1/2" EMT plastic pipe is way to flexible; even 3/4 can be tough. Bracing and brackets are tough and time consuming!
I use 1/2" EMT....Metal pipe...4M's just fine last year...I made a 5 M mega tree this year, looks fine but I haven't put it up.
In one case I use my house wall to hang the pipes. I attach a short length of 2x4, pre-drill and put in eyelets. stagger two rows: say you have 10 lengths of pipe; 5 eyelets in row one, 3/4" spacing, and behind the first row of eyelets put the second row of eyelets about 1" back. This way you can get the pipes or tube very close together. The bottom is a length of PVC that I Bow into a "D" and tie the pipes to it with Nylon Ties.
My 5M tree hangs from a pipe I put up: very simple setup; 3' sleeve pipe set in the ground and I inset another pipe into it to make a mast....about 20' long. Got the pipe from a fence supply company. Cheap and easy. If you put it in your lawn, the sleeve pipe should be below the grass.
The trick for using metal EMT is to take a 2"-3" length of 1/2 diameter wooden dowel and hammer it into the ends of the pipe. Then pre-drill hole and screw in a hook (using #6 or larger; don't go nuts). On the top of my mast I have a piece of 2x4 and do the same thing as before with the eyelets.
The photo isn't very good, but you can see the 2x4 and the pipes. I cover the top of my tree with a plastic cup "rose" with 25 rgb led's.
I have winds up to 60 miles/Hr up here in the winter...never had a problem with the Mega trees.
