I buy FRP at truck body repair shops, or diretly from truck box manufacturers like Supreme or Morgan.
You could laminate it with fiberglass weave with a strong adhesive (polyester).
Fiberglass is lighter, AND stronger.
spruce
Every insulation has a different R value. It ultimately is determined by which insulation you will be using. Now lets do rough estimate. 4" thick, regular fiberglass mat has R-value of 13. Assuming that plywood has the same to half the insulating value of fiberglass, 1/2" plywood would have 1/8 to 1/16 of R-value of that 4" mat. Roughly R-1.6 to R-0.8
The general practice, is to leave the underside of plywood decking bare, as this allows the wood to breathe, and be able to dry out. When using treated, or marine grade plywood, only one side, usually the top side, is sealed.
A galvanized steel wall is superior to plywood. A fiberglass (polymer) wall is far superior to both. Good luck with your pool.
Historically, the best wood for ANY boat was: Whatever was most available. Various types of plywood coated with fiberglass is an excellent choice.
http://www.doityourself.com/stry/cutting-out-a-fiberglass-bathtub has advice on how to cut out a fiber glass bathtub by yourself. Be sure to follow their safety tips like having gloves. Diamond blades, power saws, appropriate clothing and safety gear are essential when you want to cut fiberglass. Use a of a piece of scrap plywood as the base for cutting and use fiberglass power trimmers when cutting fiberglass panels. You can know much information and details about fiberglass cutting at the link: http://www.ehow.com/how_4449106_cut-fiberglass.html;
There are 48 plywood manufacturing plants, as well as 17 wooden board factories in Mexico. Most of them are found on the northern states of Durango (23%) and Chihuahua (19%), and the eastern state of Campeche (10%).
Apexvs. Plywood used in houses, which contains wood pieces glued together in different directions
Yetiply offers a wide range of plywood, including marine plywood, commercial plywood, and decorative plywood and it is known for Plywood Manufacturers In India. We cater to various needs, from construction to interior design.