homer2654 wrote:
....

1. Can I avoid shrinkage, warping, and twisting if I use special
pressure treated + redried wood and immediately stain it, or does
redried wood also shrink and warp to some extent?

"Dried" construction lumber isn't dry in the sense of hardwood, only
partially and is (supposed) to be kept from getting rained on again
(although that's certainly not guaranteed by most chain stores). It
_will_ shrink and unless it's held down, almost certainly will
warp/twist at least some--it is lumber, after all. You can minimize
the effect by buying it and storing it in a dry, relatively protected
place and making sure it is well stacked and preferably stickered and
weighted while it finishes drying out. How long that would take would
depend on the climate you're in--if it's hot, that's good, if it's very
humid, that's not so good. Sealing it immediately is the wrong
direction--the lumber moisture _will_ have to get out, you want to
allow it to do so but in a controlled fashion, _then_ you can attempt
to minimize external moisture later for protection.


2. Will I avoid shrinkage, warping, and twisting if I use the non
re-dried wood from HD and immediately seal it (even though it's wet)
with sealers approved for immediate sealing, like Wolman's "raincoat?",
or will it still shrink etc?

No, see above. You will only change the rate at which it dries and
probably exacerbate the warping. The amount of shrinkage is dependent
on the initial water content and the species and (to a lesser extent)
the ambient humidity of the region you're in--equilibirium moisture
content is lower in AZ, say, than FL.

You can control the amount of warping of any given piece only by
controlling the rate of the drying process and by mechanically
restraining the material during that process. Depending on the grain
and how any particular board was sawn from the tree, (which is done for
construction lumber to maximize yield, not for how the grain runs,
etc.) some pieces may be essentially impossible to prevent from bowing
almost double, others will just show a little cupping and others (those
very few that just happen to be quarter-sawn for the most part) will
just shrink a little.