Above Ground Pool Wall Failure

[Steve Frederickson]

Does anyone know of any good reference material on pool failures? I've been searching teh internet with little luck. I'm inspecting a couple of pools for an insurance company. They're both above ground, round pools, approximately 24' in diameter. The homeowners are clamiing that the pools failed due to the weight of ice/snow (a covered loss) vs. normal aging (which isn't covered).

In both cases the rivets where two wall panels meet popped, opening the pool like a zipper. I didn't see any sign of corrosion. It seems to me that a few feet of snow/ice on top of the cover could overstress the tension tie, which was probably designed for only the weight of the water in the pool plus some factor of safety. The pools are both located in New Hampshire, which had a particularly tough winter this year (many roof collapses).

I'm interested in design information that would offer me some insight as to the design of the tension ties and what kind of weight on the cover they can normally hold. Any informatin on failures of this type would also be appreciated. Attached are photos of one of the pools.

[James Duffin]

It appears that the pools was not winterized properly. I suggest that you get hold of an owners manual and see what the manufacture says about winterizing the pool. If it was not done properly then the insurance company should be off the hook.

[Paul Kondzich]

Were the pools filled with water when they failed?

[Rick Hurst]

That pool looks like it may be a DOUGHBOY brand pool. They are one of the leading companies in the above ground pool business.

Doughboy Pools (http://www.doughboy-pools.com/?page=0)

We had one at our first house years ago the same size (24ft. round). We were advised to drain the pool down below the skimmer in freezing weather but we never had that worry at the time.

I've never seen one collapse as that pictured. It may be possible that the pool was allowed to be over filled with water which the water pressure could have led to the wall collapsing.

I'd contact the above company DOUGHBOY and maybe ask them about such an issue.

Good Luck.

rick

[Jerry Peck]

The homeowners are clamiing that the pools failed due to the weight of ice/snow (a covered loss) vs. normal aging (which isn't covered).


I can't understand the "failed due to the weight of ice/snow" part as both ice and snow weigh less than water.

If it is rated to hold water, it surely should hold ice/snow.

The only complication I can see there is if the ice were to be thick enough to be massive enough that expansion pushed against the walls sufficiently to shear the rivets.

In that case, I would suspect that it was "operator error".

[Joe Klampfer]

I'm guessing the next problem those poor people will be facing might be deck failure. Looking at the way it built, I'm surprised it didn't co lapse during one of their pool parties long before the pool itself :)

[Jerry Peck]

It also did not have a proper child resistant fence/enclosure around it, not even being an above ground pool.

[Steve Frederickson]

My thoughts regarding the weight of ice and snow are: if the pool is designed to retain 4' - 5' of water, and there is a cover on the pool with an additional 4'-5' of snow on the cover, the weight of the snow would increase the pressure on the side walls of the pool and possibly cause the wall to fail. I was hoping that there were some pool experts out there who might be able to offer some insight.

I've done some research into recommendations from pools manufacturers regarding winterizing, and I can't find any that say to remove the snow from teh cover. In fact, some say not to remove the snow because you can damage the cover. But, isn't there a point where the weight of the snow on tiop of the cover could overstress the wall?

Regarding the fence, I wasn't there to do a code review or home inspection. I was just there to try to determine the cause of the pool failure. At the risk of changing the direction of this post, as I recall there was a guardrail preventing someone from getting onto the deck and into the pool. The door from the house to the pool might have been alarmed, but probably not.

[Rick Sabatino]

I had above ground pools growing up. We had to drain them about a 1/3 and always had a large (8'sq) inflatable pillow or bag placed under the cover to absorb the pressure when the water froze.
My bet is that the pools were not properly winterized.

[Rick Hurst]

I had above ground pools growing up. We had to drain them about a 1/3 and always had a large (8'sq) inflatable pillow or bag placed under the cover to absorb the pressure when the water froze.
My bet is that the pools were not properly winterized.

Rick,

Now that you mention the inflatible, we did have one of those. You are correct in that the installer told us to put it in the pool if freezing weather was approaching. It was intended to keep the water from freezing solid across the top of the pool.

The other rick

[Kat Sanford]

I would agree with rick, from my past experiences it definitely sounds like your pool was not correctly winterized. A friend of mine had the exact same issue and I'm glad I learned from her when installing my own above ground pool (http://www.kayakpoolsmidwest.com/). I made sure that it was properly winterized so I would not have the same issue. I would check your warranty to make sure this problem will be covered so the repairs won't come out of your pocket.

[David J. Smith]

Proper winterization is not always the cause. I had a brand new pool spring a leak in the spring when the ice was still in the pool. The water leaked out and the remaining big chuck of ice tipped over crushing the sides of the pool, which seems to be what I see in one pic. The pool was replaced on the warrenty. Two winters ago we had record snow falls and there were many pool failures. The weight of the snow on my winter cover twisted the top supports somewhat. The extra weight of snow and ice on pool covers could cause damage.

[Scott Phillips]

Rivets or stainless bolts joining steel wall?

[Scott Phillips]

What are ages of the pools? Do they have any corrosion? As other poster asked, how much ice and snow on top? Small leaks in liner that would not be noticed could have weakened the walls.

[Paul Johnston]

It appears that the pools was not winterized properly. I suggest that you get hold of an owners manual and see what the manufacture says about winterizing the pool. If it was not done properly then the insurance company should be off the hook.
My guess would be they did not 1. drain the pool below the shimmer and 2. did not put a inter-tube or blow up pillow under the cover for the water to climb when it freezes. Look at the liner for water stains around the skimmer to see how full it was. Lots of people put off winterizing until it is too late.

[Patrick McCaffery]

Hi Steve,
As you are looking for failure data for swimming pool failure, I would suggest looking to insurance companies. They should have a history of the failures and previous investigations in regards to this type of failure. The National Safety Council might be another area. The Safety Department in the particular state, may also have information. Some of the information you should be looking for are; how many pulls failed during this particular winter, how many were the same manufacture and how many had the same design.

[Bob Barnett]

It appears that the pools was not winterized properly. I suggest that you get hold of an owners manual and see what the manufacture says about winterizing the pool. If it was not done properly then the insurance company should be off the hook.
I have a pool similar and have leaned that if it does overfill during the colder months, they make a drain, that I use to remove excess water during partial thaws, or from the pool itself to maintain a certain level. But usually a properly winterized pool should not do that IMO. And beleive me We had a rough winter last year.

[Roger Frazee]

Found this on a google search

Above Ground Pool Ice Damage (http://saratogadeckpool.com/icedam.htm)

[Jess Moznot]

Another caveat may be whether the pools was properly winterized. Many pool owners don't take the time to properly winterize their pools or they don't follow the correct procedure in spa filters (http://www.familyleisure.com/Pool-Spa-Filter-Cartridges/) upkeep, which over time can cause the aging of the pool to speed up. Here is a great link on proper winterization technique.

How Do I Winterize a Swimming Pool? (http://www.wisegeek.com/how-do-i-winterize-a-swimming-pool.htm)