How deep do you rake out mortar joints when repointing brickwork?

Mortar joints must be raked out to a depth of 15 to 20 mm, or approximately twice the joint width, to provide adequate mechanical keying for new mortar. Raking too shallow causes premature adhesion failure. A raking iron, plugging chisel, or diamond raking blade connected to an M-class vacuum should be used to protect the brick edges.

What mortar mix ratio should be used for repointing Australian brick walls?

Standard modern brickwork requires an M3 mortar mix consisting of 1 part cement, 1 part lime, and 6 parts washed brickies sand by volume. For heritage lime mortar or soft clay bricks, use a weaker mix of 1 part lime to 3 parts sand to avoid trapping moisture or spalling brick faces.

What Australian standards govern brickwork repointing?

Brick repointing and masonry repairs in Australia are governed by AS 3700:2018 (Masonry structures) and AS 4773.1 (Masonry in small buildings). These standards define mortar class durability, structural load requirements, and compatibility between masonry units and mortar types to meet National Construction Code (NCC) performance requirements.

What are the regulatory safety requirements for cutting out mortar joints in Australia?

Dry cutting mortar generates respirable crystalline silica (RCS), strictly regulated under SafeWork Australia national workplace exposure standards. Tradies must use an on-tool extraction system fitted to an M-class or H-class dust extractor, alongside a fit-tested P2 or P3 respirator, eye protection, and heavy-duty nitrile-coated gloves.

Why is dampening the joints necessary before applying repointing mortar?

Dampening joints with clean water prevents dry, porous bricks from sucking moisture out of fresh mortar before hydration finishes. If bricks draw away the mixing water too rapidly, the mortar cures weak, turns powdery, and shrinks away from the bedding plane, causing hairline cracking and water ingress.

How long does new mortar need to cure before finishing or weather exposure?

Repointed mortar typically reaches initial set within 1 to 2 hours, at which point it should be profiled with a pointing iron. Protect the wall from direct rain and extreme drying conditions for at least 48 to 72 hours using damp hessian or polythene sheeting to allow full hydration.

How to repoint brickwork on an exterior wall

Learn how to repoint exterior brickwork to stop moisture ingress and restore structural integrity. Follow Australian standards for mortar mixes and raking.

Quick answer

Repointing an exterior brick wall involves raking out decayed mortar to a depth of 15 to 20 millimetres, dampening the joint, and packing in a compatible cement-lime-sand mix. Mortar must be finished with a jointing iron before curing to ensure a weather-tight seal compliant with AS 3700 standards.

Skill level: Intermediate
Time: 1–2 days for a small wall area of around 5–10 m²
Trade: Building & Construction
Updated: 1 November 2026

Tools you will need

Makita 125mm SJSII Angle Grinder with Mortar Raking Shroud
Mirka or Festool M-Class Dust Extractor
Marshalltown 100mm Tuck Pointer / Pointing Trowel
Footprint Mortar Raking Chisel
Boral Brickies Sand & Dingo General Purpose Cement (or Bastard Lime)
Spear & Jackson Brick Jointer / Pointing Iron
Stiff Bristle Churn Brush
Tradecorp Steel Hawk (Mortar Board)

🧱 Repointing exterior brickwork restores weathered mortar joints, improves weather resistance, and helps prevent moisture entry into older brick walls. Done properly, it can extend the life of the wall and improve appearance, but the key is removing failed mortar carefully and packing in compatible new mortar without damaging the bricks.

What is involved in repointing exterior brickwork in Australia?

Repointing brickwork means removing loose or deteriorated mortar from the joints and replacing it with fresh mortar to restore strength, weather resistance, and appearance. For Australian homes, this is particularly important before winter or when renovating older brick façades where cracked joints can allow moisture ingress.

This guide covers a practical DIY method for small-to-medium exterior wall areas. If the wall is leaning, heavily cracked, bulging, or loadbearing with signs of movement, get a structural assessment first, as repairs may require an engineer and a licensed bricklayer under relevant state requirements.

What skill level is required for repointing brickwork on an exterior wall?

Intermediate — Estimated time: 1–2 days for a small wall area of around 5–10 m²

What tools are essential for repointing exterior brickwork in Australia?

Brick bolster and club hammer for controlled mortar removal

Joint raker or plugging chisel for clearing mortar joints to 15–20 mm depth

Angle grinder with 100–125 mm diamond mortar raking blade and dust shroud for larger areas

Pointing trowel, narrow tuck pointer, and small brick trowel

Stiff nylon or masonry brush

Bucket or mixing tub, plus measuring bucket for mortar ratios

Hawk or mortar board

Spray bottle or garden sprayer for dampening joints

Sponge and clean rags for light cleanup

Ladder or compliant mobile scaffold for higher work areas

PPE: safety glasses, P2 dust mask, hearing protection, gloves, long sleeves

What materials are needed for repointing exterior brickwork?

