I am about to start my 20x40 vinyl liner type pool.... I plan on pouring cement in the shallow end but do I have to make the deep end out of "dry pack", or pool krete?? Can it just be sand?? No one will walk on the deep end so it should stay smooth.... I have heard of people that have the entire floor bottom out of sand... So I justcwanted to get all of your thoughts on this... Any info is appreciated!!! Thanks!!

Either vermiculite or pool krete over the entire bottom. Don't mix bottom types. Pool bottoms are fairly difficult. Even ardent DYI'ers hire out pouring the botttom.

I understand your tackling an enormous project with a DIY IG pool and you are bound to have numerous questions along the way, but you might consider using the search features here. Most topics you have posted has been discussed in great detail.

Just sayin...

I did mine in pool kreet and found it very difficult to keep smooth. Although it looks very good underwater

bk406 speaks the truth! Do not mix types and, especially, do not take the successful finished floor lightly.......it can be very troublesome for DIY.

I believe if you tried mixing the types, you would end up with a nasty transition problem where the two types of floor material met.

Ok thanks!! What do you mean by nasty transition?? You think it would separate? Or settle differently than the other?

And why not just do the entire bottom cement if I shouldn't mix the types.... I am good at cement... Not sure about the pool krete.... Also... Would this hurt... If I chose to do cement could I seal the cement? I have left over sealer from when I built my house and stained my cement.... I can get the cement smooth and add the sealer which would further smooth it out.... But I don't know if it would affect the liner at all... I mean it dries hard and slick so I don't see any problems.... But that's why I'm here!! Again, I'm just throwing ideas out there.... Getting your highly appreciated opinions!

Yes.

If you do concrete, how will you allow for expansion joints?

Although pool krete is actually a brand of material, it's also used like "kleenex" for tissue. It's not really cement as you think. It has portland cement and sand, but it has no aggregate. It also has a bit of vermiculite added as well. Its really more like tile grout than anything. It's also around 500-1000 psi depending on the mix as compared to 3500 for concrete. It will allow water to move thru the material as well, although not as much as pure vermiculite. You dont want to use real concrete like you would use for a slab or walkway. A lot of concrete companies will have the mix as part of what they sell. Vermiculite is mixed up out of bags. As I said earlier, you can DYI it, but a lot of pool DYI'ers sub the floor out.

I wasn't going to... Lol... I don't see the reason for expansion joints?? I mean... I poured my house on a slab, no expansion joints, poured many many slabs with no expansion joints... Including my shop and garage... Again I'm no pro.... But have talked to people that are contractors that never use them and they can't tell me why some people swear by the use of expansion joints.... Again, I'm not trying to make anyone mad... Just learning... So what's the big deal?? Is it the area I'm in? Louisiana... Or is it the people I've talked to that just don't know??

Slabs, decks, walks etc WILL crack. Expansions joint minimize it, but it will happen. You don't want a crack like that in a pool bottom. Thats why, among a myriad other reasons, you want to use verm,iculite or a pool krete mix. It sounds like you definately have your opinions on the subject. You've been given pretty good info and advice. Whether you take the advice or not is up to you.

Ok thanks!! I don't really have my own opinions since I don't do this for a living nor am I a professional... I just have past experience so I'm just learning how to tie that in with new experiences to come!... As far as hiring it out it's pretty much out the question... I dint have the money for it... I gotta do it myself... So that's why I'm here... Getting advice....
So, would the cement cause anything other than cosmetic damages? Would it cause the liner to tear? The reason I ask is the video that comes with the kit...(which I have watched at least 25 times)... Shows the instalers pouring the shallow end in cement when they pour the cement footing around the pool... They have nothing to gain or lose it's just a DVD on how they do it... So I'm just wondering why they would do it like that if it's so bad....

We have been buliding vinyl lined for thirty years our liner manufacturers tell us that the water moves the vinyl and will cause it to get holes with a true concrete bottom