Signs Your Brickwork Needs Repointing: What to Look For

Run the key test: is the mortar soft or receding?

The simplest check costs nothing. Take a key or flathead screwdriver and drag it firmly along a mortar joint at chest height, then again near the ground where walls stay wetter. Sound mortar resists and leaves barely a mark. If it scratches out easily, crumbles to sand, or flakes away in chunks, the binder has broken down and that section needs attention.

Also look at the depth of the joints. Fresh pointing sits flush or slightly recessed from the brick face. Once joints have worn back more than about 10mm, rain can sit on the ledge of the brick below and track into the wall, which speeds up the decay of everything around it.

• Mortar that rubs off as powder on your finger
• Joints recessed deeper than roughly 10mm from the brick face
• Hairline gaps opening between mortar and brick edges
• Whole sections of mortar missing, often below window sills and at gable ends

Damp patches, salt stains and green growth

Failed pointing often announces itself indoors before you notice it outside. Damp patches on internal walls, peeling wallpaper in one corner of a room, or a musty smell in a chimney breast frequently trace back to open joints letting rain through the outer leaf. On solid-walled Victorian and Edwardian terraces, which make up a large share of housing in areas like Kings Heath, Erdington and Handsworth, there is no cavity to catch that water, so it comes straight through.

Outside, look for white powdery deposits on the brick face, known as efflorescence. This is salt carried out by water moving through the wall, and it tells you moisture is getting in somewhere. Moss and algae clinging to joints on a north-facing or exposed wall are another clue, because they only thrive where mortar stays persistently damp.

Spalled bricks: the sign you have left it too long

When the faces of bricks start blowing off, leaving a rough, pitted surface, that is called spalling, and it usually means water has been getting in for years. Water trapped behind hard mortar or entering through failed joints freezes in winter, expands, and pops the fired face off the brick. Once the face is gone, the softer core absorbs water even faster.

This matters because spalling changes the job from repointing to brick replacement. Cutting out and matching individual bricks on an older property costs considerably more per unit than raking out and refilling joints, and matching reclaimed bricks to a weathered wall takes time. Catching failed pointing before bricks spall is the single biggest saving you can make.

• Brick faces flaking or crumbling, especially on chimneys and parapets
• Pitted bricks below a leaking gutter or downpipe
• Cracks running through bricks rather than following the joints, which may indicate movement and needs a professional look before any repointing

What repointing involves and what it costs

Proper repointing means grinding or raking out the old mortar to a depth of at least 15 to 20mm, brushing and dampening the joints, then refilling with a mortar matched to the wall. On pre-1930s houses that usually means a lime-based mix, because hard cement mortar traps moisture in soft bricks and causes the spalling described above. A surprising amount of damage we see locally comes from cement repointing done in the 1970s and 80s.

Costs depend on access, wall condition and mortar type, but as a rough guide most repointing in the West Midlands falls between £40 and £70 per square metre, with lime work at the upper end. A full gable wall on a typical terrace might run £1,500 to £3,000 including scaffold, while patch repointing a few square metres around a bay window is often a few hundred pounds. Any figure should come from someone who has actually looked at the wall.