Does bare drywall need to be primed before painting?

Question

Is it necessary to prime bare drywall before painting? And do we need to prime existing textured, painted walls before we mud over them?

Answer 1

Yes, you need to use a drywall sealer on bare drywall. Using a primer or a sealer would also help blend in the differences with the existing surface you want to cover.

http://www.ehow.com/about_6636020_drywall-sealer-vs_-primer.html

Answer 2

In the UK, you don’t need to prime bare drywall or plaster before painting with normal emulsion paint. However the first coat will soak in and you will need a few more coats. (If you are using a very high spec paint that is thicker you may find that the first coat does not stick well without a mist coat, but I would always use a cheap paint for the first coat anyway.)

The normal advice is to use cheap MATT emulsion paint, watered down a bit, for the first coat as this will act as a sealer. Also if the plaster has been polished and is very smooth give it a quick light sanding will help any paint to stick well.

Answer 3

You do not need to use a Primer on bare drywall. I have painted numerous new houses, including mine, over the last 10 years and never have I primed the bare drywall. No issues what so ever. 2 coats of any good latex paint will be fine, no question.

If you were going to be painting over existing paint, it would certainly help and can save an extra coat or two of the new color. Also a good thing if you are painting over a wall that had wallpaper removed. Also good if you are paining on really old walls that are extremely dry and may soak up a lot of paint. But it doesn't sound like any of that applies to you.

People will argue that Primer is cheaper than good paint, so use the primer and save a coat of the expensive stuff. I can see that argument. But in my case, I would rather save time and stick to the same paint, rather than having to clean all the equipment and start over, especially if you are doing it the same day.

For your second question, primer might be a good idea before you mud over the textured / painted walls. Mud sometimes has a hard time sticking to painted surfaces. You could also give it a light sand that would help it stick. We reciently had to have our ceiling redone, and the drywaller had concerns about it sticking. Rather than priming it, he did a light sand, then used DuraBond to mud the ceiling rather than standard joint coumpound. DuraBond supposedly makes a better bond, seals out moisture/humidity, and reduce cracks/blemishes over standard compound.

Good Luck!