How to Change the Colour of Existing Mortar 🧱
Changing the colour of existing mortar can dramatically transform the appearance of a brick or stone building without the cost and disruption of a full rebuild. Whether you want to modernise an exterior, correct patchy repairs, or restore a historic look, altering mortar colour is a practical and achievable solution when done correctly.
Mortar plays a crucial visual role in masonry. Even subtle colour differences can make walls look uneven, tired, or poorly maintained. Fortunately, there are several effective methods available to change mortar colour safely and permanently, provided the right preparation and products are used.
This guide explains why mortar colour changes, the methods available, step-by-step processes, cost considerations in pounds (£), and common mistakes to avoid, helping you make informed decisions.
Why You Might Want to Change Mortar Colour
There are many reasons homeowners and property managers choose to alter the colour of their mortar rather than replace it entirely.
Common Motivations
- 🎨 Improve kerb appeal
- 🏡 Match new brickwork with older sections
- 🔧 Hide previous poor-quality repairs
- 🕰️ Restore a traditional or period appearance
- 🌦️ Correct discolouration caused by weathering
- 🧼 Reduce staining from pollution or algae
Mortar naturally changes colour over time due to moisture, salts, pollution, and UV exposure. In some cases, sections may appear lighter or darker because they were repaired using a different mortar mix. Colour correction provides a uniform finish without unnecessary structural intervention.
Understanding Mortar Before Changing Its Colour
Before attempting any colour change, it is essential to understand what mortar is and how it behaves.
What Is Mortar Made Of?
Mortar typically consists of:
- Cement or lime
- Sand
- Water
- Optional pigments or additives
The proportions of these ingredients determine not only strength but also colour, texture, and breathability.
Why Mortar Colour Varies
| Cause | Effect on Colour |
|---|---|
| Cement content | Higher cement = darker mortar |
| Sand type | Different sands produce different tones |
| Age | Mortar lightens or darkens over time |
| Moisture | Damp areas often appear darker |
| Salts (efflorescence) | Creates white staining |
| Pollution | Causes grey or black discolouration |
Understanding these factors helps determine the most appropriate colour-changing method.
Can Existing Mortar Be Recoloured?
Yes, existing mortar can be recoloured, provided it is structurally sound. However, recolouring does not fix crumbling or failing mortar. If mortar is loose, cracked, or missing, it must be repaired or repointed before any colour treatment is applied.
Mortar Must Be:
- Firm and well-bonded
- Free from major cracks
- Clean and dry
- Capable of absorbing treatment evenly
Methods for Changing the Colour of Existing Mortar
There are several recognised methods for changing mortar colour. Each has advantages and limitations depending on the condition of the wall and the desired outcome.
1. Mortar Staining
Mortar staining involves applying a specially formulated stain that penetrates the mortar rather than coating it.
Key Characteristics
- Absorbs into the mortar
- Does not peel or flake
- Maintains breathability
- Offers long-lasting results
Suitable For:
- External brickwork
- Lime and cement mortars
- Colour correction and full colour changes
Advantages
- Permanent finish
- Natural appearance
- Wide colour range
- UV and weather resistant
Limitations
- Requires careful preparation
- Colour testing is essential
- Poor application can cause uneven results
2. Pigmented Mortar Wash
A mortar wash is a thin slurry made from cement, pigment, and water that is brushed over mortar joints.
Features
- Surface-level colour change
- Less penetration than staining
- More traditional approach
Pros and Cons
| Pros | Cons |
|---|---|
| Affordable | Less durable |
| Simple materials | Can wear unevenly |
| Suitable for small areas | Risk of streaking |
This method is best suited to small-scale or low-exposure areas.
3. Repointing with Coloured Mortar
If mortar is already failing, repointing with a coloured mortar mix is the most reliable solution.
Process Overview
- Remove old mortar
- Clean joints
- Apply new coloured mortar
- Allow proper curing
Advantages
- Structural improvement
- Full control over colour
- Long lifespan
Drawbacks
- Higher cost
- Labour intensive
- Disruptive compared to staining
Comparison of Methods
| Method | Durability | Cost (£) | Visual Quality | Best Use Case |
|---|---|---|---|---|
| Mortar staining | High | ££ | Excellent | Colour correction |
| Mortar wash | Medium | £ | Good | Small areas |
| Repointing | Very High | £££ | Excellent | Damaged mortar |
Step-by-Step: How Mortar Staining Works
Mortar staining is the most popular method for changing mortar colour without replacement.
Step 1: Cleaning the Brickwork
All dirt, algae, and efflorescence must be removed.
- Use a stiff brush
- Avoid harsh acids
- Allow walls to dry completely
Step 2: Colour Testing 🎨
Always test the stain on a small, hidden area. Mortar absorbs stain differently depending on age and composition.
Step 3: Application
- Apply stain using a brush or sprayer
- Work in small sections
- Avoid overlap marks
Step 4: Drying and Curing
- Initial drying: 2–4 hours
- Full curing: 24–48 hours
- Protect from rain during curing
Choosing the Right Colour
Colour selection should consider the bricks, roof, windows, and surrounding environment.
