DIY treating untreated lumber for deck usage?

I need to build two decks on my house under construction. I have a small pile of 2x10s left over among other lumber. Are there any good products out there I could use to treat these for use on a deck? One of the decks is fully tucked under a roof with walls. I’m sure I could find another use for the lumber if this isn’t feasible. Just hoping to clean up some space and make use of materials on hand.
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Replies
My guess is the cost of any affective product will exceed the cost of new TP lumber. Consider how much work it would be if the boards did rot after you treated them. The risk VS rewards does not work for me.
Walta
Second @Walta100's comment. Do not frame a deck out of untreated 2x10's
Chances are that your ceiling joists are 2x8's or 2x10's. If you have a vented attic, current code required insulation (or more than code required) is going to be thicker than the ceiling joist height and thus the joists are buried under the insulation. This makes it difficult to move around the attic for maintenance issues. You can cut your extra 2x10's and install them perpendicular to the ceiling joists to create small paths from the attic access to any attic elements such as a radon vent, or to create storage areas near the attic access. Use some extra floor decking to deck it the paths and storage area...
Tim_O,
Surface applied treatments should be reserved for sealing field cuts in PT lumber.
Thanks all, I'll stick to pressure treated!