Brick repointing Melbourne

Look for mortar that is crumbling or can be raked out with a screwdriver, joints that have eroded back more than a few millimetres from the brick face, gaps or holes in the joints, damp or staining on internal walls backing onto the affected brickwork, white efflorescence on the brick face, and vegetation or moss establishing itself in the joints.

This is the single most important thing to understand before anyone repoints an older Melbourne home. Solid brick houses built before roughly the 1930s were laid in soft lime mortar. That mortar is deliberately weaker than the bricks, so it takes up movement and lets the wall breathe and dry out.

When a hard modern cement mortar is used to repoint that brickwork, the mortar becomes stronger than the brick. Movement and moisture can no longer escape through the joint, so they go through the brick instead. The result is spalling — the faces of the bricks blowing off — and trapped damp inside the wall. It is common, it is expensive to reverse, and it is caused entirely by using the wrong mortar.

We match the mortar to the wall: lime-based mixes for solid and period brickwork, and appropriately specified cement mixes for later construction where that is what the wall was built with.

1. Assess the brickwork and existing mortar — identifying the original mix, the construction type, and any structural cracking that needs to be dealt with first.
2. Rake out the joints — removing perished mortar to a depth of at least twice the joint width, so the new mortar has something to key into. Shallow surface pointing falls out.
3. Clean and dampen — clearing dust and controlling suction so the new mortar cures properly rather than drying out too fast.
4. Match the mix — matching strength, sand colour and aggregate to the existing mortar.
5. Repoint and finish — filling the joints fully and finishing to the original joint profile, whether that is flush, weathered, ironed or raked.
6. Cure and clean down — protecting the work while it cures and cleaning the brick faces.

On period properties the finished joint has to match what is already there in colour, texture and profile, or the repointed section stands out permanently. We match sand and aggregate to the original mortar and reproduce the existing joint profile, so repaired areas blend into the rest of the elevation.

If brickwork is cracked as well as perished, repointing on its own will not hold — the crack will reopen through the new mortar. Where there is structural cracking we stabilise the wall first with HeliFix crack stitching, then repoint over the completed repair so the finished wall is both sound and unmarked.

The words get used interchangeably, but they are different jobs. Pointing is the finished outer face of the mortar joint. Repointing is raking out perished mortar and replacing it, which is the repair most Melbourne brick homes eventually need. Tuckpointing is a decorative finish, common on Victorian and Edwardian houses, where the joint is filled with a mortar coloured to match the brick and then a fine ribbon of white or black lime putty is laid over it to give the impression of very thin, precise joints. Restoring tuckpointing is specialist work in its own right; it is not the same as repointing a plain joint, and we will tell you which one your house has before quoting.

This is the decision that determines whether a repointing job protects a wall or damages it. Solid brick walls built up to roughly the 1930s were laid in lime mortar, which is soft, breathable and slightly flexible. Cavity brick from the post-war period onwards was laid in cement-based mortar, which is harder and less permeable. The rule is simple: the new mortar should never be harder than the bricks or the original mortar around it.

On period brickwork we use lime-based mixes, matched by strength and colour to the original. On post-war and modern brickwork we use an appropriately specified cement-lime mix. What we do not do is put a bagged high-strength mortar into a 1910 wall because it is quicker. That is the repointing that causes brick faces to spall a few winters later, and it is expensive to undo because the damaged bricks then need cutting out and replacing.

The shape of the finished joint changes how a wall looks and how it sheds water. Common Melbourne profiles are flush, weathered (sloped to throw water off), ironed or bucket-handle (a concave joint), raked (recessed) and struck. Raked joints look sharp but hold water on the ledge of the brick below and should not be used on exposed elevations. We reproduce the original profile so a repointed section reads as part of the wall, and we match the sand, which is what gives mortar most of its colour. A grey cement joint on a wall of cream lime mortar is visible from the street forever.

The parts of a house that get the most weather perish first. Chimneys, parapet walls and the top courses of front fences are exposed on several faces and often have failed capping or flashing on top, so water runs straight into the joints. Repointing these is worthwhile, but only after the capping is sorted, otherwise the new mortar is washed out the same way the old was. Chimney repointing frequently involves rebuilding the top few courses where the bricks have fretted, and we do that as part of the job.

Garden and boundary walls in Melbourne’s clay soils also move with the seasons, and repointing a wall that has cracked from footing movement will not hold. Where a wall is cracked as well as perished we stabilise it first with HeliFix crack stitching and then repoint.

Repointing is priced on the area to be done, the depth the joints have to be raked to, the access, and the mortar. A single fretted elevation at ground level with straightforward joints is at the low end. A two-storey period house with tuckpointing, a scaffold and a lime mortar matched to the original is a very different job. Repointing only the worst patches is usually a false economy on an old house, because the surrounding joints are at the same age and the patchwork shows.

We inspect the brickwork and give you a written quote at no charge. If some of the wall is sound and does not need doing, the quote says so.

Lime mortar joints properly raked and repointed will last for many decades; the original joints on most Melbourne period homes lasted the better part of a century. The failures we are asked to fix are almost always shallow smear repointing, where mortar was buttered over the old joint without raking it out and fell out within a few years, or hard cement over lime.

Repointing a small section of a garden wall is a reasonable weekend job for a careful owner. Repointing a house is not, mainly because of the raking-out (which damages brick edges if done with a grinder by an inexperienced hand), the mortar specification and the scaffold. If a section has been repointed badly in the past we can rake it out and do it again, but it costs more than doing it right the first time.

• How do I know if my brickwork needs repointing? Check the joints. If mortar crumbles when you press it, has eroded back more than a few millimetres from the brick face, has gaps or holes, or has moss growing in it, the wall needs repointing. Damp or salt staining on the inside of the same wall is another sign water is getting through the joints.
• What mortar should be used to repoint an old brick house? A lime-based mortar, matched in strength and colour to the original. Houses built up to about the 1930s were laid in lime mortar, and repointing them with hard cement mortar traps moisture and causes the brick faces to blow off. The new mortar should never be harder than the bricks.
• What is the difference between repointing and tuckpointing? Repointing replaces perished mortar in a plain joint. Tuckpointing is a decorative period finish where a fine ribbon of coloured lime putty is laid over a colour-matched joint to make the joints look very thin. Restoring tuckpointing is specialist work and is quoted separately.
• How deep should joints be raked out for repointing? To at least twice the width of the joint, and to sound mortar. Shallow surface pointing has nothing to key into and falls out. Raking out on soft period brick is done by hand or with care to avoid chipping the brick edges.
• Can you repoint a cracked brick wall? Repointing alone will not hold across a structural crack; the crack reopens through the new mortar. We stabilise the wall first with HeliFix crack stitching, then repoint over the completed repair so the finished wall is sound and the repair is invisible.
• How long does repointing take? A single elevation on a single-storey house is typically a few days. A whole period house with scaffold and lime mortar is usually one to two weeks depending on size and weather, because lime mortar needs protection while it cures.
• Will the repointed area match the rest of the wall? That is the aim of matching the sand, the mix and the joint profile to the original. Fresh mortar is lighter than weathered mortar for the first few months and blends in as it ages. On heritage homes we can prepare a sample joint for you to approve before starting.

We also carry out HeliFix crack stitching, lintel replacement, render crack repairs and concrete crack repairs.

• HeliFix crack stitching
• Leaking balcony repairs
• Render crack repairs
• Concrete crack repairs