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A few questions for those who design concrete pools.

[Subject Prev][Subject Next][Thread Prev][Thread Next] I know I have asked a few of these questions before, but I need to get a couple of opinions since I have had some conflicting responses. The questions have to do with the installation of Gunnite and the standards used.

1. Does the Uniform Building Code (or 2000 IBC) make any specific reference to the structural design of Gunnite Pools?
2. While it may be sound practice to follow a concrete building standard for the clearance of reinforcing steel from earth and air, are there any specific standards of practice or published codes that mandate the placement and minimum clearance of steel in a swimming pool?
3. It is my understanding that the finish on most Gunnite Pools is considered a structural plaster used to provide a smooth surface. It is also my understanding that the plaster used is, essentially, concrete and can obtain the same strength as the concrete wall below. Is this valid?
4. It is my belief that all concrete (including Gunnite) cracks. The crack needs to be evaluated to prove if it is caused by defect or by normal processes such as temperature cracking (hairline). I also understand that most cracks will not cause sufficient leakage in a pool as the wetting of the concrete surface would tend to swell the concrete and essentially seal the crack. Is this a valid assumption for temperature and hairline cracks?
5. I've been told that the plaster finish on a pool is a waterproofing finish. Is this considered a valid assumption by most of you?
6. There are a few contractors in the area who specialize in the repair of Gunnite pools who rough up the surface of a pool considered to be a thin wall shell and who add an additional 4-inch shell of Gunnite within. There are alternatives that I believe are less costly - pool liners, Epoxy-injection and new plaster finishes etc. What alternatives have you used to repair minor cracks (no elevation changes and no cracks larger than approximately 1/32" in width) in a Gunnite Pools
7. Final questions: Is the City Inspector required to inspect the placement of the rebar cage before the Gunnite is shot on. If so, is the cage generally set on chairs to hold it away from the earth to allow for clearance between the earth and rebar (assuming that some standard or minimum clearance was originally specified by the design engineer)?

If you prefer, please feel free to email me privately with your response. If others want to know what the comments were, I'll be happy to post them on the Structuralist.Net or if you prefer, leave them on the SEAINT list.

Thanks in advance for those of you who respond.

Dennis S. Wish, PE
Structural Engineering Consultant
structures(--nospam--at)engineer.com
760.564.0884 - Phone
208.361.5447 - Efax