Mundic block destroys property values overnight.
Found primarily in Cornwall and Devon, this mining waste material was used in thousands of homes. When testing reveals Class C mundic, your property becomes virtually unsellable through traditional routes.
Banks won’t touch it.
I’ve bought properties with mundic problems. From Class B uncertainties to confirmed Class C failures, I’ve navigated these sales before.
In this guide, I’ll explain the mundic classification system clearly. You’ll learn what each class means for your sale, which buyers will still consider your property, and realistic price expectations based on your test results.
Most importantly, you’ll discover whether retesting makes sense or just delays the inevitable.
- The Mundic Block Problem in Cornwall and Devon Properties
- Selling Options for Properties with Mundic Block
- How Mundic Block Affects Mortgageability and Property Values
- Disclosure Requirements and Testing Obligations
- Remediation Possibilities for Mundic Block Properties
- Managing Sales in Mundic-Affected Regions
- Why Property Buyers Today Purchases Mundic Block Properties
The Mundic Block Problem in Cornwall and Devon Properties
Mundic block is a special concrete made with local stone. Builders used it mainly in Cornwall and Devon from 1900 to 1950.
The blocks contain minerals from old mines. These minerals react badly over time. The concrete crumbles slowly from inside. Walls get weaker every year.
Three classes exist. Class A means safe and sound. Class B shows some problems but stays stable. Class C means serious damage and danger.
Warning signs:
- Cracks in walls
- Crumbling concrete
- Bulging walls
- Loose blocks
Surveyors test for mundic during inspections. They take samples and send them to labs. Results show which class your property is.
I’ve helped sellers with non-standard construction problems, including mundic. Class C buildings often can’t be saved.
Long-term risks are massive. Walls can collapse eventually. Entire buildings might need knocking down. Check the RICS mundic guidance if you’re in Cornwall or Devon.
Selling Options for Properties with Mundic Block
Here are the 3 primary approaches to sell your property when mundic block exists…
Estate Agents
The conventional route presents extreme challenges for houses with mundic block:
- Standard sale duration: 12-24 months (severely extended – mundic block is primarily a Cornwall issue affecting mortgageability)
- Most sales fall through when mundic tests reveal Class C or failing results
- You need agents experienced with mundic properties and Cornish construction
- You’ll encounter these costs:
- Agent commissions (up to 3%)
- Solicitor fees (up to £4,000)
- Mundic testing (£400-£800)
- Structural engineer reports (£600-£1,500)
- Complete rebuilding if Class C (£40,000-£150,000+)
- Extremely limited buyers (cash only for Class C)
Property Buyers Today
When mundic block makes your property difficult to market:
- We can complete within just 7 days
- No financing complications or mundic testing needed
- What you receive:
- No agent fees
- We handle legal costs
- No property viewings – we buy mundic properties as they stand
- No rebuilding expenses – we manage mundic issues ourselves
- We understand mundic and Cornwall-specific problems
- Completion date you can depend on
- Trade-off: Obtain up to 85% of property value (often significantly better than rebuilding costs)
Professional cash house buyers like Property Buyers Today understand mundic block complications and handle all procedures.
Property Auction
Auctioning attracts purchasers who deal with mundic properties:
- Duration: 3-4 months
- Sale finalises instantly when gavel drops
- Important factors:
- Property sold as-is – bidders review mundic test results
- Attracts local developers familiar with mundic issues
- Perfect for Cornwall investors – draws appropriate buyers
- Mundic classification disclosed in auction legal pack
- Wait 4-8 weeks until auction date
- Wait 28 days to finalise transaction
- Entry costs (up to £1,000)
- Auction house charges (up to 6%)
- Full mundic test information must be disclosed to all bidders
Review our guide on selling a house at auction to understand how this process works for properties with mundic block.
How Mundic Block Affects Mortgageability and Property Values
Mundic block construction makes your home nearly impossible to sell. The concrete contains minerals that crumble over time. Walls can collapse if the problem is severe.
Most mortgage lenders refuse to finance mundic properties without testing. Your home becomes un-mortgageable to the majority of buyers. Property values crash when mundic is discovered.
Banks Demand Professional Mundic Testing
Mortgage lenders won’t approve loans without a mundic test report.
The test costs £500-£1,500 depending on property size. Specialist surveyors examine your walls and concrete. They determine how dangerous the mundic content is.
No test means no mortgage for your buyer. Banks have strict policies about this. Even cash buyers usually want testing done first.
Class A Properties Might Get Mortgages
Mundic testing puts homes into Class A, B or C categories.
Class A means low mundic content and minimal risk. Some lenders will provide mortgages for these properties. Your home keeps a reasonable value with Class A rating.
Class B is a moderate risk with some lender restrictions. Banks want extra surveys and conditions. Getting mortgages becomes much harder.
Class C Properties Are Basically Unsellable
Class C rating means high mundic content and serious structural risk.
No mainstream mortgage lender will touch these properties. Your buyer needs cash to purchase. That’s less than 5% of potential buyers.
Even cash buyers offer tiny amounts for Class C homes. They know the walls might need replacing completely. Rebuilding costs reach £100,000 or more.
Your Property Loses 50-100% of Its Value
Untested mundic properties sell for almost nothing.
Buyers assume the worst without a test report. If your home would normally fetch £200,000, you might get £20,000 to £100,000. Class C properties often sell for land value only.
Class A properties lose 10-20% of their normal value. Class B homes drop 30-50%. Cornwall Council guidance on mundic testing explains the severity of this issue.
Only Cornwall and Devon Buyers Understand
Mundic mainly affects properties in Cornwall and parts of Devon.
Local buyers know about the problem immediately. They’ve seen mundic disasters before. Outside buyers run away when they hear the word.
