Priming is a required first step before many painting jobs and even on newly installed bare drywall.
Existing, painted drywall may not need a primer under certain conditions.
The Spruce / Margot Cavin
Is Primer For Drywall Necessary?
The Spruce / Margot Cavin
New, unpainted drywall requires priming with a drywall primer before painting.
Painted drywall may or may not need priming depending on the condition of the paint.
Priming drywall is fast, inexpensive, and effective.
Glossy surfaces may require a primer.
When changing from a dark to a lighter color, primer reduces the number of color coats needed.
What Drywall Primer Does
Drywall primer helps even out the variegated colors inherent in standard bare drywall.
Since drywall is also porous, it will absorb the paint unevenly at different speeds if left unprimed.
The primer helps the paint soak into the drywall at an even, consistent rate.
Drywall primer will significantly reduce or eliminate that effect.
Drywall Primer-Sealer
A coat of a 100% acrylic primer-sealer is recommended for new drywall.
Drywall primer-sealers come in water-based (latex) and oil-based (alkyd) forms.
Standard sealers are appropriate for perfectly smooth and well-finished walls.
High-build primer-sealers fill in rough or uneven drywall finishing.
Paint stores may be able to add pigments to the sealer-primer, sometimes for a small additional fee.
PVA primers grab onto drywall paper better than latex paint does.
PVAs are sealers that aid with adhesion more than they are color blockers.
PVAs may incidentally cover stains and discolorations but that’s not their job.
As such, stains may lightly show through.
Flat Latex Paint
Using flat latex paint is another inexpensive way to prime drywall before painting.
Some drywall manufacturers recommend plain flat latex paint as one bang out of drywall primer.
The cost of a gallon of basic flat latex paint is usually considerably less than top-quality finish paint.
As with a primer-sealer, tint the flat white latex paint to closely match the finish color.
Hiding Paints
Hiding paints take the concept of flat latex paint one step further.
Choose a hiding paint that is compatible with unfinished drywall.
Hiding paints may cost twice as much as ordinary flat latex paint.
Cost Savings
Drywall primers will cost on average $20 to $25 per gallon.
Premium paints cost on average $60 to $100 per gallon.
Drywall primers cost three to four times less per coat when compared to premium-paint color coats.
This unevenness only disappears after multiple layers of expensive paint.
Choosing the Best Primer for Your Drywall
Each primer has its purpose for the optimal results.
Determine the condition of your drywall and where it’s located to determine the best primer.
Always check the primer manufacturer’s label for the best applications.
The skim coating does not replace priming; a prime coat is still needed over a skim-coated wall.
Use a dedicated drywall primer or a PVA sealer on bare, unfinished drywall.
One gallon of drywall primer covers 250 to 400 square feet of new drywall.
Apply drywall primer with a roller or paint sprayer as you would regular primer.
