Mundic block mortgages are very hard to get due to the issues with the property.
Most mortgage lenders are worried that a mundic block mortgage could end up in default if the property falls into a state that is unrepairable due to the mundic blocks.
What are Mundic blocks?
Mundic blocks are usually found in Cornwall and Devon.
In lay terms a Mundic block is a kind of block which deteriorates faster due to a particular kind of waste generated from the mines.
In more complex terms: “The Cornish word mundic is now used to describe a cause of deterioration in concrete due to the decomposition of mineral constituents within the aggregate. A typical source of such aggregates is metalliferous mine waste.”
Mundic blocks came about between 1900 and 1950. Rather than let the mine waste go to waste the Cornish people decided to use them as part of their concrete mixture when building houses. A lot of Cornish houses are therefore built with these Mundic blocks which deteriorate over time and much faster.
There are three ingredients required to create concrete: aggregate, cement, and water. The aggregate is formed of pieces of rock that require sticking together. This is where the mine waste was added.
The official term for Mundic blocks is sulphide mineral pyrite.
What are the issues with Mundic block mortgages?
Because it is hard to tell how much mundic block a property may have in it and how fast it is likely to deteriorate, a lot of mortgage lenders will not offer mundic block mortgages and you will need a specialist mortgage broker to find a mortgage lender willing to offer you a mundic block mortgage.
When evaluating your home after a mortgage offer the mortgage lender will instruct a property survey and insist n a mundic block test if your home is located within Devon and Cornwall and certainly if your home was built or modified with 1900 and 1960 in that region.
How can you get a mundic block mortgage?
You can usually get a mundic block mortgage if your property survey returns some good news from the mundic block test.
Once the property survey is completed, the report on the Mundic blocks will be provided.
An A1 or A2 grade is great news as this means that the concrete doesn’t contain any potentially harmful materials or contains so few that they are unlikely to be problematic in the future.
If a sample of Brick from the home you want to purchase contains more than these levels of mundic, it may be classed as a grade A3 which isn’t great news but isn't also the worse news.
An Ac means your property sits just in between the good and bad line and some mortgage lenders may accept this grading and some may not. Your mortgage broker will be able to assist you in showing your mortgage lenders who accept this grading and offer you a mundic block mortgage.
The issue with an AC grading is that it is classified as special testing and the test is expensive, time-consuming, not appropriate for every case.
If your property gets a grade B or C for its mundic test then you will definitely not get a mortgage as this indicates that Mundic makes up more than 30% of the concrete in your property and the damage may already be visible.
If it can be proven that the mundic is limited to a specific part of the property, you may be able to replace it with a modern material in order to obtain a mortgage on the property.