How to renovate a cracked concrete swimming pool?

[Avsvs]

Hi everyone,

I’m hoping to get some advice on the best way to fix my pool.

We moved into our home about 20 years ago, and I was told the pool is made of Besser blocks with concrete and some fiberglass patches, which were then painted over.

Unfortunately, it hasn’t been repainted in a long time, and when I recently drained it to prep for either - repainting, adding a vinyl liner, or tiling, I discovered a large crack at the bottom.

I plan to do a lot of the prep work myself—sandblasting the sides, grinding if needed, and making sure everything is smooth and ready.

As a single mum on a mortgage with a limited budget, I’d love to hear your recommendations on the best, most cost-effective way to repair the pool, 

so, it looks good and stays functional. Any advice would be greatly appreciated!

Thanks in advance! 

 

  

 

[Avsvs]

Hi Dave,

Unfortunately i can not afford to get an engineer out - just isn't an option, however this is what i have found 

• High-pressure injection of epoxy or polyurethane resins is used to repair deep cracks in concrete. Polyurethane is typically used for active or live cracks, while epoxy is preferred for dormant cracks or when structural integrity is the primary concern. Polyurethane, with its expanding properties, excels in sealing wet and moving cracks, whereas epoxy offers high strength and permanence when structural integrity is crucial. 
• Epoxy Injection:
  • Application:

    Suitable for dry, dormant cracks or where structural repair and strength are paramount. 
  • Mechanism:

    A low-viscosity epoxy resin is injected under pressure to fill the crack, restoring structural integrity and reducing water penetration. 
  • Pressure:

    Typically performed at lower injection pressures (20-200 psi). 
  • Limitations:

    May not be suitable for active cracks or when future movement is anticipated. 
  Polyurethane Injection:
  • Application:

    Ideal for wet, leaking cracks and cracks subject to movement. 
  • Mechanism:

    A water-reactive polyurethane resin is injected under pressure. The resin expands upon contact with water, sealing the crack and preventing further leakage. 
  • Pressure:

    Often performed at higher pressures to ensure the expanding foam fills the entire crack. 
  • Advantages:

    Flexible and durable, can adapt to crack movement, and is suitable for various crack widths. 
  Choosing between Epoxy and Polyurethane:
  The choice depends on the nature of the crack, the presence of water, and the desired outcome. 
  • Structural Repair:

    Epoxy is preferred for cracks that compromise the structural integrity of the concrete. 
  • Water Leakage:

    Polyurethane is excellent for sealing wet and leaking cracks, as it reacts with water to form a watertight seal. 
  • Cracks Subject to Movement:

    Polyurethane's flexibility makes it suitable for cracks that may experience movement. 

[Dave-1]

Afternoon @Avsvs 

I feel your pain, really do (My old school fibreglass pool has a cracked cowl and other things associated with age) and I will be in that same problem area one day as well.

So lets narrow the issue down, Cant afford an Engineer (neither could I short term) tick

Willing to give it a go, tick

Have researched potential ways to fill the crack, tick

Use a paint sealer once crack is filled, kinda tick

Fill with water and see, waiting for that tick.

Two things come to mind as I go through the steps.

1 - Low side of your pool structure, if it fails where will the water go and what damage could it do? My pool is a 45,000L pool and I often think about "what ifs"

2 - Using a rubber liner for the pool itself. So crack is fixed/filled with something flexible enough to last a few years. And then a rubber liner much like an above ground pool is used instead of a painted surface so other cracks may be less of an issue.

I take small steps to solve big problems, its scary spending $$$$ on a repair that may not work but if you havenothing to loose I would say why not. (apart from physical danger of where that water may end up of course and oif you were in the pool at that point of time and failure) Kinda have to say that as it would be remiss of me not not just in case

Looking forward to seeing your steps

Dave

[MitchellMc]

Hi @Avsvs,

With structural cracks to this degree, I think you'll find that most pool restoration experts would determine that the base is unstable and the shell is too damaged to repair. They'd want to remove it and start from scratch. These aren't fine cracks, they are structural and show that the shell is essentially falling apart due to the ground moving beneath it. They might perform a repair and fill the cracks, but it would likely not come with a warranty.

Wanting to do the work is admirable, but I just wanted to point out that it's so damaged you'd likely find it difficult to even enlist the services of a professional to repair it. I have a much finer single crack in the bottom of my pool, and even that has been deemed as non-repairable.

Have you considered the prospect of filling the pool in? That obviously might not suit you, but for me it would certainly be an option. Mine is currently unusable and taking up a large portion of the yard, which my children use to play in.

If you still want to go ahead, then I would suggest getting some quotes on the repair. Even if you don't go ahead with them, they'd give you a good idea of what needs to be done in order to stabilise the moving shell and repair the damage to it.

Mitchell

[Dave-1]

Afternoon @Avsvs 

As a side note, I have often wondered what to do with an empty pool, With yours the sides seem stable (not wanting to falling inwards) Mine is a fibreglass pool so if I empty it, the sides will collapse inwards most likely.

The hole in the ground is a perfect cooler area, especially with a roof covering of some kind. maybe convert your pool shell to something like a sunken gazebo until you decide what you can do? A few short posts along the edge of the pool, a couple of wires and you could string up a shade sail that you could retract? Gives you something to have while you sort out the issue.

Dave

[Avsvs]

Hi Dave and everyone,

I’m not sure how to reply to all, so I hope this reaches the right people.

I just remembered that my brother in Melbourne is a structural engineer. I’ve sent him some photos, and he will most likely fly over to take a look in person.

I also work at Modbury Hospital with the team managing the current new builds. I’ve been asking the builders lots of questions—probably driving them crazy! They’ve even started asking their own contacts for advice, so I’m confident we’ll find a good solution.

I’ll put together a list of different repair options I’ve researched and share it soon so we can see what the general consensus is.

[Dave-1]

Afternoon @Avsvs 

I think thats the way we all learn, I always figure "there is no harm asking" as even a non positive answer still leads teh way forwatrd

Definently handy having family you can hit up  

My back up crew is the workshop crew where I work and also the IT crew for IT related questions

Looking forward to hearing ideas.

Dave