Mortar mix matched to existing wall type and age

For general repointing, a mortar such as 1:1:6 cement:lime:sand or a pre-blended repointing mortar suitable for masonry

Washed brick sand or sand matched in colour and grading to existing mortar

Clean water

Masonry cleaner or diluted brick cleaning solution if needed after curing

Masking materials or drop sheets to protect paths, windows, and garden beds

Optional mortar oxide, only if colour matching is required

Replacement bricks if any are cracked, loose, or severely damaged

Safety Requirements

Wear safety glasses, gloves, long sleeves, and a P2 dust mask when raking out joints.

Use hearing protection if using an angle grinder.

Check wall stability before starting. Loose bricks or movement may indicate structural issues requiring professional advice.

Use ladders safely and avoid overreaching. For sustained work above shoulder height, a properly erected scaffold is safer.

Manage silica dust carefully when grinding mortar. Wet down where appropriate and use dust extraction.

Manual handling matters: mortar, tools, and scaffold components can be heavy.

For structural masonry, repairs should align with AS 3700 and major defects should be assessed before cosmetic repointing.

If the wall includes flashings, weepholes, or adjacent waterproofed areas, do not block drainage paths. Internal wet areas are governed by AS 3740, though exterior repointing itself is not a substitute for full waterproofing design.

Step-by-Step Guide

Step 1: Inspect the wall and confirm repointing is suitable

Check whether the problem is limited to the mortar joints or whether there are bigger issues such as stepped cracking, bowing, salt attack, rusting lintels, or loose bricks. Repointing is suitable where mortar is weathered, powdery, missing, or cracked, but the bricks themselves are still largely sound.

Tap around the wall and mark joints that need work. If more than a few bricks are loose, the wall has significant movement, or cracks continue through bricks rather than only the mortar, pause and seek professional advice.

💡 For older homes, the original mortar may be softer and lime-rich. New mortar should usually be similar or slightly softer than the existing mortar, not harder, so the bricks remain protected.

Step 2: Match the mortar before you start

The new mortar should match the existing mortar in strength, colour, texture, and finish as closely as possible. Older Australian brick homes often used softer lime-based mortars, while newer work may use cement-lime-sand blends.

A good general repointing mix for many exterior walls is 1:1:6 cement:lime:sand. Avoid overly strong mortar such as 1:1.5:2.5 unless specified for structural work, because mortar that is too hard can trap moisture and cause brick faces to spall.

If in doubt, take a sample to a masonry supplier and ask for a compatible repointing blend. Pre-bagged heritage or restoration mortars can be a good option for DIY users.

Step 3: Prepare the area

Protect nearby paving, windows, plants, and downpipes with drop sheets. Remove any loose paint flakes, dirt, or surface debris from the wall.

If you're working in hot, dry, or windy weather, plan to work in shaded sections. Mortar can dry too quickly in Australian conditions, reducing bond strength and increasing shrinkage cracking.

Set up safe access. For anything beyond low-level patch repairs, scaffold is often more efficient and safer than repeated ladder work.

Step 4: Rake out the old mortar

Remove defective mortar to a minimum depth of 15 mm, or about 2 times the width of the joint, whichever is greater. The goal is to reach solid mortar while keeping brick edges intact.

Use a plugging chisel or joint raker for softer mortar and heritage work. For larger areas, an angle grinder can speed things up, but it must be used carefully to avoid widening joints or chipping bricks.

Work the bed joints first, then the perps (vertical joints). Do not rake out too much wall at once if weather may change.

💡 Hand tools are slower but often safer on older, softer bricks. Grinder use is best reserved for straight joints in harder brickwork.

Step 5: Clean out the joints thoroughly

Brush out all loose mortar, grit, and dust from the joints using a stiff brush. If necessary, blow out fine dust or vacuum it away.

Clean joints are critical. New mortar will not bond properly to dusty or crumbly surfaces. Avoid leaving polished grinder dust packed into the back of the joint.

The joint should be open, square, and free of loose material, ready to receive fresh mortar.

Step 6: Dampen the brickwork

Lightly mist the wall and joints with clean water before pointing. The bricks and old mortar should be damp, not dripping wet.

This step is especially important in warm or windy Australian conditions. Dry brickwork can suck moisture out of fresh mortar too quickly, weakening the bond and causing the mortar to crack or crumble.

Re-wet as needed while working, particularly with porous older bricks.

Step 7: Mix the new mortar

Mix only small batches that can be used within a workable period. For many exterior repointing jobs, use a compatible mix such as 1:1:6 cement:lime:sand, or a quality pre-blended repointing mortar.

Add water gradually until the mortar is firm, cohesive, and workable. It should hold on the trowel without slumping. Mortar that is too wet will stain the brick face, shrink more, and be harder to compact into the joints.

For general-purpose masonry work, common site mixes include 1:2:3 and for structural concrete 1:1.5:2.5, but for brick repointing you should prioritise compatibility with the original mortar rather than using a stronger generic mix.

Step 8: Pack the mortar into the joints

Using a pointing trowel or tuck pointer, press mortar firmly into the joints in layers if the joint is deep. Compact it tightly against the back and sides of the joint to eliminate voids.

Fill the vertical joints first, then the horizontal joints, or follow a consistent method that keeps the work neat. Slightly overfill the joints initially.

Do small sections at a time, especially as you learn the set time. Good compaction matters more than speed.

