One of the most common disputes investigated by CERAM subsidiary, CSMA involves coating problems on buildings. The stakes here are high as the cost of recovering buildings can run to several £million. Surface and interface analysis techniques are crucial to probe into the paint and determine the history as it was laid down. CSMA has several expert witnesses, one of which specialises in this kind of investigation.

A brand new office block in Kent (Head office for a leisure/insurance company) was experiencing severe paint delamination after less than one year in service. Remedial work was required to the tune of £18m.

The objective of this exercise was to determine a failure mode for the paint coating. The work was commissioned by the paint manufacturer who was being sued by the contractors.

Methodology & Results

SEM (Scanning Electron Microscopy) was used which provides high resolution images and basic chemical information. Cross sections of the paint structure were analysed, providing details on layer thicknesses and the sequence of paint application (the specified application was for 9 distinct layers!).

A study of previous work was also made along with a site visit and substantial literature searching. Statements from the paint suppliers and contractors were studied.

Conclusion

The paint itself was almost certainly not to blame. Rather, it was the manner the paint was applied which was the likely cause of the failure (incorrect preparation, incorrect application, adverse weather conditions). It would appear that the contractors had some concern over the quality of the pre-primed steel and added a “cautionary” primer layer which was incompatible and almost certainly exacerbated the situation.