Primers
Primer types, and when each one is actually needed.
Primer is the coat most people skip over in a quotation, and it's the one that decides how well everything on top of it holds. Different surfaces need different primers.
Reviewed 21 September 2026 by PremiumWalls operations.
At a glance
What does primer do, and which type do I need?
Primer seals the surface, helps paint grip it, and evens out how much paint the wall absorbs. The type depends on what's underneath: water-based or cement primer for fresh plaster, a sealer-type primer for stained or patchy walls, and separate primers for metal and wood. The exact product is chosen after inspecting the surface.
Primer Types and When Each Is Needed
What a primer is doing
A primer is a working coat, and the colour on top of it does none of these jobs. It seals a porous surface so the paint doesn't soak in unevenly, it gives the finish coat something to grip, and it can block certain problems like stains or alkali from coming through. Skipping it usually shows up as patchy colour and early failure.
Water-based or cement primer for fresh plaster
New cement plaster is porous and alkaline. A primer made for that surface seals it and holds the alkali back from attacking the paint above. It's the usual starting point for a new building or a freshly plastered wall, once the plaster has been given enough time to cure.
Sealer-type primers for stained or patchy walls
Where a wall has old stains, patchy repairs or a mix of surfaces, a sealer-type primer helps even it all out and stops marks bleeding through. It's often used after repairs, where fresh patches and old paint sit side by side and would otherwise take the finish differently.
Metal primers
Gates, grills, railings and metal almirahs need a primer made for metal, and it usually matters that rust is dealt with first. A wall primer on steel won't protect it. Metal primers are formulated to bond with the surface and slow further corrosion.
Wood primers
Doors, window frames and wooden furniture take a primer suited to wood, which seals the grain and gives the finish coat a smooth, even base. Bare wood soaks up finish unevenly without one, and knots and resin can mark the surface later.
Why the product is specified after inspection
The right primer depends on what the wall is actually like: how fresh it is, whether it's damp or stained, what's already on it and what finish is going over it. Naming a product over the phone would be a guess. After a free inspection, the quotation itemises the primer for each surface.
Primer Types and When Each Is Needed — your questions.
Can I skip primer if the paint says 'self-priming'?
Sometimes, on a sound, previously painted wall in good condition. On fresh plaster, patchy repairs or stained surfaces, a proper primer still does work that the finish coat can't.
Is one coat of primer enough?
It depends on how porous the surface is and what it needs to seal. Very absorbent or heavily repaired walls may need more than a lightly absorbent one. The inspection gives a clearer answer.
Can I use wall primer on my gate or grill?
It's not the right product. Metal needs a primer formulated for metal, applied after rust has been dealt with, or the coating won't hold.
Does primer stop dampness?
No. Primer isn't a waterproofing layer. If moisture is coming through a wall, it has to be treated at the source first, or it will push through the primer and the paint.
Let us look at your walls first.
Tell us about the property and we will set up a free colour and wall inspection. You get a written, itemised quotation afterwards, with no obligation to go ahead.
- We call you back the same day to get a picture of the property and the surfaces.
- We agree a time and come out for the free inspection.
- You get the written scope and itemised quotation.
- Nothing starts until you approve it.