The Tyvek I used is from a 10' wide roll.
The pool will be about 7'x7'x1'
You will need:
4 - 8' long 2x4's
4 - milk crates (or something like a milk crate)
Bunch - Screws to hold the 2x4's together
Staples and Staple gun
Oh and a big piece of Tyvek (I used 10'x10' piece)
Staple one edge of the Tyvek to a 2x4... all along the edge (ever 6").
Roll 2x4 till Tyvek is wrapped around the 2x4 one time.
Repeat Step 01 on the opposite end of Tyvek
Set out the milk crates in a big square (about 7'x7')
Set the two unused 2x4's to make the top and bottom of the pool
Set the two 2x4's with the Tyvek on top of the other two so you have a big square with the 2x4's
Get in the center of the pool and flatten out the Tyvek so that it goes all the way to the corners. The walls need to be straight up and down (not tight, water will rip it apart)
Measure in about 6-8 inches on the ends of the 2x4's and screw the ends together (See pic)
Lay the two naked edges over the last two 2x4's and staple the Tyvek
The Tyvek rips really easy with the staples so use lots. I also found that if you put a piece of cardboard over the Tyvek and staple through that... it helps a lot with ripping.
Start filling with water and attach the milk crates to the corners of the 2x4 square. If the milk crates slip out from under the 2x4 edge... a lot of water will flood your yard.
Make sure you have as much Tyvek on the ground and the edges are pretty straight up and down. You don't want to hammock the Tyvek, use the ground to hold the weight... the Tyvek will just hold the water in.
If it's to cold for you... put something dark in it when you arn't playing... I used a dark blue yoga mat... this will heat it up faster than just the sun.
This pool will last about 5 days if you are nice to it... if not, considerably less.