How long do bricks last?
Fired clay bricks are one of the most durable building materials known. In ideal conditions, bricks can last for hundreds of years. Many Roman, medieval and Victorian brick structures are still standing with their original bricks largely intact.
However, bricks vary considerably in quality. Soft, under-fired bricks are more vulnerable to frost damage and water absorption. Hard, well-fired bricks — such as engineering bricks — are almost indestructible in normal conditions. Most modern facing bricks fall somewhere between the two.
How long does mortar last?
Mortar is the weak link in brickwork. It is designed to be softer than the bricks, so it weathers and erodes before the bricks do. This is deliberate — mortar is sacrificial.
How long mortar lasts depends on several factors:
- Mortar type: lime mortar on pre-1920 buildings typically lasts 50–100 years before repointing is needed. Modern cement mortar lasts 20–50 years.
- Exposure: exposed, south-facing or unprotected walls weather faster than sheltered ones.
- Quality of original work: properly mixed and applied mortar lasts far longer than a rushed job.
- Wall design: walls with copings, overhanging eaves or a roof drip edge are protected from the worst rain exposure.
Signs your brickwork needs attention
Crumbling mortar
The most common and straightforward sign. Press your finger into the joint — if mortar crumbles or comes away easily, it is time to repoint. Left unattended, crumbling mortar allows water into the wall, accelerating damage to both mortar and bricks.
Spalling bricks
Spalling is when the face of the brick breaks away or crumbles. It is caused by water freezing inside the brick. Once a brick is spalling, it needs to be cut out and replaced — repointing alone will not fix it. Spalling is most commonly caused by using cement mortar on older soft bricks, which traps moisture rather than allowing it to escape.
Efflorescence
Efflorescence is the white, powdery or crystalline deposit that sometimes appears on brick faces. It is caused by soluble salts in the brick or mortar being drawn to the surface by moisture. In itself it is not harmful, but it indicates that the wall is damp. Investigate and address the source of moisture.
Cracks
Not all cracks are serious, but they should be monitored and assessed. A useful guide:
- Hairline cracks in mortar joints: usually settlement, often not serious
- Staircase cracks (stepping through mortar joints diagonally): usually foundation movement, often minor but worth monitoring
- Horizontal cracks in mortar joints: can indicate serious structural movement — get a surveyor to assess
- Cracks through bricks (not just mortar): indicates significant movement or loading — seek professional advice promptly
If cracks are widening over time, act promptly. A simple monitoring technique is to stick a piece of tile across the crack with adhesive — if the tile breaks, the crack is still moving. A structural engineer or surveyor can advise on the severity and cause.
Damp patches on internal walls
Damp patches on internal walls after heavy rain suggest water is penetrating through the external brickwork. The most common cause is failed mortar joints. Repointing the external wall usually resolves it.
How often should brickwork be inspected?
A simple visual check every year or two is sufficient for most properties. Walk around the outside of your building and look at the mortar joints, brick faces, and any areas that receive heavy rain exposure. Pay particular attention to chimneys, parapet walls, bay windows, and areas below gutters (a leaking gutter dramatically accelerates mortar deterioration).
Maintenance summary
| Task | When needed |
|---|---|
| Repointing exposed walls | Every 20–50 years |
| Chimney repoint | Every 15–25 years (more exposed) |
| Replacing spalled bricks | When faces are visibly breaking away |
| Crack monitoring | Annually for any visible cracks |
| Gutter maintenance | Every 1–2 years (prevents mortar damage) |
Frequently asked questions
- Can you repair spalled bricks without replacing them?
- No reliable long-term repair exists for spalled brick faces. Patching compounds are available but rarely look convincing and do not last. The correct solution is to carefully cut out the damaged brick and replace it with a matching one. This requires skill but is straightforward for an experienced bricklayer.
- Does painting brickwork protect it?
- Painting brickwork with standard masonry paint can trap moisture and accelerate deterioration — particularly on older brick buildings. Breathable mineral silicate paints are less harmful. In general, we advise against painting brickwork unless there is a compelling reason to do so. If a wall is already painted, removing the paint is often more disruptive than repainting it.
- How do I know if my wall needs underpinning?
- Underpinning is only needed if the foundations have failed or are inadequate for the load. Signs include significant cracking, walls leaning out of plumb, or doors and windows sticking. A structural engineer is the right person to assess this — do not rely on a bricklayer's view alone for suspected foundation problems.