Poured concrete pool leaking

[grywlfbg]

Gunite is also not completely waterproof, I've read a lot of threads here about water leaking from somewhere, so I guess the pool is going to leak if anything goes slightly wrong during construction?

Correct, gunite is NOT waterproof. You HAVE to put something on top of the gunite. @SuzfromTexas listed the most common ones above: plaster, vinyl, fiberglass, or tile.

 

[dw9000]

Have you considered dropping a vinyl liner in it? I think you could get a good concrete coating, painted on,, then tile over that and use a polymer 'water proof' grout. You'd have to either do some research on the best combination of 'coating/paint', tile,, mortar for the tile and grout for between the tiles OR call the pros. I have a concrete pool with a vermucilute floor, I dropped a liner in it = but originally intended to tile the entire inside,, but was too concernted about the concrete cracking over time and therefore cracking the tile,, and having major leaks.

 

[LapPoolMike]

because the pool is partially overground we can see all the hose connections and they don't appear to be the cause. In fact the pool has drained beyond these and continues to drain. There are no obvious wet spots outside.....It could however be the pool drain at the bottom (is there an easy way to test this?)

Regarding plaster - it's difficult to see what an equivalent product in France would be. .....From what I read on French forums, this usually needs to be reapplied every 2/3 years (4 if you're lucky).

Sounds like the agreement was that you would receive a "waterproof" pool, but you have not. It is the contractor's responsibility to determine how the pool is leaking. Sounds like you have ruled out the hose connections (returns) as source of leak, leaving the drain. There are dyes available that can be squirted around the pool shell penetrations (returns, drains, etc.) and then watched to see if the dye escapes with pool water through a leaking area. They may be able to put a plug in the drain, and if the leak stops then you know it must be in the plumbing between the drain and the pump. By the way, there may have been a secondary outlet in the drain that they sometimes leave open while the concrete shell is curing (before pool is filled) to relieve ground water pressure under the shell.....obviously they should install a plug in this outlet properly before the pool is filled, I'd ask about that.

I mentioned my pool finish is Hydrazzo.....Aquavations Hydrazzo combines coarse graded crystalline and colored marble, along with white Portland cement and a host of other performance-enhancing ingredients to create the pool coating. So you can see it is Portland cement based. This type of finish may generally be referred to as "Marcite". If proper pool water chemistry is maintained, I think a finish like Hydrazzo could last 15-20 years or more. I'd try to find a coating that would last longer than 2-4 years if possible.

They have commercial public pools in France, don't they? How are the interiors finished in those?

 

[Pooldesigner1]

Bare concrete is not waterproof. Leaking out "quite substantially" is not through concrete however. While the concrete is porous it would be seeping out. Did they pour the floor first and than walls? Did they use a waterstop at the cold joint? That's a possible leak. Also, any fittings.. main drain, lights, inlets, skimmer etc. A pool finish has to be done. If tiling the entire pool, waterproofing should be applied. Such as thoroseal (spelling?) or Basecrete.