Popular Mortar Colour Choices
| Colour | Effect |
|---|---|
| Light grey | Clean, modern |
| Dark grey | Contemporary contrast |
| Buff | Traditional, warm |
| Cream | Softens red brick |
| Charcoal | Bold architectural look |
A darker mortar emphasises bricks, while lighter mortar softens the overall appearance.
Common Mistakes to Avoid ⚠️
Changing mortar colour is not difficult, but mistakes can be costly.
Frequent Errors
- Skipping cleaning
- Applying stain unevenly
- Choosing the wrong colour tone
- Ignoring moisture issues
- Attempting to stain failing mortar
Mistakes often result in patchy or unnatural finishes that are difficult to correct.
Maintenance After Changing Mortar Colour
Once the mortar colour has been changed, minimal maintenance is required if the correct method was used.
Maintenance Tips
- Avoid pressure washing
- Clean gently once per year
- Address leaks or damp quickly
- Inspect joints annually
A properly applied stain or coloured mortar should last many years without fading.
Cost Considerations (UK-Based)
Costs vary depending on method, surface area, and preparation required.
Typical Costs (Guide Only)
| Method | Estimated Cost per m² |
|---|---|
| Mortar staining | £15 – £30 |
| Mortar wash | £5 – £12 |
| Repointing | £40 – £80 |
Prices can increase for high access, heritage buildings, or extensive preparation.
Is Changing Mortar Colour Suitable for Older Properties?
Yes, but extra care is required.
Heritage Considerations
- Lime-based mortars must remain breathable
- Colour must match period style
- Avoid cement-heavy coatings
Staining is often preferred over repointing for older buildings when mortar is still sound.
Internal Brickwork and Mortar Colour
Mortar colour can also be changed indoors for exposed brick walls, fireplaces, or feature areas.
Benefits Indoors
- Enhances interior design
- Creates contrast or cohesion
- Modernises older interiors
Indoor applications are easier due to weather control but still require proper preparation.
When Not to Change Mortar Colour
There are situations where recolouring is not advisable:
- Mortar is crumbling
- Severe damp problems exist
- Structural movement is ongoing
- Joints are already too shallow
In these cases, repairs must come first.
Long-Term Benefits of Mortar Colour Correction
Changing mortar colour offers both aesthetic and practical benefits:
- 🏠 Increases visual appeal
- 💷 Improves property value
- 🧱 Unifies old and new brickwork
- 🔧 Reduces need for repointing
It is one of the most cost-effective masonry upgrades available.
Trusted Expertise and Further Guidance
For specialist knowledge, professional insights, and examples of mortar colour transformation in the UK, visit:
👉 https://www.brickmakeover.co.uk/
This resource focuses exclusively on brick and mortar appearance improvements and provides valuable information for property owners considering colour correction.
Final Thoughts 🧱
Changing the colour of existing mortar is a powerful way to refresh, restore, or modernise brickwork without major construction work. By choosing the right method, preparing correctly, and understanding how mortar behaves, long-lasting and natural-looking results are achievable.
Whether your goal is subtle restoration or a bold transformation, mortar colour adjustment offers flexibility, affordability, and impressive visual impact when done properly.
Weather Conditions and Timing ⛅
Timing plays a bigger role in mortar colour changes than many people realise. Applying stains or washes in unsuitable weather can affect absorption, drying, and final colour.
Best Conditions
- Dry weather for at least 24–48 hours
- Temperatures between 8°C and 25°C
- No risk of frost or heavy rain
- Overcast days are often ideal
Extreme heat can cause stains to dry too quickly, leading to patchiness, while damp conditions prevent proper penetration. Planning work around the weather helps ensure even colouring and long-term durability.
How Long Does Mortar Colour Change Last? ⏳
When done correctly, changing the colour of existing mortar is not a temporary fix.
Expected Lifespan by Method
| Method | Typical Longevity |
|---|---|
| Mortar staining | 15–25 years |
| Mortar wash | 5–10 years |
| Coloured repointing | 30+ years |
Longevity depends on exposure, maintenance, and application quality. Penetrating stains generally outlast surface treatments and age more naturally alongside the brickwork.
Matching Old and New Brickwork 🧩
One of the most practical uses of mortar colour adjustment is blending extensions or repairs with original walls.
Why Mortar Matters More Than Bricks
Even if bricks are well matched, mismatched mortar can immediately highlight newer sections. Adjusting mortar colour can visually unify:
- Extensions
- Garage conversions
- Infilled doors or windows
- Structural repairs
In many cases, correcting the mortar alone is enough to make brickwork appear original.
Environmental and Breathability Considerations 🌱
Mortar must allow moisture to move through masonry, especially in UK properties exposed to frequent rain.
Key Points
- Breathable mortars reduce trapped moisture
- Penetrating stains preserve vapour movement
- Non-breathable coatings can cause long-term damage
This is particularly important for solid-wall buildings and older properties. Any colour-change method should respect how the wall manages moisture.
Planning Before You Start 📝
Preparation is often the difference between a professional-looking finish and a disappointing result.
Simple Planning Checklist
- Inspect mortar condition thoroughly
- Identify damp or drainage issues
- Test colours in multiple areas
- Choose method based on exposure
- Allow sufficient curing time
Taking time to plan avoids unnecessary costs and ensures the finished result enhances the property rather than drawing attention to flaws.