The £7,000 Question: Clean or Replace Your Render?
If your Birmingham property's render is looking tired, stained, or discoloured, you're facing a decision that could cost anywhere from £400 to £8,000 or more. Should you invest in professional render cleaning, or is it time for complete re-rendering? For most West Midlands property owners, the answer isn't immediately obvious—but understanding the true costs and benefits of each option makes the decision much clearer.
This comprehensive cost comparison will help you make the right choice for your property and your budget.
Understanding the Problem: What's Wrong with Your Render?
Before comparing costs, it's essential to understand what you're dealing with:
Cosmetic Issues (Cleaning Can Fix)
- Biological growth - Algae, moss, lichen creating black, green, or brown staining
- Atmospheric pollution - Carbon deposits and environmental grime
- General discolouration - Render appearing darker or patchy
- Surface contamination - Dirt and organic matter accumulation
Key indicator: The render surface itself is sound—it's just dirty or contaminated.
Structural Issues (Replacement Required)
- Cracking - Significant cracks allowing water penetration
- Delamination - Render separating from substrate
- Blown render - Hollow-sounding areas indicating detachment
- Severe erosion - Render worn away exposing substrate
- Damp penetration - Water entering through failed render
Key indicator: The render structure is compromised, not just dirty.
The True Cost of Professional Render Cleaning
Birmingham Area Pricing
Typical semi-detached house (100-150m² render area):
- Professional cleaning: £400-600
- Includes: Biocide pre-treatment, low-pressure cleaning, residual protection
- Duration: 1 day typically
- Results last: 3-5 years
Detached house (150-250m² render area):
- Professional cleaning: £600-900
- Includes: Full treatment, gutter clearing often included
- Duration: 1-2 days
- Results last: 3-5 years
Large detached/commercial (250m²+ render area):
- Professional cleaning: £900-1,500+
- Includes: Comprehensive treatment, access equipment if needed
- Duration: 2-3 days
- Results last: 3-5 years
What's Included in Professional Cleaning
- Full property assessment
- pH-balanced biocide application
- Appropriate dwell time (15-30 minutes)
- Low-pressure rinse (under 1000 PSI)
- Gutter clearing (often included)
- Residual protection treatment
- RAMS documentation if required
Long-Term Cleaning Costs
Over a 15-year period with cleaning every 5 years:
- Initial clean: £600
- Second clean (year 5): £600
- Third clean (year 10): £600
- Total 15-year cost: £1,800
The True Cost of Re-Rendering
Birmingham Area Re-Rendering Pricing
Typical semi-detached house (100-150m² render area):
- Basic cement render: £3,000-5,000
- Monocouche render: £4,000-6,000
- Silicone render: £5,000-7,000
- Duration: 1-2 weeks
- Lifespan: 20-30 years
Detached house (150-250m² render area):
- Basic cement render: £5,000-8,000
- Monocouche render: £6,000-9,000
- Silicone render: £7,000-11,000
- Duration: 2-3 weeks
- Lifespan: 20-30 years
Large detached/commercial (250m²+ render area):
- Basic cement render: £8,000-15,000+
- Monocouche render: £10,000-18,000+
- Silicone render: £12,000-20,000+
- Duration: 3-4 weeks
- Lifespan: 20-30 years
What's Included in Re-Rendering
- Removal of old render (if necessary)
- Surface preparation and repairs
- Base coat application
- Top coat application
- Finishing and detailing
- Scaffolding (major cost component)
- Waste removal
- Colour matching or selection
Hidden Re-Rendering Costs
Beyond the quoted price, consider:
- Scaffolding: £800-2,000+ (often 20-30% of total cost)
- Substrate repairs: £500-2,000+ if underlying issues discovered
- Window/door trim replacement: £200-800
- Decoration disruption: Internal redecoration if needed
- Temporary accommodation: Rarely needed but possible for extensive work
- Planning permission: May be required for listed buildings or conservation areas
Long-Term Re-Rendering Costs
Over a 30-year period:
- Initial re-render: £6,000
- Cleaning every 5 years (years 5, 10, 15, 20, 25): £600 × 5 = £3,000
- Total 30-year cost: £9,000
Cost Comparison: The Numbers
Scenario 1: Sound Render with Cosmetic Issues
Option A - Professional Cleaning:
- Immediate cost: £600
- 15-year cost (cleaning every 5 years): £1,800
- 30-year cost (cleaning every 5 years): £3,600
Option B - Re-Rendering:
- Immediate cost: £6,000
- 15-year cost: £6,000 (no re-render needed yet)
- 30-year cost: £9,000 (includes maintenance cleaning)
Savings with cleaning over 15 years: £4,200
Savings with cleaning over 30 years: £5,400
Scenario 2: Render Requiring Replacement in 10 Years
Option A - Clean Now, Replace Later:
- Year 0: Clean (£600)
- Year 5: Clean (£600)
- Year 10: Re-render (£6,000)
- Year 15: Clean (£600)
- 15-year cost: £7,800
Option B - Replace Immediately:
- Year 0: Re-render (£6,000)
- Year 5: Clean (£600)
- Year 10: Clean (£600)
- Year 15: Clean (£600)
- 15-year cost: £7,800
Result: Similar long-term cost, but Option A spreads expenditure and delays major capital outlay.
