Cove Sand Washout

[Mr. Fixer]

Hello All,

My above ground, oval, pool was installed last spring. We had a lot of rain last year and by the end of the summer I discovered a washed out section of cove sand at the transition of the straight side to the radius. It's about 3"-4" long and maybe 1-1/2" deep. (at the end of last season) The liner is bulging into the void. Regardless of the amount of rain I don't think there should be any washout of the base. There are multiple minor, divots or voids along the bottom. These smaller spots at the bottom aren't a real concern to me, but they do lead be to suspect the installers prep of the base and cove. I haven't been able to figure out a way to fill the void. My friend had a similar situation and eventually the bulge ruptured. He's now looking at a liner replacement this coming season. Does anyone know of a solution for this or do I just cross my fingers and wait for the impending leak?

 

[Texas Splash]

I'm assuming there is no applicable warranty at this point huh? At least nothing that applies to the wrath of Mother Nature? I would think that the sooner you can fill those voids, especially the larger one along the side allowing the shell to bulge outward, would be a priority. I'm not familiar with IL standards, so hopefully someone else from your area will have some thoughts. All that comes to mind for me is fine pea gravel and/or sand, but I'm in TX. We throw anything into a hole and call it good.

If you can save it, you might see if it's worth installing something like a French drain around that area as well to help divert heavy water flow. Hopefully you'll get more replies soon. Best of luck to you!

 

[kimkats]

The only thing you can really do is remove the water and replace the cove. I suggest you add more sand AND use the foam cove as seen here: Peel and Stick Pool Cove (48 inch) - NL102 - INYOPools.com

If you wait for it to let go it could be a lot harder to fix as it will take more sand with it AND it could damage the walls and wall tracks.

Once you do that think about how the rain water flowed and see what you can do to keep it from going to that area.

Good luck I know it is not a fun thought but better safe than sorry. When our pool bottom went out the force of the water almost took me with it. If I had not been able to grab the deck and jump out I would have been hurt. Scary stuff!

Kim

 

[CJadamec]

Is it just a divot in the cove or is the cove totally gone?

If the liner is pushing all the way down to the base of the wall you should drain the pool and fix the cove asap you really don't want the liner to get under the wall and burst.

I had a divot like you are describing show up at the beginning of last summer and I was able to basically push the sand under the liner into the low in the coving. I did it a little bit at a time slowly working the sand from farther away towards the divot with my feet. After a couple of weeks it was mostly smoothed out. I checked it frequently all of last season and it never came back. I will be back in my pool in a bout a month or so to inspect the base and see how it handled the winter. Everything froze up really solid this year for about a month easily the most ice I've had since the pool has been up.

 

[CJadamec]

There are a lot of rodents that can dig tunnels under a pool and cause what look like washouts as well.

Banking sand topped with crushed stone to mimic the coving on the inside of the pool on the outside of the pool can be a good defense against ground water washouts as well if it looks like that is the cause of the problem.

 

[IrishEyesSmiling]

We had/have the same issue of cove washout after install last year. I never thought to push sand with my feet because I didn't want to touch the area any more than necessary. So far we've had no water loss or issues even with running the robot everyday last summer. We have a gorilla pad down now but when we replace the liner I plan to go the extra mile with wall covering and foam cove. For now I'm keeping my fingers crossed it won't bust. I wish you the same luck (and hope I didn't just jinx myself)!

 

[DaneCE]

Hopefully you don't have other locations developing the same problems. If the damage remains contained to the one spot you might consider gluing a clear patch over it to reinforce the liner. Last Spring I realized I was losing water and discovered approx. 20 pin holes at the base (cove) of my 6 year-old liner. The sand cove almost completely collapsed over 100% of the perimeter on my 15 x 30.The liner simply stretched too much at the cove area. I spent over 3 hours patching just to get through the Summer. I'm currently working on a total renovation, using 1" EPS over the sand with foam cove using a few extra tweaks for complete overkill.

 

[Mr. Fixer]

Sorry for the delayed response. Life keeps getting in the way of my fun. Thank you all for your input and advise! I think my problem is critters. Voles? My dogs bring them home now and then. I stared draining the pool last night. I'm down to about a foot of water. I plan to take the water level down to the point (2"-3") were I
can pull back the liner in that area and back-fill the hole. Thoughts?

Thanks again all!

 

[kimkats]

Slow and careful......will you add the dirt from the inside or outside? We had a washout when our flex hose came off and wash some dirt out. I was able to dig under the bottom track and push the sand back in. My husband was on the inside and used his foot to "make it pretty" as I pushed it in. It was NOT fun for me but it worked. We now have hard PVC plumbing AND large pavers under the return and skimmer for just in case something happens again.

Kim

 

[Mr. Fixer]

Adding sand from the inside.

 

[kimkats]

Make sure you have a good way to keep the liner from coming out more than you want it to. Work slow and careful. Add, pat, Add, pat, etc.

 

[karwhite]

Slow and careful......will you add the dirt from the inside or outside? We had a washout when our flex hose came off and wash some dirt out. I was able to dig under the bottom track and push the sand back in. My husband was on the inside and used his foot to "make it pretty" as I pushed it in. It was NOT fun for me but it worked. We now have hard PVC plumbing AND large pavers under the return and skimmer for just in case something happens again.

Kim

So I am considering doing this it is just a small area that has a divot in the cove but liner is fine no leaks yet and my yard is very sandy because i live near the beach. did you secure the outside after you pushed the sand back in I am thinking maybe packing in some good top soil and then putting down paving bricks after.

 

[kimkats]

Use ONLY your hands with NO long nails! My husband was on the inside and helped "mold the sand I pushed in so it would not bunch up all in one spot. He packed it down with his feet. It not fun but worth it as you could not tell when we were done.

What we did after that was dig down a bit on the outside all under the skimmer and return area. We put small, rounded rocks all in that area. We then put pavers there and sloped them a tiny bit so any water that came out of the area would hit the pavers and go away from the pool. This was also helpful when we had big rains.