I've built many decks in past for myself and customers. Not really rocket science...lol. There are some basic givens:
- 1. Need footings for posts (or) set posts in concrete to support "floor joists".
2. Install floor joists after installing perimeter(s) boards to affix joists too.
3. Install deck boards onto joists with coated screws (drill holes in boards, then screw them into joists) Don't drill into joists.
4. Use metal "framing brackets" (aka joist hangers) to attach joists to perimeter boards.
A Special Note: If you are not readily familiar with measuring, layout, using power saw, using an electric drill to install screws, then you need someone to help and/or do work for you.
Notes:
- A. Use 2x6" lumber for perimeter, joists, and decking. (Check with someone on the "correct" span for joist lumber...2x6" lumber "generally" ok upto a span of 12' or so).
B. Posts should be no further apart than 8 ft.
C. Joists should be about 24" apart.
D. Screws should be special "teflon coated" (or similar) for anti-rust.
E. Perimeter joists need to be spaced as hexagon, octagon, etc. to go around round pool (to keep construction simpler).
F. Use treated lumber (if "allergic or opposed to 'chemicals'") use construction heart redwood. If using redwood rather than treated yellow pine lumber, then you need to "upgrade" size of lumber, e.g., 2x8" or so. Redwood has less strength than yellow pine.
G. After deck completed, treat with one of the special water-repellant "chemicals" (petroleum based) as extra insurance against water penetration.
H. Upright posts that are set in concrete should be high enough to affix a railing around the outside perimeter of deck (probably 36 to 48" high above deck floor).
Draw out your deck plan using a "scale", such as 1" = 3' , or your choice. Then, draw all joists in to scale. Then, simply measure the total footage of all boards and divide by whatever length you plan to buy (e.g., 12' , 16' etc.).
If these instructions don't compute for you, go to a store and buy a "deck plan book", select the design, and then leave it up to the store to tell you what you need...
A caveat: One should generally purchase 5% more lumber than you "think" you will need (otherwise, due to cutting issues, you may find yourself going back to the store 1 or more times...
Good luck!