Do I need 2 coats of primer on new drywall? Homeowner is using primer/paint on finish coat. Will the primer/paint suffice, instead of 2nd coat of primer?
This is for all new surface. walls, ceilings & trim.
It really depends on the results you get after the first coat. The purpose of primer is to lay down a surface that is uniform and consistent in
Because if those things are not uniform, the irregularities will print through when you topcoat.
You can get it to stop printing through if you spam enough coats of topcoat... But since that's primer's job, it's better to resolve it at the primer stage, where you are sure to get it in 1 or 2.
You only ever need 1 coat of primer. Many times you'll need 2 (or 3 or even more) coats of paint to get good coverage, depending on the color, but priming is only done once.
On existing walls that currently have paint, you may not even need a primer coat - especially with all of the paint+primer products out there now.
primer + paint is a bit misleading. All paint (even older paint not billed as having primer) contains the polymers to "stick" to each other (premium paints contain more of them so, in theory, it takes less coats). The catch there is that paint itself is not cheap (you're using a final coating product as an undercoat).
For new drywall, primer is really essential. New drywall is pretty porous (it will absorb more of the paint than a previously painted wall would) and primer helps fill that in before you paint. The good news is that they make a "new drywall only" primer (example) that's pretty cheap (compared to a bucket of normal paint) because it's only trying to fill that porous-ness, not do other things normal primer does, like provide adhesion over something like an oil/wallpaper glue stain.
I always prime with a quality primer , use cheap stuff & you pay in the long run using more topcoat than primer. especially an older house with plaster walls , depending the last time it was painted , you will see the walls "sucking " in the paint ,only sending you for more paint. It can become an expensive project , I always prime new drywall and especially the spackeling ,this uses a few coats . I laughed when they started advertising "paint with primer", like it magically seals the walls ,lol