On 9/29/2012 12:41 PM, Existential Angst wrote:
I've read you have to delay painting PT lumber from everywhere from two
weeks to a year. Latex paint...
What's the deal?

PT lumber is typically very very high in moisture content. Read that as
often soaking wet. Paint needs to stay dry on the side that it adheres
to a surface. If moisture saturates the surface under the paint the
paint will fail.




And, how does one tell if PT wood is ready to be painted?
It feels quite wet from the lumberyard/HD, but seems much drier in a cupla
days.
Does rain further extend the wait?
Does a sprayer allow you paint sooner than brushing/rolling??

Use a moisture meter or wait at least year. Method of application has
nothing to do with how long the paint will last on a poor surface.

That said some better lumber yards, not home centers, carry kiln dried
PT lumber, this is what you want if you want to paint right away.



Also, just curious: Will non-PT wood last as long as PT wood (outside, of
course), if it thoroughly painted?

That will depend on the wood. Fur, SYP, mahogany, ipe, cedar are a few
commonly used woods for out door use with no protection or paint.