Project Description

Rusting and delaminated steel work – Residential and commercial property repairs, Christchurch

This building was an existing mixed-use 1960’s steel frame commercial and residential structure, that had a cantilevered terrace for the first-floor residential units – providing a space for the residents to enjoy the views.

After we made an initial visit, it was clear to us at SWJ Consulting that the terrace was not designed to hold the weight of the residents, but that it was originally intended as a canopy for the commercial units below. However, the residents were using it regularly and the landlord had even fitted doors to access it.

The external steelwork of the terrace had not been protected and it was rusting and delaminating. The drainage had failed because of its age and due to not being maintained properly, and rainwater was sitting in the flanges of the beams. Where the cantilevered terrace had been used by the residents, putting more weight on it, the structure had deflected at the outside edge to a point where there was no fall on the drainage pipes, causing water to sit in the pipework and leak onto the steel. Normally this wouldn’t cause to much of an issue, but given the proximity to the sea, a higher concentration of windblown salt spray should have been expected and the steelwork protection inspected more regularly.


Project Team

Client: Private Client

Contractor: SER Ltd

We designed a scheme to remove the delaminated and rusted steelwork, splice on new protected steel, and reinstate the canopy making allowance for its use as a terrace balcony.

According to Premier Guarantees, additional guidance of developments in costal environments, ( steelwork should have a minimum galvanising coating of 710g/m2 when within ½ a km of the shoreline.

If we are working on a project from the early design stages, we can look to identify the likely corrosion issues and design a solution that will limit them. This includes considering the shape and geometrics of the building, using a selected backfill around a buried structure, using corrosion inhibitors and protective coatings and ensuring there is adequate drainage.

As with the project in Dorchester, we are often called in for remedial works and can work with the existing structure to sure-up existing buildings and add new protected steel works where necessary.

If you have a property or project on the south coast and are concerned about the corrosion of your steel work, and how to prevent it, then please do give us a call on 02381 920656 or email