New DIY Vinyl IG Pool Base/Bottom Problems - Please help!!!

Jun 13, 2011
7
Hi everyone. We are doing a DIY 20x40 inground vinyl lined steel wall Grecian pool install. I will post pictures of our step by step progress as we have learned much from looking at others but in the meantime we are in desperate need of advice. For our base/bottom we went with a sand/Portland cement mix with a ratio of 6:1. We have an acquaintance who was previously in the pool business so we hired him to lay the base this past weekend. We did the mixing, had some hired help for transporting the mix into the pool, and he basically layed the whole thing in 14 hours on Sunday – LONG day. While it was wet everything was looking good but the next morning it was obvious we had major problems. We had trowel marks like crazy, rough and uneven areas throughout and large breaks along the bottom of all areas where the wall meets the bottom as well as at the top and bottom of the slope. Unfortunately our guy is only available on weekends and us wanting to get this thing done right and get the liner in, we decided to hire a professional concrete installer to come out and get our surface smooth and ready for the liner install. This time it took 2 guys 7 hours to do. They patched the bad areas and went over the entire surface (except they skipped the bottom of the deep end for some unknown reason). These guys seemed to use more Portland in the mix and went over the surface with a wet sponge after each area. Again, it looked great wet so we paid them but then after everything was dry it still has major issues! Now some of the breaks are filled in but the entire surface is rough and bumpy– somewhat similar to a popcorn ceiling. We also have large areas that are VERY rough and uneven. Along the edges of the shallow end (the only surface that was actually good after the initial install) they failed to go all the way to the edge so we have 1/8” ridges in many areas. They also rounded out one of the corners of our deep end so we now have one corner of our Grecian pool that is essentially round. It is very frustrating to have paid to have this done twice and still not have a usable surface. Perhaps we are looking for too much but our research indicates that the base should be a smooth surface. Any advice on how to correct this would be greatly appreciated!!!!
 

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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Here are some of the pics from after the second go at a base... I have more if anyone needs to see more detail
 

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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Here are a couple pics of the before and after of the Grecian corners in the pool wall... Notice they start with nice lines and after the 2nd concrete crew they are now rounded!
 

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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Good evening! You need to wet it down again and smooth out all the rough areas. It will show up plain as day when you turn on the light for the first time. Also make sure that you scrape the steel walls prior to installing the liner and make sure there is no concrete splattered on the walls. You might want to use wall foam. Where are you located?
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

It was in the upper 90's today and the bottom is pretty solid. I'm not sure that it will soften up to trowel out. We will be using wall foam and cleaning the walls prior....Pool is in Mid GA.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Welcome to TFP!!

Sorry you have this problem! :rant:

You did the obvious thing in hiring "pros" - unfortunately, you didn't get pros :(

Unless your troweling skills are better than theirs, you need to hire some real pros or do it yourself :evil: This is something you'll have to live with for the duration of your liner, so it's best to have the floor 'right' before the liner goes in.

Where are you located?
 
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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

We are in Warner Robins GA.

The biggest problem we are seeing at this point is the guys went over the bottom with a large sponge. This looked ok when wet but when I got home from work I could see the ridges from the sponge. It appears that the sponge was clogged with sand/portland and left ridges in the bottom.

Would it be ok to smooth these ridges down with a scraper or a stone???? vs relaying the bottom?

or is that just bad practice.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

It needs to be skim-coated again. You will be highly disappointed if you fill it up as-is. Everything will show up when your light is turned on.

We arent too far apart! We did a pool in Warner Robins last year.



ps. your light panel appears to be upside down.
 
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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

One more thing that can be a major headache. The main drain screw holes are not protected. They should have been taped over so sand and portland doesnt get into them. Make sure that before the liner goes in, that the screws will go in all the way without getting stuck. If the screws wont tighten, then the liner has to come out again.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

That is funny you mention the light panel. We actually originally had it the other way but weren't sure so we contacted the pool company (National Pool Wholesalers) and they told us the light should be at the top so we flipped it over. Oh well too late now I guess. We really didn't give that much thought after they told us that as we had a major issue at that point as well. We had assembled the steel walls, leveled and squared everything but were noticing that despite being square, our pool dimensions were coming up like 6-8" longer than they should have. We couldn't figure it out and the pool co lines were down so we contacted the liner manufacturer to see if that was normal and if the liner would really strectch that much. They went over everything with us and helped us find the problem - the pool company sent us "W" filler for the grecian corners instead of "V" filler. The "W" filler corners are a much larger piece and add to the dimensions of the pool instead of just fitting in the corner. Having never done a pool before and given that everything fit and looked right, we had no clue. After two days on the phone with the pool co insisting the overnight us the correct "V" fillers, we got to take it all apart and put it back together again. What fun! At that point it seemed miserable but looking back now I would redo that 3 more times versus having this bottom issue.

