Replacing Liner - Drain to measure?

[AndyT86]

After a couple of seasons with different leaks, I've resigned to replacing my liner. Different manufacturers have different forms for recording measurements, and more than one manufacturer's form says to drain the pool to get the measurements (e.g., diagonals in the hopper of the deep end). However, I remember reading (years ago) that you should not drain a liner pool except when replacing the liner. (I think that Ben even mentioned having ideas on how to replace the liner without draining.) So here are my questions:

Is it okay leave my pool drained for a couple of weeks while the new liner is being manufactured?

Is filter sand okay to fill any divots in the floor under the liner (presumably caused by the leaks taking sand away)? If not, what grade or kind of sand to use?

I'm reading in the forums that 20mil is easier to handle, and just as durable as the 28mil. Is that the general consensus?

Gotta order this weekend, so any advice is appreciated.

Thanks,
Andy

[waste]

Andy, as long as you are replacing the liner it should be fine to leave the pool empty while you wait for the new liner - the big problem with letting a liner sit empty is if you plan to refill it, it probably won't have the stretch left in it to fit right. Your sand bottom gives you a little room for error on the measurements but if they are way off you could end up having to move, remove or haul in a lot of material and do a lot of troweling . You can leave the old liner in place until the new one arrives to help protect the bottom from rain, etc. When you take the measurements for depth, you can run a string across the pool, secured at deck level, measure down from the string to get the depth (** remember to subtract the height of the coping, the wall height they want is only to the receiver for the liner's bead!!**) Take a bunch of depth measurements, try and find the high and low spots and average them, you'll have a much easier time of troweling the bottom the less material you have to add or move. Also order the liner a little shallower than the depth you get, the liner needs to stretch into the pool or you'll end up with wrinkles .

I hope you have a 'regular' shaped pool, if not let me know. Assuming a rectangle with an ~8' hopper and 90 degree corners: take the length and width, do it from right and left sides and shallow and deep end (don't just assume that the pool is the exact size you were sold - an 18 X 36 pool could well be ~18' 3" X 36' 2") and get the diagonals so they know if the pool is 'squared' properly. There are 6 other points to worry about the first 2 define the transition from shallow end to deep and should be parallel to the shallow end wall, measure from the wall!, if you need to cut a small slit in the liner to get the end of the tape on the wall, do so. I drive a rebar pin into the ground (through the liner) to mark these points (this way they are already set when you string out the bottom to trowel it before dropping the new liner). Now you want to find the 4 points that define the hopper, this can take 2 tapemeasures and a plumb bob.(if you need more on this, just ask, I'm babbling on enough on things you probably already know )

As for any patch/ fill sand, the finer the better, just be sure it doesn't have any stones in it.

20 mil is fine.

Sorry to take up so much time with this post, but I want to make sure your new liner goes in without a hitch, I've replaced hundreds of liners, so if you have more questions during this process, just let me know and I'll tell you what I know.

[AndyT86]

Thanks for the great info, Waste! A couple of follow-up questions:

Also order the liner a little shallower than the depth you get, the liner needs to stretch into the pool or you'll end up with wrinkles .

How much shallower? If my shallow end measures 41-1/2, do I order 41? 41-1/4? 40-1/2?
Do I use the same "shortage" for the deep end? If it measures 100, do I order 99 or 99-1/2?
Do I only measure the depth short, and give actuals on the perimeter and diagonals? I guess I'm trying to figure out how much stretch to design in. I know it should fit more like a latex glove than how my kids like their jeans.

I hope you have a 'regular' shaped pool, if not let me know.

The pool has a Grecian shape with Grecian Hopper. With no water in the pool I think I can get the other measurements. The edges on the bottom are not well defined, but I like your idea of using rebar pins to mark them.

Thanks again!
- Andy -

[waste]

Andy, I have no problem sharing what I know to help the members here! I responded to this this afternoon, one of my typical long- winded posts, but somehow it didn't get posted (probably my fault, I must have hit preview instead of submit ) Oh well, look at the bright side, I can boil it down and just give the info without so much rambling/ disorganization (if I boil it down too much, just ask for a little more info on anything I say)

1/4 - 1/2" should be good for the shallow end, remember that the floor is probably not level, try to shoot for that amount under the average depth.

Grecian hopper means you have 6 points to establish to make the hopper floor. Keep the edges of the hopper floor parallel to the side/ back walls - it'll make the liner easier to make and fit into the pool. Because the sand has a tendency to 'disappear' over time, you might want to expand the floor of the hopper and use some of the extra to fill in where you will probably run short on sand at the bottom of the slope/ hopper walls - if by some chance you end up with some extra sand by doing this; it's easier to haul a few buckets of sand out of the pool than top have to run out and get more or try to blend into the voids! If you have a MD, that's going to have to be the level of the floor.
Remove any stones you find while troweling!!!!!!
The wall measurements should be sent to them exact, they will do the undercut so it fits correctly. Also send them both sets of diagonals (side walls and end walls), cause many installers have trouble properly squaring up a Grecian pool.
While the pool is draining you can watch the water level on the floor, slope and walls to see large humps and voids.
Right now the concern is measuring the pool properly, but keeping some of this stuff in mind will lessen having to pull a bunch of material out or bring a ton+ of sand in and apply it - when the time comes to string out the pool and retrowel the bottom, I'll give more advice as needed
I STRONGLY advise procuring new gaskets for the skimmer(s), light(?) and MD(?) and new faceplates for everything (& screws if needed) - a new liner just looks better with new faceplates and shiny screws.
Do you have stairs that the liner goes over? - if so you've got to send them the EXACT stair dimensions so that you don't end up with wrinkles.

That's about what I can remember from my 'lost' post - if I think of anything I neglected I'll add it - if you need me to expound or clarify on anything, just ask