Crack in fibreglass pool

Jump to latest Follow Reply
T

troubleinpooladise

New member
Jul 20, 2022
4
australia nsw
Hi all,

Last week our backyard and pool area flooded and after this I noticed about a 10 inch crack running along the floor from the wall. The floor appears raised maybe an inch around the crack.

Is there any fibreglass pool experts here able to weigh in on what caused this crack in my pool and if it may be repairable? I was thinking maybe hydrostatic pressure but the rest of the pool looks fine and the crack seems in such an odd location. We do have clay in our soil so it might be reactive.

I am now losing about an inch of water every day. Any suggestions would be appreciated.
 

Attachments

  • 20220720_150555.jpg
    20220720_150555.jpg
    288.3 KB · Views: 35
  • 20220720_150626.jpg
    20220720_150626.jpg
    201.8 KB · Views: 35
  • 20220720_150617.jpg
    20220720_150617.jpg
    282.7 KB · Views: 34
Last edited:
Welcome to TFP! :wave: That is an odd location. Almost like something isolated (rock, roots, etc) raised enough to cause that crack. Almost sure that's the source of your water loss. Squirting a little food coloring around that crack should confirm. A repair would probably require lowering the water level almost to empty which of course is an ordeal in and of itself with FG pools to brace it and try to prevent popping. But that doesn't address the true cause of the problem - what's underneath? Difficult situation I'm afraid. I would reach out to some local pros to see how they feel about it.
 
Thanks Splash! And thank you for your response.

I went into the pool today to put some putty in the crack to stop the leak and... it was like I was standing on a bouncy castle!! The steps and the walls are still solid but there is a big area in the middle of the pool that just seems to be floating. I'm guessing that my hydrostatic valve failed and there is water pushing up the pool from underneath? And the crack must be where it gave in to the pressure.

Does anyone know if I can get the crack repaired and the pool may be able to survive? I'm worried that I may need to get the whole pool resurfaced or the backfill replaced. I'm guessing there may be sand underneath the pool which has liquefied? So many questions. Should I get the hydrostatic valve replaced asap? Should I try to pump out the groundwater through the standpipe?

Any suggestions would be appreciated, I can't really afford a big repair bill at the moment so hoping I can get by somehow!
 
You're going to want to pump out the groundwater as to not have any more damage occur. Do you periodically check your sump pit area for groundwater? If not then moving forward I suggest you do. I'll let others speak to what to do with shell and backfill but I'm guessing the crack would be repairable and nothing can be done about backfill without pool removal.
 
Definitely several "unknowns" underneath. Unfortunately the only way to know for sure may be to lift the shell unless there is a company with some high-tech equipment that can scan the material underneath (i.e. sonar or something). If the HSV did fail, it certainly should be replaced. You mentioned pumping-out water form a standpipe? If you can, I would do it. For the repair, the pool may need to be emptied. To to that requires the pros to secure the pool from additional movement and perhaps drill some relief holes at the bottom which in your situation may be a good thing. Maybe a contractor can find a way to provide structural support below with some of today's high-tech materials like the expandable foam used to level driveways and such to stabilize the shell? Not my area of expertise, but just tossing some ideas and optimism your way. Keep us posted on this journey. Wishing you the best.
 
Well, time for an update! If anyone else has a similar problem, maybe this will help you.

I'm still not entirely sure of the cause, but I put it down to a combination of hydrostatic pressure, reactive clay soil, and improper backfill (sand).

What actually happened is the pool was pushed upwards a little bit, causing the bottom to bulge up and the crack to appear in the weakest spot.

The way to repair is to brace and drain the pool, pump out excess groundwater, cut open the entire bottom lengthways, cut off the excess fiberglass to release the tension, and then apply new fiberglass to stitch it back together. I then applied epoxy pool paint to protect the new fiberglass, new hydrostatic valve, and job done.
I still need to resurface the entire pool in future as there is some osmosis starting to appear, however the pool is now repaired and leak free!

I couldn't afford any contractors that I quoted to do the job as they were only interested to do a complete resurface for which they charge an arm and leg, so I decided to get by this way with some help and advice from others. Its a labour intensive job, but quite doable!


20221015_085653.jpg20221220_185246.jpg
 
Last edited by a moderator:
Wow. What a chore. I too discovered a small leak at a return jet, tucked-up in the threads at the 12 O'clock position. Very hard to find. I've remedied it for now and hope it didn't disturb my sand base below too badly. Good to see your pool full again. :goodjob:
 
  • Like
Reactions: troubleinpooladise
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply