we use troughs for all of our lizard setups. they are watertight, indestructrible, and very economical. they are the perfect base to build around, and up from.
Home Depot often carries smaller horse/water/cattle troughs/stock tanks (they call them different things in different places), otherwise check your local feed store, farm supply, horse and tack, etc.
our most common size that we use is 4 ft long, 2 ft wide, and 2 ft high. you have to make your own lid, but that gives you the flexibility to do something "breeder" style, or something more ornate and decorative (and perhaps front viewing) for a home display setup.
the depth allows for great substrate and digging, and they come in sizes up to 15 ft. we use the oblong shapes most often, but for those large troughs in the above pics, we got circular 10 footers.
as for the wood construction, i designed that and had our carpenter guy build it. i based it on skateboard ramp construction (the old days 
) and the wrap around ply is just some flexible 1/8 inch stuff that was fairly moisture resistant. there is more bracing, and a 3/4 inch piece on the inside in between each stud to provide more rigidity and security, and the whole thing is wrapped in two metal tension bands.
you can see more details and construction pics at our site, look in the Ionides Monitor and Facility photo galleries.
definitely consider the troughs when looking to make a 3 ft or larger cage, they are great
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robyn@proexotics.com
Pro Exotics Reptiles
