Chuck W1CEW wrote:

We have pressure treated wood stairs leading up to our front door from
the street level. At some point someone decided to paint that
material, and EVERY year, I have to repaint, because the paint doesn't
seem to really "stick" well to the pressure treated wood material. It
peels off in ugly patches. Not how I want my front entryway to appear
of course! One thought I had is to replace the most visible pieces,
(stair treads and rails) with new composite planks. However, I am not
sure it is possible or advisable to mix and match these materials?

Pressure-treated wood paints pretty well, as long as it's prepped
properly. That would include a good cleaning, sanding where needed, and
the proper primer before the paint. Oh, and you're supposed to wait
three months or more before painting new PT wood--it's too wet
otherwise. I bet that someone in the past skipped the prep steps, just
slapping on a coat of paint, and you have to suffer for their laziness.

I recommend you take your problem to a real paint store. The people
there will have lots more experience than the highschool student at the
big box store[1].

Here's my suggestion:
* Power wash the steps to get stuff loose (and clean). Let dry.
* Scrape to get off the stuff you just loosened up.
* Sand the entire thing to get rid of the edges where paint chipped.
* Wash with tri-sodium phosphate (TSP).
* Caulk
* Prime
* Paint, two coats

If you really want to replace the wood, composite should do fine. Check
with the supplier first to find out whether it takes paint. Composite
is a mixture of sawdust and plastic, so you might have to do something
special with it.

[1] To be fair, I _have_ occasionally found good paint people at the
borgs, but it's rare.

--
Steve Bell
New Life Home Improvement
Arlington, TX