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We are Cornwall’s leading experts in Mundic Testing. Properly known as a Concrete Screening Assessment, Stimson and Tieken Chartered Surveyors  have advised both The Council of Mortgage Lenders and the Royal Institution of Chartered Surveyors on Mundic testing procedures and are acknowledged in all RICS  mundic testing guidance notes. We are approved by all lenders.

The term Mundic has become used as the generic name in Cornwall, and parts of Devon, for concrete which is made with aggregates containing deleterious mining aggregates .

A mundic Test or Concrete Screening Assessment should only be undertaken by a suitably qualified Chartered Surveyor carrying the RICS logo (Royal Institution of Chartered Surveyors). Your mundic test may be rejected by your mortgage lender.

A Stage I mundic test is a  procedure which involves the removal of 50mm concrete core samples from various elements of the property in accordance with the RICS 3rd edition Mundic Guidance notes of 2016. An experienced chartered surveyor ( carrying the RICS logo) will undertake a  site inspection and instruct an experienced drilling operative where to remove concrete core samples from. The sample locations will be annotated with detailed notes and the samples bagged and tagged for submission to a petrographic laboratory.

The laboratory, who are independent , will supply the supervising surveyor with a stage 1 petrographic report indicating the aggregate types used in the  submitted samples. If deleterious aggregates (such as mining )are found , Stage II tested will be recommended. 85% of properties pass a stage I assessment and are given a Classification A1.

If deleterious aggregates are found the Stage II assessment recommended will depend upon the location and condition of the concrete type submitted. You can still get a mortgage if the property passes a stage II test. The Classification will be A2. 60% of properties pass stage II and are suitable for secured lending.


In certain circumstances , should the property fail stage II, a stage III assessment might be recommended. This is not for the faint hearted as it takes a year and can cost in excess of £5,000.00 plus VAT. A number of properties with Mundic have passed Stage III but these are in known locations. Discussion with our surveyors is recommended.

All sample locations are made good with cement but are not decorated.

During the early part of this century, builders and concrete manufacturers made extensive use of the readily available mine spoil tips in the production of concrete. These tips were widespread throughout the county wherever mining activity had taken place. The tips were made of crushed, broken stone, diminishing to dust, all being of ideal size for use as an aggregate and binder in concrete.

The unsatisfactory nature of these aggregates was not fully recognised until after the Second World War when British Standards and improved quality control gradually eliminated their use. Therefore it is generally considered that any property of concrete construction built prior to 1950 can be at risk, or may already show signs of deterioration.

There are occasional exceptions and therefore the local knowledge of an experienced Chartered Surveyor, specialising in this sphere, is invaluable.

Almost anyone owning or wishing to purchase a property built during the at risk period will, at some point, have need of a test.

In an advanced state of deterioration Mundic concrete becomes physically unsound and in many severe cases has lead to a need to demolish affected buildings.

In most instances Mundic materials cannot be identified visually insitu and the building may show no signs of distress whatsoever. For this reason a full concrete screening test is the only way of identifying that a property is unaffected.

Because of this anyone considering purchasing a property must have a test carried out in order to protect their investment. A cash purchaser should be mindful of the need for a satisfactory Classification for potential resale purposes. Any purchaser, or existing owner of a property considering a mortgage or remortgage, will be required by their bank or building society to have a test carried out prior to an offer of advance being made.

In most cases, anyone selling a property prior to the relevant date will find that a test carried out in advance is a useful marketing tool and can certainly save time at the contract stage.


RICS: The mundic problem

The Guardian: Crumbling concrete erodes house values in Cornwall and Devon

Only approved RICS surveyors carrying the RICS logo should undertake a mundic test warns the CML and RICS (3rd edition Mundic Guidance notes 2016)