Using 2 x 10 treated lumber for decking
I am tearing down a large deck and have an abundance of 2 x 10 treated that are in excellent shape.
Can I build a new deck that is 12' x 14' using all 2' x 10" boards including floor decking?
Do I need to rip the deck boards down to prevent warping?
There is certainly no problem using the 2x10s for any of the structural framing of the deck. Using 2x10 treated lumber for decking is another matter entirely.
I would not recommend them for decking.
Firstly, the species of lumber is problematic. Pine is the common pressured lumber. In the west, you will see more more hemlock fir. But pine, especially southern yellow pine can warp quite a lot.
The larger the growth rings the more unstable the lumber is. A 2x10 as a decking board that must lay flat and never cup or warp is asking it to do something completely out of its character.
I know you want to save some money but you won't be saving any if you use the 2x10s for the decking. Be glad you saved a bundle re-using them for the entire framing structure below and save the rest for another project or sell them in an online classified add for used lumber.