Just installed Azek beadboard to (spare) bathroom ceiling because we couldn't install a fan without major work...thought Azek would help control mildew/rot problems in steamy bathroom. Noticed the sunken finish nails are starting to rust. What do you suggest we do to control the rust that is starting on the sunken finishing nails and what is the best way to prep and paint the Azek. Was hoping NOT to have to paint the ceiling, but the nails couldn't be hidden and the crown molding turned out to be slightly different color than the beadboard anyway. So the whole reason for installing the Azek (so as not to have to paint ceiling) is turning into a nightmare.

Also, am I reading other threads correctly when I see that caulk can be used in nail holes as well as putty? Which is better when trying to stop rust from bleeding through?

Thanks,
Moe

 

Caulking is for cracks/joints and putty is for nail holes.

The putty should hold out the rust but it would be a good idea to coat everything with a pigmented shellac primer which will give further protection from the rust bleed thru and insure better adhesion to the Azek. Top coat with a good latex enamel.

 

One of the problems with Azek is the exposed nail/screw heads
As far as I know Azek still has no recommendations for this
I have tried, with some success, latex lightweight spackle (small) and wood epoxy and filler (large)
The wood epoxy/filler is sort of a pain as you must sand them smooth if not applied nearly perfect
And, of course, you can't (shouldn't) sand the Azek, as texture anomalies appear



Another problem is painting
Prepping for painting, you must make sure the Azek is clean, clean, clean
I haven't yet found the ideal cleaner, but solvents mild enough not to affect the Azek seem ideal so far
Though if the Azek is relatively clean to begin with, simple household cleaners like Windex seem fine
As far as I know Azek has not recommended a cleaner

The paint itself is not easy either
It used to be that Azek recommended SWP Duration and Superpaint only
Then it switched to (or added) Pittsburgh Manor Hall
Now I believe the recommendation in SWP Vinyl Safe paints

All I can say about that is I have used Duration and Manor Hall
It works, but it's not easy or fast, one must go carefully
Even if it's the same color, you'll need two coats
No primer is recommended



Another problem is mold and mildew
I've noticed the exposed, cut, ends of Azek attracts and collects mold and mildew in moist environments
Either there is wood product in the material for food, and I believe there is, or the cut ends collect and hold other food materials (pollen, etc.)
Best to make sure any/all cut ends are well sealed



Another problem is caulking
I'm not aware of Azek recommending any caulk, other than their own glue/adhesive
I've used that with success, but it's not a caulk really, and I haven't used it "after install" like a caulk

I have used a regular top quality caulk on Azek, but only after it was painted



I say "as far as I know" when referring to Azek's recommendations a lot, as the Azek recommendations seem to change
What I have written here attributed to them is current for the moment
Also, the suggestions I made not attributed to Azek are my own observations from working with the materials