Repointing Brickwork: Costs, Methods, and DIY Tips
How much does repointing cost? Cement vs lime mortar, when to repoint, costs per square metre, and whether to DIY or hire a professional.
Mortar joints are the unsung heroes of your home's weatherproofing. They shed rainwater, accommodate thermal movement, and keep draughts out. But mortar doesn't last forever - and when it fails, penetrating damp, brick damage, and heat loss follow.
Repointing is one of the most cost-effective external repairs you can make. Here's how to get it right.
When Does Brickwork Need Repointing?
The Finger Test
Run your finger firmly across the mortar joints. Healthy mortar is hard and flush with (or slightly recessed from) the brick face. Mortar that needs attention:
- Crumbles when touched - mortar has lost its binder
- Recessed more than 5mm - weathering has eroded the face
- Missing entirely - gaps visible between bricks
- Cracks running through joints - settlement or thermal movement
- Soft and sandy - mortar scrapes out easily with a key or screwdriver
Other Warning Signs
- Damp patches on internal walls, especially after driving rain
- Mortar dust or fragments on window sills and at wall bases
- Green algae or moss growing in open joints (holds moisture against the bricks)
- Bricks starting to spall (face flaking off) - often caused by hard cement mortar trapping moisture in softer bricks
Mortar Choice: The Critical Decision
Getting the mortar right is more important than the repointing technique. The wrong mortar causes more damage than no repointing at all.
Lime Mortar (Pre-1919 Buildings)
Houses built before 1919 were constructed with lime mortar - a softer, more flexible mix that allows moisture to evaporate through the joints. The bricks in these buildings are often relatively soft (stock bricks, handmade bricks).
Why lime matters: Lime mortar is softer than the bricks. When moisture enters the wall (and it always does), it migrates to the softest material - the mortar - and evaporates harmlessly. If you replace lime mortar with hard cement mortar, moisture is forced through the bricks instead, causing them to spall, crack, and deteriorate.
- Mix: NHL (Natural Hydraulic Lime) 3.5 or NHL 5, mixed with sharp sand (typically 1:2.5 or 1:3)
- Cost: £40–£80 per m² (material and labour)
- Curing: Slower than cement - needs protection from frost and rain for 3–7 days
- Appearance: Softer, slightly textured finish that mellows with age
The RICS and Historic England both recommend lime mortar for pre-1919 buildings. Using cement on a listed building is almost certainly a condition breach.
Cement Mortar (Post-1930 Buildings)
Modern houses (post-1930) use harder engineering bricks and were designed for cement mortar. A standard mix works well:
- Mix: OPC (Ordinary Portland Cement) with lime and sand (1:1:6 or 1:2:9)
- Cost: £30–£60 per m²
- Curing: Sets within 24 hours, full strength in 7 days
- Appearance: Harder, more uniform finish
The Danger Zone: 1919–1930
Houses from this era may have softer bricks with cement mortar, or harder bricks with lime mortar. Check the existing mortar - if it's lime-based, replace with lime. If cement, use cement. When in doubt, choose lime - it's compatible with all brick types.
Costs in Detail
Per Square Metre
| Work | Cement Mortar | Lime Mortar |
|---|---|---|
| Repointing (flush or bucket handle) | £30–£50/m² | £40–£70/m² |
| Repointing (recessed or weather-struck) | £35–£60/m² | £50–£80/m² |
| Raking out only (if separate) | £10–£20/m² | £10–£20/m² |
By Property Type
| Property | Wall Area (approx.) | Cement Repoint | Lime Repoint |
|---|---|---|---|
| Mid-terrace (front only) | 20–30m² | £800–£1,500 | £1,000–£2,000 |
| Semi-detached (3 elevations) | 50–70m² | £2,000–£4,000 | £2,500–£5,000 |
| Detached (all sides) | 80–120m² | £3,000–£6,500 | £4,000–£9,000 |
| Chimney stack | 3–6m² | £300–£600 | £400–£800 |
Additional Costs
| Item | Cost |
|---|---|
| Scaffolding (2-storey, single elevation) | £400–£800 |
| Scaffolding (full house) | £1,000–£2,500 |
| Brick replacement (spalled bricks) | £5–£15 per brick |
| Brick cleaning (after repointing) | £5–£15/m² |
| Conservation-grade lime mortar (listed buildings) | +20–30% on lime prices |
Scaffolding tip: If you're also having roof work, gutter repairs, or window replacement done, coordinate with repointing to share scaffolding costs.
