I really don't think there is such a thing as a mildew resistant primer and this makes sense to me as being something that is not needed because mildew will not grow on primer. The primer is under the paint that you use as a topcoat so when will primer ever be exposed to moisture? In order for mildew to grow, moisture is required. I think the recipe for getting your paint to hold up nice in a high moisture environment is using high quality products like a top line primer and a top line paint. You can add a packet of mildewcide to whatever paint you choose to use as a topcoat which should make it resistant to mildew or you can buy Zinnsers Bathroom Paint which already has that added. I'm sure other paints have mildewcide in it already too. I like hot showers too and I have a shower in a very old house with a painted ceiling in it. It's holding up great for 7 years now and I never even used mildewcide. I guess if you can have a bathroom where moisture doesn't sit around for long periods (it dries completely after each shower) then you will be good.

Hi paintguy,

Thank you so much for your reply!! I am very new to this, so I really appreciate your advice!

What is considered a top line primer and top line paint? Because I will buy that! The space is not big at all.

I was planning on painting the panels a Benjamin Moore off-white colour called gray mist, swiss coffee or white dove. Is this not a top line brand though? Is Zinnsers easy to work with, and is it worth buying?

If I added the mildewcide to the top coat paint - does that change the consistency of the paint or make it more difficult to work with?

I am installing the boards on plywood - does it make sense to buy waterproof plywood (that they use in boating useages), or it wouldn't matter?

Thank you so much!

Rhea

here is what you want

Here is a link that might be useful: ben moore

No, mildewcide does nothing to make application harder. I would probably use Fresh Start primer by Benjamin Moore and the Aura for the topcoat. If you are painting plywood, it will become waterproof after you have primed and painted it.

fwiw - Ive had good luck with the Zinsser bathroom paint - in fact we had it over plaster and wood trim IN a shower as an interim thing and it held up surprisingly well for a couple of years with periodic touch ups (not recommended though - we re did bath at first opportunity) The SW bathroom paint on the walls peeled long before the Zinsser did. Tinting though is limited to pastels though which means if you want some color and pizazz in your bathroom you might need to look elsewhere.