When Cleaning Is the Right Choice
Clear Indicators for Cleaning
- Render is structurally sound (no cracks, delamination, or blown areas)
- Primary issue is discolouration or biological growth
- Render is less than 15-20 years old
- No damp penetration issues
- Budget constraints favour lower immediate expenditure
- Property not being sold imminently (cleaning provides excellent ROI for ongoing ownership)
Benefits of Choosing Cleaning
- Cost-effective: 90% cheaper than re-rendering
- Quick: Completed in 1-2 days vs. 2-3 weeks
- Minimal disruption: No scaffolding, no major works
- Preserves original render: Maintains property character
- Immediate results: Dramatic transformation in one day
- Extends render life: Removes damaging biological growth
- Flexible timing: Can be done almost any time of year
Expected Results from Professional Cleaning
- Removal of 95%+ of biological growth and staining
- Restored original colour (or close to it)
- Results lasting 3-5 years with quality treatment
- Residual protection against regrowth
- Extended render lifespan by removing damaging organisms
When Replacement Is Necessary
Clear Indicators for Re-Rendering
- Significant cracking (wider than hairline)
- Delamination or blown render (sounds hollow when tapped)
- Severe erosion exposing substrate
- Damp penetration through render
- Render age exceeding 30-40 years with deterioration
- Previous repairs failing
- Desire to change render type or colour
Benefits of Choosing Re-Rendering
- Long-term solution: 20-30 year lifespan
- Structural improvement: Addresses underlying issues
- Modernization: Opportunity to upgrade to better render systems
- Colour change: Complete aesthetic refresh
- Property value: Significant improvement for sale purposes
- Warranty: Typically 10-25 years depending on system
Modern Render Options
Cement render (traditional):
- Lowest cost option
- Requires painting every 5-10 years
- Good durability
- Most common in Birmingham area
Monocouche render:
- Mid-range cost
- Coloured throughout (no painting needed)
- Self-cleaning properties
- 20-25 year lifespan
Silicone render:
- Premium cost
- Excellent water resistance
- Superior self-cleaning
- 25-30 year lifespan
- Highly breathable
The Middle Ground: Repair and Clean
For render with minor structural issues and cosmetic problems:
Combined Approach
- Repair cracks and damaged areas: £500-1,500
- Professional cleaning: £600
- Total cost: £1,100-2,100
This approach:
- Addresses structural concerns
- Restores appearance
- Costs 70-80% less than full re-rendering
- Extends render life by 5-10 years
- Allows time to budget for eventual replacement
Making Your Decision: A Framework
Step 1: Assess Your Render
Get a professional assessment (often free from cleaning companies):
- Tap render to check for hollow sounds (delamination)
- Inspect for cracks wider than hairline
- Check for damp patches inside
- Assess overall structural integrity
Step 2: Consider Your Timeline
- Selling within 1-2 years: Cleaning provides excellent ROI for sale
- Long-term ownership: Cleaning extends render life cost-effectively
- Render nearing end of life: Consider replacement timing
Step 3: Evaluate Your Budget
- Limited immediate budget: Cleaning is the clear choice
- Capital available: Consider if replacement is actually needed
- Spreading costs: Cleaning now, replace later if needed
Step 4: Factor in Disruption Tolerance
- Minimal disruption preferred: Cleaning (1-2 days)
- Can accommodate major works: Re-rendering (2-3 weeks)
The Washzilla Recommendation
At Washzilla, we're honest about what your render needs:
Our Assessment Process
- Free survey: We assess structural integrity, not just appearance
- Honest advice: If your render needs replacement, we'll tell you
- Clear options: We present cleaning, repair, or replacement recommendations
- No pressure: We want you to make the right decision for your property
When We Recommend Cleaning
- Structurally sound render with cosmetic issues
- Biological growth is the primary problem
- Cost-effective solution appropriate for your situation
- You want to extend render life before eventual replacement
When We Recommend Replacement
- Structural issues present
- Render beyond effective cleaning
- Long-term solution needed
- We'll refer you to trusted rendering specialists
Real Birmingham Case Studies
Case Study 1: Victorian Semi in Moseley
Issue: Heavy black streaking, green patches, render appeared to be failing
Assessment: Structurally sound, purely cosmetic biological growth
Solution: Professional cleaning
Cost: £550
Result: Render restored to near-original appearance, results lasting 4+ years
Savings vs. re-rendering: £5,450
Case Study 2: 1980s Detached in Solihull
Issue: Discolouration, minor cracking, some blown areas
Assessment: Repairs needed plus cleaning
Solution: Crack repairs (£800) + professional cleaning (£700)
Cost: £1,500
Result: Extended render life by 8-10 years
Savings vs. immediate re-rendering: £5,500
Case Study 3: Modern Build in Harborne
Issue: Severe cracking, delamination, damp penetration
Assessment: Render failure, replacement required
Recommendation: Full re-rendering
Outcome: Referred to specialist renderer, cleaning would have been wasted money
The Bottom Line
For the majority of Birmingham properties with discoloured or stained render, professional cleaning is the clear financial winner:
- 90% cost saving vs. re-rendering
- 3-5 year results from a single treatment
- Minimal disruption (1-2 days vs. 2-3 weeks)
- Extends render life by removing damaging biological growth
- Immediate transformation for a fraction of replacement cost
However, when render is structurally compromised, replacement is the only sensible option. The key is getting an honest, professional assessment to determine which category your property falls into.
Don't assume your render needs replacing just because it looks bad. In most cases, professional chemistry-led cleaning can restore it to near-original condition for less than 10% of replacement cost—and those savings can be invested elsewhere in your property or simply kept in your pocket.
Get a professional assessment today and make an informed decision based on facts, not assumptions. Your wallet will thank you.