Simbilis
08-18-2010, 06:48 PM
I've been reading up on inground steel and polymer wall pools here (and wherever else Google takes me). There are lots of things I haven't quite wrapped my head around yet, but these few stick out.
1. Where I am in northern VT, the soil is very sandy. The builders I've contacted have all recommended backfilling around the pool with excavated sand. One told me that he'd had a local engineering firm do a compaction test and got compaction of better than 100%. Since 95% is all that's required, and sand backfill is the general practice here, am I likely to get any significant benefit by insisting on gravel?
2. It's been dry recently, but we've had very wet years where the water table was well above where the bottom of the pool will be. Is it enough to put a pea gravel pit with a foot valve and drain pipe below the deep end so I can pump it out, or are french drains also necessary? How much do I need to worry about keeping ground water away from the wall panels?
3. None of the kits I've found for 20x40 rectangular (~33,000 gal.) pools show looped returns in their installation instructions. In fact, they often have only two returns in the kit. How many returns and skimmers are best for a rectangular pool that size, and are looped returns always a good idea? I'd like to be able to turn the water over in 6 hrs, which comes in at about 92 gpm. Three 1.5" returns fed by a 2.5" pipe should be able to handle that with max. flow velocity close to 6 ft/sec, but I don't know if the bare minimum is a good idea here. Also, I might have got the calculations wrong and ended up with nonsense...
4. Is the "bond beam" of a steel wall pool the same thing as the top metal ring where the coping is attached, or is it a separate concrete collar poured over the backfill around the top of the pool? If it's the metal ring, is it absolutely required to pour a concrete deck over/around it? I'd prefer to lay bullnose pavers, either in a mortar bed or attached to the steel beam with adhesive. Can that work instead?
Thanks to any and all who can help!
Sim
1. Where I am in northern VT, the soil is very sandy. The builders I've contacted have all recommended backfilling around the pool with excavated sand. One told me that he'd had a local engineering firm do a compaction test and got compaction of better than 100%. Since 95% is all that's required, and sand backfill is the general practice here, am I likely to get any significant benefit by insisting on gravel?
2. It's been dry recently, but we've had very wet years where the water table was well above where the bottom of the pool will be. Is it enough to put a pea gravel pit with a foot valve and drain pipe below the deep end so I can pump it out, or are french drains also necessary? How much do I need to worry about keeping ground water away from the wall panels?
3. None of the kits I've found for 20x40 rectangular (~33,000 gal.) pools show looped returns in their installation instructions. In fact, they often have only two returns in the kit. How many returns and skimmers are best for a rectangular pool that size, and are looped returns always a good idea? I'd like to be able to turn the water over in 6 hrs, which comes in at about 92 gpm. Three 1.5" returns fed by a 2.5" pipe should be able to handle that with max. flow velocity close to 6 ft/sec, but I don't know if the bare minimum is a good idea here. Also, I might have got the calculations wrong and ended up with nonsense...
4. Is the "bond beam" of a steel wall pool the same thing as the top metal ring where the coping is attached, or is it a separate concrete collar poured over the backfill around the top of the pool? If it's the metal ring, is it absolutely required to pour a concrete deck over/around it? I'd prefer to lay bullnose pavers, either in a mortar bed or attached to the steel beam with adhesive. Can that work instead?
Thanks to any and all who can help!
Sim