Painting brick: what it costs you later

Painting brick is close to a one-way decision. Getting the paint back off masonry costs several times what putting it on cost, and the two methods that actually work, abrasive blasting and repeated chemical poultices, take the fired face off the brick, which does not grow back.

That does not make painting brick a bad idea. It makes it a decision to take once, with your eyes open, knowing you have moved a wall from a surface with almost no maintenance to a surface that needs repainting for as long as the house stands.

Why can you not just strip it off later?

Brick is porous. A fired brick has a harder skin on its face, and behind that skin the body of the brick behaves like a hardened sponge. Paint keys down into that pore structure rather than sitting on top of it.

Blasting removes the paint by removing the surface the paint is keyed into. What you are left with is an open, roughened face that absorbs water faster than the original brick did, and where the face flakes away in sections you get spalling, which is permanent. Chemical stripping is gentler and it is what conservation work uses, but it means poultices left on the wall, repeat applications, a great deal of rinsing, and a result that is rarely completely clean. Both routes cost far more per square metre than the painting did.

What are you actually signing up for?

	Unpainted brick	Painted brick
Maintenance cycle	Little beyond washing, and repointing every few decades	Repainting on the same cycle as any other painted exterior
How it ages	Darkens and weathers slowly, mortar erodes first	Fades, chalks and collects grime on sheltered faces
What failure looks like	Mortar joints crumbling before the bricks go	Flaking, usually starting at mortar joints and parapets
Changing your mind	Paint it, at normal exterior painting cost	Strip it, at several times that cost, with permanent risk to the brick face
How the wall dries	The brick face dries freely	Depends entirely on which coating was used

Does painting brick trap moisture?

It depends which sort of wall you have, and in New Zealand there are two very different ones.

Brick veneer is a single skin of brick standing in front of a timber frame, with a cavity and a building wrap behind it. The veneer is not waterproof and was never meant to be. Water that gets through the face runs down the back of the bricks and out through weepholes at the bottom, and air moving through the cavity dries the wall. Painting the outside face of a veneer is comparatively low risk, because the drying is happening in the cavity rather than through the brick.

What you must not do is block the weepholes. They are the gaps deliberately left in the vertical mortar joints of the lowest course of bricks. Filling them with paint, sealant or a render skim sends water that got in behind the bricks back towards the framing instead of out to daylight. Any painter working on brick should be able to point out your weepholes before starting.

Solid masonry, meaning double brick with no cavity, is the harder case. The wall itself has to dry outward, so an impermeable film on the face traps moisture and salts inside the brick. That shows up as efflorescence, then blistering, and eventually as the paint taking brick face with it when it lets go. On this kind of wall the coating has to be breathable, and a heavy elastomeric membrane is the wrong product.

What does this mean in Wellington specifically?

Most brick around this region is veneer on houses built from the 1960s onward, which is what you see through Churton Park, Grenada, Tawa, Whitby and much of the Hutt Valley. The older solid masonry stock is smaller here than in other cities, partly because of what earthquakes and strengthening rules have done to it over the last century.

Two local checks are worth making before you commit. If the building is unreinforced masonry and there is any seismic strengthening in its future, do not paint it first. Strengthening, repointing and tie installation will cut a finish to pieces, and you will pay for the wall twice.

The second is exposure. South and west elevations here take wind-driven rain that flatter, sheltered cities do not get in the same quantity. A coating on those faces is doing real work and will show wear well before the sheltered sides do, so plan your repaint cycle around the worst elevation rather than the average of the four.

If you are going ahead, what does the job involve?

• Fix the water first. Painting a wall that is damp, efflorescing or sitting under a leaking gutter locks the problem in behind the film.
• Repoint failing mortar before painting. Paint over crumbling joints hides the failure without stopping it, and the joints are where the coating fails first anyway.
• Wash properly and treat moss and lichen. Brick holds both deep in the pores.
• Seal first. Brick is thirsty and will drink an ordinary first coat straight in, which is why a masonry sealer coat is normal rather than optional.
• Expect poor coverage. Textured brick and open mortar joints take considerably more paint per square metre than flat weatherboard, and the joints usually need brushing rather than rolling.
• Choose a breathable masonry finish rather than the most film-forming product on the shelf.

What does it cost, and when is it not worth it?

A full exterior repaint in Wellington sits in the $6,000 to $20,000 and up band in 2026, with condition and access moving that figure far more than the wall material does. Brick tends to push a house towards the upper part of whatever band it would otherwise sit in, because of the sealer coat and the coverage rate rather than any exotic product.

Reasons not to spend the money at all:

• The brick is sound and you simply do not like the colour. Live with it one more summer before committing, because this is not easily undone.
• You are selling within a year. Painted brick divides buyers, and the ones who wanted brick will read it as something being covered up.
• The mortar or the flashings need attention. Do those first, then decide.
• Only part of the house is brick. Painting brick to match weatherboard often looks worse than letting two materials be two materials.

Is there a middle option?

Yes, and it is underrated. A clear water-repellent treatment penetrates into the brick and cuts water absorption while still letting vapour out, so the wall stays brick coloured and stays breathable. It does nothing about a colour you dislike, which is usually the real motivation, but if damp or staining was the reason you were considering paint, it is the cheaper and reversible answer.

Washing is the other one. A good deal of brick that people want painted is simply dirty, and a proper wash with a moss and mould treatment takes ten or fifteen years off a wall for a fraction of the cost of coating it.

If you have a brick or part-brick house and want a straight answer on whether painting it is the right call, our exterior painting team will look at the wall type, the weepholes and the mortar before quoting anything. Ask us to take a look.