Step 9: Tool and finish the joints

Let the mortar firm up until thumbprint hard, then tool it to match the existing profile. Common finishes include flush, slightly recessed, or weather-struck joints. Match the original wall style wherever possible.

Use a jointing tool or trowel to compress the mortar surface. This improves weather resistance and gives a more professional finish.

Brush off crumbs only after the mortar has stiffened enough not to smear. Avoid wiping wet mortar across the brick face.

Step 10: Cure and protect the work

Fresh mortar needs controlled curing. Protect the wall from direct sun, strong wind, and rain for at least 24–72 hours depending on conditions.

Lightly mist the work if conditions are hot and dry, particularly during the first day. Do not saturate the wall.

If rain is expected, cover the area with breathable protection that does not sit hard against the fresh joints.

Step 11: Clean up the brick face

Once the mortar has cured sufficiently, brush the wall down to remove loose residue. If minor smears remain, clean them gently using a brick-safe masonry cleaner suitable for the brick type.

Avoid aggressive acid washing on fresh mortar or old bricks. Acid can damage mortar joints and discolour masonry if used incorrectly.

For stubborn staining or efflorescence, wait until the mortar has cured properly and follow the product instructions closely.

Step 12: Check the finished result

Inspect the wall for any missed joints, shrinkage cracks, or areas where the mortar has pulled back. Touch up minor defects promptly while the colour match is still fresh.

Make sure weepholes remain open and that no mortar has bridged expansion joints, vents, or drainage points. The finished joints should be full, compacted, and consistent in profile.

Common Mistakes to Avoid

1.Using mortar that is too hard for the existing brickwork, which can cause brick faces to crack or spall.

2.Raking out joints too shallow, usually less than 15 mm, leading to poor bond and early failure.

3.Smearing wet mortar over the brick face and creating staining that is difficult to remove.

4.Skipping dampening in hot weather, causing the mortar to dry too quickly and crack.

5.Repointing over structural cracks or loose brickwork without first addressing the underlying cause.

Pro Tips

💡 Test your mortar colour on a small hidden section first. Mortar often dries lighter than it looks when wet.

💡 Work in manageable areas of around 0.5–1 m² so you can tool the joints at the right time.

💡 If the house is older than about 1950s, investigate whether a lime-rich mortar is more appropriate than a cement-heavy mix.

💡 Hire a mortar rake grinder and small mobile scaffold for larger jobs rather than buying them outright. Hire usually makes better economic sense for one-off repointing projects.

💡 Keep a few sample photos of the original joint profile before starting so the repaired areas blend with the rest of the wall.

Recommended Tools

Arbortech AS170 Brick and Mortar Saw — excellent for controlled joint removal with less brick damage

125 mm angle grinder with mortar raking blade and dust shroud — efficient for larger repointing areas

Marshalltown pointing trowel set — good control for packing narrow joints

Ox Pro jointing tools — useful for matching common joint profiles neatly

Bailey platform ladder or mobile aluminium scaffold — safer and faster than constant ladder repositioning for wall work

Frequently asked questions

How deep do you rake out mortar joints when repointing brickwork?: Mortar joints must be raked out to a depth of 15 to 20 mm, or approximately twice the joint width, to provide adequate mechanical keying for new mortar. Raking too shallow causes premature adhesion failure. A raking iron, plugging chisel, or diamond raking blade connected to an M-class vacuum should be used to protect the brick edges.
What mortar mix ratio should be used for repointing Australian brick walls?: Standard modern brickwork requires an M3 mortar mix consisting of 1 part cement, 1 part lime, and 6 parts washed brickies sand by volume. For heritage lime mortar or soft clay bricks, use a weaker mix of 1 part lime to 3 parts sand to avoid trapping moisture or spalling brick faces.
What Australian standards govern brickwork repointing?: Brick repointing and masonry repairs in Australia are governed by AS 3700:2018 (Masonry structures) and AS 4773.1 (Masonry in small buildings). These standards define mortar class durability, structural load requirements, and compatibility between masonry units and mortar types to meet National Construction Code (NCC) performance requirements.
What are the regulatory safety requirements for cutting out mortar joints in Australia?: Dry cutting mortar generates respirable crystalline silica (RCS), strictly regulated under SafeWork Australia national workplace exposure standards. Tradies must use an on-tool extraction system fitted to an M-class or H-class dust extractor, alongside a fit-tested P2 or P3 respirator, eye protection, and heavy-duty nitrile-coated gloves.
Why is dampening the joints necessary before applying repointing mortar?: Dampening joints with clean water prevents dry, porous bricks from sucking moisture out of fresh mortar before hydration finishes. If bricks draw away the mixing water too rapidly, the mortar cures weak, turns powdery, and shrinks away from the bedding plane, causing hairline cracking and water ingress.
How long does new mortar need to cure before finishing or weather exposure?: Repointed mortar typically reaches initial set within 1 to 2 hours, at which point it should be profiled with a pointing iron. Protect the wall from direct rain and extreme drying conditions for at least 48 to 72 hours using damp hessian or polythene sheeting to allow full hydration.

Written by Bricko, the Building & Construction specialist at QLD.Tools.