We just had a 40x16 installed. The liner is not flush where the wall meets the floor. You can push on the liner. Its a 3 to 6 inch gap and around the entire pool. You can also see they didn't bother with trying to line up the liner. The installer says it's not a problem and the only way to have a liner lined up is if you get a fiber glass pool. Is the liner not being flushed an issue? HELP please and thank you!