The Repointing Process
Step 1: Raking Out
Old mortar is removed to a depth of 15–20mm using a mortar rake, plugging chisel, or carefully controlled angle grinder. This creates enough depth for the new mortar to key properly.
Important: Never use a disc cutter (angle grinder) carelessly - it's easy to damage brick edges, especially on soft stock bricks. Hand raking is slower but safer, particularly on pre-1919 buildings.
Step 2: Cleaning and Wetting
Dust and debris are brushed or blown from the joints. The joints are dampened with water before mortar is applied - this prevents the dry bricks from sucking moisture out of the new mortar too quickly, which causes cracking.
Step 3: Applying New Mortar
Fresh mortar is pressed firmly into the joints using a pointing trowel, working in layers if the joints are deep. The mortar must be pushed into full contact with both the top and bottom brick - voids behind the mortar face will trap water.
Step 4: Finishing the Joint
The joint profile is tooled to match the original:
| Profile | Description | Best For |
|---|---|---|
| Flush | Level with brick face | Most common, good weathering |
| Bucket handle | Slightly concave curve | Popular, neat appearance, good drainage |
| Weather-struck | Angled to shed water downward | Best for exposed elevations |
| Recessed | Set back from brick face | Shows brick edges, period look, less weather-resistant |
Step 5: Protection
Fresh lime mortar needs protecting from rain and frost for 3–7 days - typically with hessian or damp sheeting. Cement mortar is less sensitive but should still be protected from heavy rain for 24 hours.
DIY vs Professional
DIY Repointing
Feasible for: Small areas at ground level (under 10m²), garden walls, low-risk areas.
You'll need:
- Mortar rake or plugging chisel (£5–£15)
- Pointing trowel (£8–£15)
- Mortar (pre-mixed bags from B&Q or Wickes: £5–£10 per 10kg bag)
- Bucket, hawk, brush, spray bottle
- Safety glasses and dust mask
Cost: £2–£5 per m² in materials (vs £30–£80 for professional).
Caution: Poor repointing is instantly visible and very difficult to correct. If you're not confident in achieving a consistent joint finish, hire a professional - find a TrustMark-registered bricklayer.
Professional Repointing
Hire a professional for: Full-house repointing, anything above ground floor, lime mortar work, listed buildings, decorative brickwork.
What to look for:
- Experience with your mortar type (lime vs cement)
- Examples of completed work on similar properties
- Understanding of joint profiles and brick types
- TrustMark registration or trade body membership
Get 3 quotes - see our guide to builder quotes. Ask each contractor what mortar mix they'll use and why.
Repointing and Damp
Failed mortar is one of the main causes of penetrating damp. If you have damp patches on internal walls that worsen during rain:
- Check the external mortar on the corresponding wall
- Check gutters and downpipes - overflowing gutters saturate brickwork from above
- Check chimney pointing - chimney stacks are the most exposed masonry on the house
- Repoint the affected area and monitor for 3–6 months
If damp persists after repointing, the cause may be rising damp, condensation, or a hidden defect. Get a professional damp survey.
Next Steps
- Inspect your mortar joints - use the finger test on each elevation
- Identify your mortar type - lime (pre-1919) or cement (post-1930)
- Get 3 quotes - specify the mortar type and joint profile you want
- Coordinate with other external work - share scaffolding with roof, gutter, or window work
- Get a repair estimate - use our repair calculator for costs in your area
- Check our glossary for terms like pointing, mortar, spalling, and NHL lime
Frequently Asked Questions
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