Getting ready to install expandable liner

My 21' Round ABG pool is sitting about 1 1/2 feet in the ground, fully assembled and my liner was just delivered. My pool site is loaded with all kinds of debris from the new construction (just built a new house) and I've done my best to clear out all of the rocks, bricks etc but no matter how deep I dig, I keep finding more. As a result, I've got foam cove, a gorilla bottom and about 3 tons of sand. I'm planning to put in the sand on the bottom and then the gorrlia pad on top of it. I'm hoping this will prevent any problems with my "rocky" bottom.

The liner is a 60' expandable overlap liner I got from swimmingpoolliners. The pool walls are only 48" but I've dug out the middle about another foot. I was planning on using Dennis' method for installing the liner, by placing it over the seating rails and holding it in place with binder clips, filling it slowly, releasing the clips a little at a time and then removing and replacing the top seats when it was nearly full. My only concern in the strength of the walls. It seems like the weight of the water might collapse them inwards towards the center of the pool. Am I just overeacting?

Secondly I was also going to apply roofing tar to the exterior of the pool since it sits below ground level. The entire pool will eventually be covered by a deck so I'm not concerned about how it will look. I figure if I can get 10 years out of this pool, I'll be happy. I assume I cover both the walls and the bottom rail with the tar for the best protection?

I didnt take pictures of the intitial excavation but started last night once I finished the pool set up. I will continue and then post them if anyone thinks they might be helpful.

I would appreciate any comments or suggestions you may have.

Hi, Expandable liners are a real hit and miss thing. I can install a Doughboy brand expandable liner into a deep area wrinkle free just about every time. The key is that they are expandable. They fit a flat bottom pool just as well as one with a three foot deepend.

Then there are what I call glad bags. They are just extra big and are usually extremely baggy. Wrinkle free never happens. Just about the time the water gets out of the deep end we are in the pool smoothing the wrinkles.

My method is still the best for both types. I hope you get a good tight wrinkle free fit.

Be sure to start with lots of sunlight and best of luck, Dennis