Domakihub How to Repoint Brickwork and Make Joints Last
Restore crumbling mortar joints before water turns a cosmetic fault into a structural one.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Repointing — raking out deteriorated mortar and packing in fresh mix — is one of the most cost-effective repairs you can make to a masonry wall, yet it is also one of the easiest to get wrong. The video above walks through the hand-tool technique in detail; this article pairs those visuals with a clear method, the right mortar specification, and honest guidance on when to stop DIYing and call a licensed mason. For homes, holiday rentals, and hotels across Greece, where walls face intense summer UV, salt air, and freeze-thaw cycles at altitude, keeping mortar joints sealed is not optional maintenance — it is how you protect the structure itself.
Why Mortar Joints Fail
Portland-cement mortars are harder than the lime-based mixes traditionally used in Greek stone and brick construction. When a strong, rigid mortar is applied over older, softer masonry, thermal expansion cracks the joint rather than the pointing — which is exactly the right outcome. The problem arises when pointing is simply skipped for decades: water enters the open joint, wets the brick or stone behind it, and in winter the freeze-thaw cycle slowly levers the face off. On coastal properties salt crystallisation accelerates the same process.
Crazing, fine surface cracks, and hollow spots that ring when tapped are all signs pointing has lost adhesion. Crumbling or missing mortar to a depth of more than a few millimetres means water is already tracking into the wall cavity and repointing is urgent, not optional.
When You Need a Licensed Professional or a Building Permit
Straightforward repointing on a garden wall, boundary wall, or the non-structural external skin of a house is a legitimate DIY or small-contractor job in Greece. You do not ordinarily need a building permit for like-for-like mortar repair on an existing wall. However, three situations require a licensed civil engineer or structural contractor: (1) the wall is load-bearing and you find cracked or displaced bricks behind the joint, which indicates structural movement; (2) the property is listed or in a protected archaeological zone (common across the Greek islands and historic city centres), where any intervention on the façade may require a permit from the local Ephorate of Antiquities; (3) you suspect rising or penetrating damp behind the wall, where damp-proofing work in Greece must comply with building regulations and is best handled by a waterproofing specialist. If in doubt, have a mason inspect first — a one-hour site visit is cheap compared with the cost of repairing a wall you have inadvertently destabilised.
How to Repoint Brickwork: Step by Step
- 1
Rake out the old mortar to the correct depth
Using a plugging chisel and club hammer, or a purpose-made mortar raking disc on an angle grinder (with goggles and dust mask), cut back all loose, soft, or crumbling mortar to a minimum depth of 15–20 mm. The joint must be deep enough to give the new mortar a mechanical key. Shallow repairs — anything under 10 mm — will simply pop out within a season. Work systematically from top to bottom so debris does not contaminate joints you have already cleaned. Vacuum or brush out every joint before moving on.
- 2
Prepare and mix the mortar to the right specification
Matching the mortar strength to the masonry is critical. For older brick or soft limestone (common in the Cyclades and the Ionian islands), use a lime-based mix: one part hydraulic lime (NHL 3.5 or NHL 5) to three parts sharp sand. For harder engineering brick or concrete block, a 1:1:6 cement-lime-sand mix is appropriate. Never use a straight ordinary Portland cement mix on traditional masonry — it is too rigid and will crack the bricks rather than the joint. Mix only as much as you can use in 30–45 minutes. In summer in Greece, work in the shade or in the cool of the morning; direct sun dries the mix too fast and weakens the bond.
- 3
Dampen the joints and pack in the new mortar
Mist the raked joints with clean water from a spray bottle. Damp masonry gives the mortar time to cure slowly (hydration) rather than having its water sucked out by dry brick. Load mortar onto a hawk and use a narrow pointing trowel (6–10 mm) to press the mix firmly into the joint in two or three thin layers rather than one thick application. Push each layer hard against the back of the joint to eliminate voids. Fill the perpendicular (vertical) joints first, then the bed (horizontal) joints. Overfill slightly — you will shape the face in the next step.
- 4
Profile the joint finish to match the existing wall
Once the mortar has firmed up to a 'thumbprint' consistency — firm but not hard, usually 20–40 minutes depending on temperature — shape the joint profile to match the surrounding wall. The most common finish in Greek construction is a flush or slightly recessed joint, which sheds water well. A weather-struck joint (angled so rain runs off the lower brick face) offers even better drainage. Avoid a raked joint (deeply recessed) on exterior walls in wet climates or exposed coastal sites, as it traps water. Use a jointing iron, a piece of copper pipe, or the edge of a trowel to compress and profile the surface.
- 5
Cure, clean off, and inspect after 48 hours
Protect fresh pointing from direct sun and wind for at least 48 hours by hanging hessian sacking or a breathable tarpaulin over the wall — do not use polythene, which traps condensation. In hot Greek summer conditions, lightly re-mist the joints morning and evening for the first two days. Once fully cured (7 days for lime mixes), brush off any mortar smears with a stiff-bristle brush. Do not use acid-based brick cleaners on lime-pointed walls as they will dissolve the new mortar. Final inspection: tap each joint with a coin — a hollow sound means poor adhesion and the patch must be raked out and redone.
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FAQ
- How do I know if my mortar joints need repointing or the whole wall needs rebuilding?
- Probe the joint with a screwdriver. If mortar is soft and crumbles more than 20 mm deep on a significant portion of the wall, the issue is chronic water ingress rather than surface erosion, and you should have a structural mason assess whether individual bricks or stones have been damaged. Spalling brick faces (where the outer layer has flaked off) or horizontal cracks following the bed joints are signs the wall has moved and repointing alone will not fix it.
- What type of mortar should I use for a traditional Greek stone house?
- Traditional Cycladic, Ionian, or mainland rural stone walls were built with weak lime-sand mortars, sometimes with an added pozzolanic material (natural volcanic ash, which is abundant in Santorini). The correct modern equivalent is NHL 3.5 hydraulic lime mixed 1:2.5 or 1:3 with sharp sand. Using standard Portland cement in these walls is one of the most common and costly mistakes — it traps moisture behind an impermeable face and accelerates spalling of the soft stone.
- Can I repoint in winter or does the mortar need warm weather?
- In Greece, winter repointing is possible in many regions but requires care. Lime and cement mortars must not freeze within 24 hours of application. Avoid work when overnight temperatures are forecast below 5 °C, and never apply mortar to frozen or frost-covered masonry. The ideal working temperature range is 8–25 °C. For winter jobs in mountain areas or at altitude, use an NHL 5 hydraulic lime (faster set) and protect the wall overnight with insulated blankets.