney
Next I dug four holes for the upright poles. I just used a single bag of premix cement, enough to keep the bar in place even in heavy wind. Once set in place I used the hole saw again to cut them all to a level height (as the ground isn't level). The semicircles cut out of the tops allowed the crossbeams of the roof to sit easily in place while I secured it.
In the next shot you'll notice a few more diagonal braces, which I just kept adding until the thing wasn't too wobbly. The Alang-alang roofing was then cable-tied into place, which is very easy. Each length is wrapped around a supporting stick, which for such a small bar is rigid enough to need no extra support. You just start at the bottom edge and work your way up. The bar top I cut out of a piece of marine ply with a jigsaw, then routered the edges and lacquered it.
I finished it off with some bamboo screening as you can see in the next pic. Afterwards I made a bench seat in front of it with the leftover plywood and some treated pine. Since the ground is sloping I made the bench to suit the land, which is much more stable than barstools. I also made a floor out of hardwood decking I had left over from another project. Later I'll dig up a photo of the party we had to celebrate my weekend's effort.