I am going to install the new liner my self with the help of a few friends as free labor. My Doughboy folds over the top of the wall edge and has a approx. 4 foot plastic clip that slides down over it to make the wall connection. I have watched a half dozen or so videos on YouTube that show liner replacements and am comfortable doing it. Also I have noticed liner thickness from 20 gage to 30 gage with 30 being the most expensive and I assume the thickest. Which do you recommend? This is a bit confusing because I am familiar with using sheet metal that is measured by a gauge system. In metal the lower the number the thicker the sheet. It seems the pool or vinyl industry are using just the opposite to rate the thickness of their products!