Your buyer pool shrinks to local cash investors only. They specialise in mundic problems. All of them demand huge discounts.
Insurance Companies Won’t Cover Mundic
Getting building insurance is nearly impossible with mundic.
Most insurers refuse to quote for untested properties. They won’t risk covering crumbling walls. Even Class A properties face higher premiums.
Class B and C properties can’t get insurance at all. Buyers can’t complete purchases without cover. Your sale collapses before it starts.
Repair Costs Destroy Any Sale Hopes
Fixing mundic problems costs tens of thousands of pounds.
Class B properties might need wall reinforcement work. That costs £20,000-£50,000. Class C properties need complete rebuilding.
Nobody wants to buy a home needing £100,000 of structural repairs. The numbers don’t make sense. Buyers choose properties without these massive costs instead.
Disclosure Requirements and Testing Obligations
You must tell buyers about mundic in Cornwall and Devon. The TA6 form asks directly about it.
RICS runs the official testing scheme. Professional surveyors take samples from your walls. Labs test the mineral content carefully. Reports classify your property as A, B, or C.
Testing shows:
- Mineral types present
- Damage level found
- Safety classification
- Remediation needs
Testing costs £500 to £1,500, depending on property size. You need this before selling in affected areas.
Previous test reports help if recent. Results over five years old need updating, though. I’ve watched sales collapse when sellers provided old reports.
Hiding mundic breaks the law. Buyers sue easily after completion. Courts award big damages for non-disclosure. Your solicitor handles all testing paperwork.
Insurance gets tricky, too. Class B might get indemnity cover. Class C buildings can’t get insurance at all.
Check the official RICS scheme before listing your home.
Remediation Possibilities for Mundic Block Properties
Fixing mundic costs huge money. Complete rebuilding runs £80,000 to £200,000 easily.
Some walls can be replaced partially. Engineers remove bad blocks and rebuild sections. This costs £30,000 to £70,000 typically. Underpinning adds strength underneath. Budget another £20,000 to £40,000 for this.
Repair options:
- Complete rebuild
- Partial wall replacement
- Structural underpinning
- Steel reinforcement
Building approval is required for all work. Councils inspect carefully throughout. Work takes six to twelve months minimum.
The maths usually fails badly. I’ve seen properties worth £150,000 need £180,000 in repairs. Remediation costs more than the finished value.
Class C properties rarely justify fixing. The numbers never work out. Selling to specialists who buy structural problem properties makes more sense.
Successful repairs can improve classification. Class B might reach Class A after work. You need new testing and certificates proving this.
Check building approval rules before starting. Most owners sell as-is instead.
Managing Sales in Mundic-Affected Regions
Selling in Cornwall and Devon needs special knowledge. Everyone knows about mundic here. Buyers expect testing before they even view.
Local buyers understand the problem well. They ask about classification immediately. Class A properties sell normally. Class B means big price cuts. Class C buildings sell to cash buyers only.
Surveyors always test for mundic in these areas. Testing happens early in sales. Results take two to three weeks, usually. I’ve watched buyers wait nervously for lab reports.
Regional challenges:
- Mandatory testing delays
- Lender refusals common
- Big price reductions
- Many sales fall through
Banks won’t lend on Class C properties ever. Class B gets mortgages sometimes with conditions. Expect lenders to request extra surveys and engineers’ reports.
Negotiations get tough fast. Class B buyers want 20% to 30% off. Class C offers come in 50% to 70% below the normal value.
Sales take longer here. Testing, reports, and surveys add months. Contract exchange delays happen constantly with mundic.
Fall-through rates hit 40% to 50% in mundic areas. Many buyers panic after testing results arrive.
Use local solicitors who know mundic well. They handle testing and reports smoothly. Consider quick sale companies for Class C properties.
Why Property Buyers Today Purchases Mundic Block Properties
I’ll be real with you…
Mundic block construction makes properties virtually unsellable in traditional ways. The concrete blocks can deteriorate, most lenders refuse to provide mortgages, and buyers in affected areas know exactly what it means. If you’d rather escape this situation now, I totally get it.
Let’s be honest—our offer won’t be the full market value because we factor in our costs and need to move properties on quickly.
Still, here’s why homeowners with mundic block issues still decide to sell their house fast through us…
Speed
Most house sales take months, but we can buy your property in as little as 7 days.
This quick process is perfect if you need to move soon or want to avoid being stuck in a long chain of buyers and sellers. We have the cash on hand so don’t need to wait for mortgages or a chain to collapse.
Guaranteed Sale
Did you know 1 in 3 sales fall through on the open market?
We know how frustrating it is to get 6 months into a process and have a buyer pull out.
When we give you the final price for your house, that’s the amount you’ll get. Guaranteed!
No Costs
You won’t face any costs with us.
We handle all the expenses involved in buying your property, including legal fees and surveys. You get cash in your bank when the sale is complete, and there are no surprise estate agent commissions to worry about.
No Stress Or Hassle
Our team supports you through the whole selling process.
We keep you updated about what’s happening and answer any questions quickly. You’ll always understand what’s going on with your sale and what happens next.
Free Property Valuation
Our property experts will value your house at no cost to you.
They look carefully at your property and check local market prices to give you an accurate figure. This professional service comes with no obligations.
No Viewings Required
Forget about cleaning and tidying for viewings.
We don’t need multiple visits or open houses to make our offer. This means no strangers walking through your home, and no disruption to your daily life.
All Properties Welcome
Whether your house needs work or is in perfect condition, we’ll buy it.
We have experience with all types of properties and conditions. This means you can sell your house to us no matter what state it’s in.
Professional Legal Service
Our expert team manages all the legal requirements for you.
We work with experienced property lawyers who make sure everything runs smoothly, and put your property at the top of their list. This gives you peace of mind that your sale is being handled properly from start to finish.
