Painting - painting pressure treated lumber

I have to replace some outside trim wood which has rotted over the years, I'am going to replace it with pressure treated lumber. Can I paint pressure treated wood without any type of prep?

dftodd

Don't even think about painting fresh pressure treated wood. The moisture in it stacks the deck against good paint adhesion. Seal your project with a pressure treated wood preservative immediately. Follow the preservative's instructions regarding future painting, making special note of the amount of time the preservative should weather before painting.

Should have an oil base primer on it. Best to let it weather a little and dry out before painting.

What kind of trim boards?
I would use a fiber cement board or wood and prime and backprime caulk and paint. No need for pressure treated.

Pressure treated is protection against insects not water damage.That is why you need to seal decks. If the rot is from water damage I agree with Trey pressure treated is unnecessary and serves no purpose. If the damage is fome insects you need to eliminate the insects before you do anything, if not they will find something else to eat like studs and joists.

It would have been good to know why these boards rotted in the first place.

Always prep. Skipping t he prep leads to premature failure. Me thinks that skipping th eprep caused the boards to rot in the firt place (or at least contributed to it).