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CROSS Safety Report

Galvanic (bimetallic) corrosion not considered in cladding design

Report ID: 811 Published: 30 June 2022 Region: CROSS-UK


A cladding designer and installer did not consider galvanic (bimetallic) corrosion which led to remedial works being required. 

Key Learning Outcomes

For cladding designers and installers:

  • Selecting the correct fixings and isolating materials where dissimilar metals are jointed together is important to ensure they perform as expected
  • Cladding design and installation should be given the same degree of attention as the primary structure during both design and construction to improve safety, reliability and longevity
  • The anticipated life span of the fixings should be noted in the operation and maintenance manual
  • Manufacturers' instructions provide helpful guidance on fixings. The Construction Fixings Association (CFA) website and CIRIA publication C778 Management of safety-critical fixings are also useful references

Full Report

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This section contains the Full Report submitted to CROSS and describes the reporter’s concerns or experiences. However, the text has been edited for clarity, and identifiable details have been removed to ensure anonymity and confidentiality. If you would like to know more about our secure reporting process, or submit a report yourself, please visit the reporting to CROSS-UK page.


On a recent project, says a reporter, the cladding designer and installer did not consider galvanic (bimetallic) corrosion. To prevent this from happening stainless steel bolts were retrofitted with plastic sleeves where they were in contact with aluminium cladding framework. Plastic spacers were used where different metals were being joined together. The reporter found that the installers had a lack of understanding of the problem. All connections are now hidden behind finishing panels and not readily available for inspection.

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