I’m from south Texas as well and looking for this type of rig. Do you have any pictures? Thanks.
Not on hand, but I'll go snap some pictures over the next couple days while it's light out.
I read that it only takes something like a 1/4" over 10ft of a decline for water to flow downhill. Mine is about a 2 - 2 1/2ft drop over 60ft.
I used some split ring pipe hangers like this:
(Oatey 3/4 in. Galvanized Split Ring Pipe Hanger 33552 - The Home Depot
Bought some long threaded rod (you can buy 3ft pieces) and pipe support plates:
Oatey 3/8 in. Copper Pipe Support Ceiling Plate 33561 - The Home Depot
You should be able to put the hanger over the pipe attach the rod to the support plate and line it up each one to get the length and cut to size. Once you connect the 3 pieces, then mount the support plates with wood screws to the joists.
I stated at the low end so I know it would sit over the joists, (the lowest one or two I just needed a pipe strap). Then the high end, in the middle, and filled in between.
I want to say I spaced a mount over every 2-3 joists (4-6ft). The lowest few at the end were vertically up on top of the beam, and the higher ones were diagonally down off the beam.
The vertical pipe itself is about 4 feet inside the garage about 3ft vertical inside the attic. I connected it with a piece of clear flex pipe from the softener to the pipe. So I can see there is always going to be water in the bottom, (that gets flushed and replaced with new water every two weeks). You could use a larger pipe in the attic, but that vertical pipe to get there you want as small as what is suggested for more pressure and less volume. Inside the attic at the top of the vertical pipe, I want to say I used a 45 degree fitting, to a 90 degree fitting to give it a right angle to the back and was able to get my angle down.
In hindsight, I used PVC pipe, and I would have used pex pipe. With PVC I have couplers every 10 ft. They work, there are no problems, and it cost about $30-$40 in materials. Pex Pipe I want to say will be about $150, but its flexible, and you could make it one long continuous piece so there is no risk of leaking at a joint. With the pex pipe being flexible, I probaly would have wanted a couple more mounts and gone every two joists, but your call. (I'm a new homeowner, and I'm still making it a habit to go into my attic every few months just to take a look around).