Speaking of the bottom - if we have to re-skim the entire thing, would it be better to use vermiculite this time? We are having doubts if we will ever be able to get a smooth finish from the portland & sand. Can vermiculite be used over the existing?

Thanks for the tip about the main drain screws too- will check those tomorrow for sure.
 

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Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Crew I used to work for used a portland/sand/vermic mix. Any imperfections in the initial troweling could easily be knocked down with a few scrapes of the finishing trowel and for minor dips, a portland paste applied. We used to use dry grout ( what you have applied) when we were building pools without a shell and against virgin dirt. Depending on how your mix has set up, you may actually be able to scrape off the ridges and fill depressions with the same 1:6 mix. This doesn't mean you have to do the entire bottom. Just the areas that you deem need it. It's not going anywhere. Your pool will be holding that patch in place when it's filled. No need to worry about it moving or collapsing if it's applied properly. Feather it out and it won't show either. That said...you will never get an absolute perfect bottom. Just doesn't happen. What is noticeable are ridges. Minor depressions (1/4 inch) don't show but may be felt with the feet. Right now, your concern isn't getting that bottom up to snuff unless you're ready to drop the liner. It's completing everything else ( deck, plumbing, equipment pad/equipment).
I see you have added to your question. Yes, you can vermic what you have but you'll need to do it all. The advantage to it would actually be a softer feeling bottom and it is easier to knock down ridges but not so easy to fill minor depressions since it's a little more difficult to feather out.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

Thanks scubaguy - interesting things to consider. This is our last step before liner drop. Plumbing, electric, collar, backfill, and deck are all done. I will work on getting our step by step pics up tomorrow
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

I used a sand/cement mixture for the bottom of my pool a few weeks ago. In the end the finish was good but not great. There were hairline cracks in a few places. My solution was to skim coat the entire surface with thinset (typically used for setting tile) then smooth with sandpaper to hit the ridges (small orbital sander - took about an hour). Used about 4 large bags of the cheap stuff. I think it came out very well and it even looks good with the pool light on. As a bonus the thinset is not as abrasive on the liner as the sand-cement is. Hadn't heard of anyone else doing this, but it seems to have worked for me.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

jguy said:
I used a sand/cement mixture for the bottom of my pool a few weeks ago. In the end the finish was good but not great. There were hairline cracks in a few places. My solution was to skim coat the entire surface with thinset (typically used for setting tile) then smooth with sandpaper to hit the ridges (small orbital sander - took about an hour). Used about 4 large bags of the cheap stuff. I think it came out very well and it even looks good with the pool light on. As a bonus the thinset is not as abrasive on the liner as the sand-cement is. Hadn't heard of anyone else doing this, but it seems to have worked for me.
Hairline cracks are something you don't need to concern over. It happens during the cure. Anything you can slip a matchbook cover into or larger are issues and ought to be addressed, sure.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

bullet225ho said:
Thanks scubaguy - interesting things to consider. This is our last step before liner drop. Plumbing, electric, collar, backfill, and deck are all done. I will work on getting our step by step pics up tomorrow

One thing you need to be thinking about is your liner. I gather you built the pool to spec and that the liner is already made? If so...these bottoms are reducing your wall height. Bear that in mind and what the liner wall height was built to. It doesn't fit like a glove...it's supposed to be built smaller than your actual pool, other than the perimeter. It's meant to stretch into place. No place to stretch to and you may get a wrinkle or several.
On the other hand, if the pool wasn't built to a liner spec and you are getting someone in to measure it out for build, not much to worry about after your final bottom is complete. It'll fit fine since they build in the stretch factor in their measurements of the final shell.
If you do decide to vermic..don't go thick. No need to. 1/2 inch is all and thinner where you can get away with it in areas like the shallow end or wall slope tops.
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

If you go with Vermiculite, Sunland Pools sold it to me for 12 a bag. I was able to pick it up in Decator, GA rather than having it shipped. Im sorry for what your going through. I can relate because I did my bottom myself and it didnt come out as nice as I thought. It looked good when it was wet but then it dried and was rough looking. lumpy and bumpy lol! I got my orbital sander and worked with 60 grit sandpaper for hours. I then did a whole LOT of patching again. It looks terrible. I just dropped my liner yesterday and it looks great in the daytime but im sure this will change when the lights come on. I think the only solution is patching and sanding. Too many coats will bring your floor higher and your liner wont fit. Make sure you sweep it good- i had to climb under my liner a few times because of small rocks- its hard to breath under there lol
 
Re: New DIY Vinyl IG Pool Base/Bottom Problems - Please help

When we replaced our in ground liner last year, I patched with sand/cement and used a pool pad to cover the entire bottom. This worked out great. You may want to try it. I like the thin set idea - wish I had thought of that!
 
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