Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Erosion around concrete slab

  1. Back To Top    #1

    Join Date
    Jun 2014
    Location
    Houston, Texas
    Posts
    3

    Erosion around concrete slab

    I have recently acquired a leak in an underground PVC pipe, which is under the concrete slab for my underground pool. While digging to find the leak I observed that there were serious erosion issues underneath the slab (4-6 inches average). At first I thought that this was due to the leaking pipe, as I'm losing a lot of water when the pool pump is running. After having dug around the edge of the slab I observed that whoever built the pool never connected the pool overflow drain into the drain pipe. There's about a 4 inch gap between the two, and no evidence of a broken pipe, glue or sealant on either ends of the pipes, or other missing connections to indicate that the two pipes ever were connected. This leads me to believe that the erosion has been ongoing since the first day the pool was filled. As I am at least the third owner since the pool was installed, I have no way of finding out who built it and the pool is out of warranty anyway.

    Once I fix the leaking pipe and the missing drain section (both under the slab, but it's only 4-5 feet wide at that point, so I'm going to try to fix them without breaking up the slab) I need to shore up the concrete so it doesn't crack. I'm surprised that there have been no issues with it so far, considering how bad the erosion is. My original plan was to bring dirt in and fill in the washed out areas, but now that I've got 40 feet of slab dug out it's probably not going to be possible to fill in around the entire pool with dirt. I'm not even sure how far around the slab the erosion goes, but I'm going to presume a worst case scenario. I'm thinking about placing concrete cinder blocks under the slab to support it, possibly every 10 feet or so. I may need to place some as far under the slab to help support the slab in varying places, and also some on the edge of the slab, but at one point the slab is 30 or so feet wide, and I won't be able to get very far underneath it at that point.

    If anyone has some suggestions on how to shore up the slab safely I am all ears. As I just had to buy a new pool filter and a new refrigerator hiring someone to do it is not an option. This will be a DIY and it's definitely not my strong suit. Thank you all for your time in advance.

    Paul
    15,000 Gallon pool
    2" piping
    Pentair 2 HP pool pump

  2. Back To Top    #2

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,435

    Re: Erosion around concrete slab

    Can you post a picture of what you are seeing? Slab, erosion, etc.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

  3. Back To Top    #3

    Join Date
    Jun 2014
    Location
    Houston, Texas
    Posts
    3

    Re: Erosion around concrete slab

    I have attempted to attach pictures of the problem, but the website would not let me. Below I have inserted links to photobucket. If they don't work let me know and I'll try something else. One picture shows the amount of slab I've excavated. So far everywhere has had the same erosion problem. From the outer edge of the slab all the way to the wall of the pool is eroded. The other two pictures (one taken badly) show the erosion between the bottom of the slab and the ground. There is about a 6" gap between the two. I need to find a way to shore up the slab.

    http://i1378.photobucket.com/albums/...ps8ededcd1.jpg

    http://i1378.photobucket.com/albums/...psd7a810d4.jpg

    http://i1378.photobucket.com/albums/...ps1ef8281b.jpg
    15,000 Gallon pool
    2" piping
    Pentair 2 HP pool pump

  4. Back To Top    #4

    Join Date
    Jul 2014
    Location
    Shawnee/KS
    Posts
    15

    Re: Erosion around concrete slab

    May want to check with local concrete companies. Not sure if mudjacking would work for this or not to fill the voids under the slab.
    IG 21,600 vinyl gal 38'x20' 3.5'/8', Pentair Sand Dollar SD80 filter, Pentair 1.5HP pump, Auto Pilot Salt Chlorine Generator RC 28. 2 LED lights, 2 bubblers.

  5. Back To Top    #5

    Join Date
    Apr 2013
    Location
    Sacramento, CA
    Posts
    2,769

    Re: Erosion around concrete slab

    I'm not sure but I think I see Jimmy Hoffa's body in that second picture.

    Mudjacking or slury might work. I agree with Sierra call several local concrete contractors and see what they say. Get some bids.

    I'm concerned that the concrete block idea may just make it worse over time. I suspect that this is only doing so well because of rebar in the slab. Concentrating the force on blocks may just cause more problems.
    22k gallon IG pebblefina, Jandy 1.5 HP VS, Jandy CV Cartridge filter, Fafco solar panels, Polaris 360 supply side cleaner, waterfall

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •