There is no denying that older, historic buildings have a unique charm. On the surface, looking to buy an older building or property has a range of advantages: they’re usually in prime locations, they have distinct architectural features and, in the long-term, can result in being a smart structural investment. Older buildings do come with challenges however, and the condition of the structure is something to consider whether you have already invested or are looking to.
Regents Street Disease
The main factor that impacts a historic structure’s safety and condition is corrosion of the steelframe. Relating to early 20th Century buildings, this is commonly referred to as Regents Street Disease, effecting buildings with stone or terracotta cladding over a steelframe. Pre-1950, typical construction of city centre buildings involved no gap between the steelframe and cladding materials. These façade materials are often porous, so over time and out of sight, water ingress causes the steel frames to corrode. This rust expands the steel and results in movement that generates cracks in the stonework and, in some cases, can lead to masonry falling from the façade. This posed a huge danger in busy cities, so changes in construction techniques were made post 1950s, requiring a cavity between the frame and masonry, allowing for some movement of the frame without dislodging the external façade.
There are thousands of buildings that still exist which have been constructed this way, and therefore need a condition survey which can accurately identify any hidden structural defects in order to prevent any harm caused to future occupants or visitors
What is a Condition Survey?
A condition survey is a visual inspection carried out by qualified chartered building surveyors to provide objective information about the physical, mechanical and electrical condition of your building. If you have recently made an investment in an older building, this is one of the very first things you should arrange, in order to see how much renovations will cost.
At Structural Healthcare, we specialise in corrosion condition surveys that lead to designs of corrosion mitigation systems which are to specifically enhance the functionality, safety and resilience of your historic investment. We have a range of condition surveys which can highlight any prominent issues, such as:
- Concrete cover and delamination surveys
- Half-cell potential surveys (surface contour and 3-D intrusive)
- Chemical testing using UKAS laboratories
Our condition surveys are designed for both masonry and concrete structures – for example, you may have invested in a reinforced concrete parking structure, as opposed to a historic building. Both types of structures are heavily impacted by corrosion and need the same in-depth corrosion surveys to ensure mitigation of any problems.
|Half-cell potential corrosion wheel survey to a portion of Level -2 showing variability of corrosion risk of a reinforced concrete parking structure.|
So, now that your condition survey has been carried out and you are fully aware of any structural problems, what’s next? If you want a positive return over time, you need to consider a structural resilience strategy which will ensure the whole life performance of the building, minimizing future maintenance costs at the same time.
Ensuring Whole Life Performance of your Investment
Structural Healthcare recommends to follow-up the results from the condition survey, a bespoke corrosion mitigation system to be designed which can be installed within your structure. These systems use a range of cathodic protection methods, which has shown to be ‘the only rehabilitation technique that has proven to stop corrosion…’ alongside embedded corrosion sensors to continuously give asset owners true insight into the condition of their investment.
Structural Healthcare provide effective after care or In Use services for these installed systems, as they are managed on an open network system: the Achilles Interactive Management Server (AiMS). Service life tracking reports are distributed on a monthly, quarterly and annual basis, and owners can log into a dashboard at any time to view or pull valuable data.
Not only is this a cost-effective solution for the asset owners, but it also protects the value of the asset. It is a fact that buildings suffer from deterioration, and as they age, they become less valuable than new buildings as a result of wear and tear and changes in technology. Corrosion mitigation systems, however, is an opportunity for asset owners to take advantage of smart technology and retrofit it into an ageing asset, protecting it and giving it a new lease of life.
The use of structural health monitoring via AiMS also provides a permanent record of performance of the structure, which would be vital for due diligence if you look to sell your investment in the future.
From an environmental aspect, implementing a corrosion management strategy for your investment is also sustainable, as you are recycling an ageing structure. Demolition is no longer an option for these buildings unless they are beyond repair – RIBA has stated that every year 50,000 buildings are demolished in the UK, producing 126 million tonnes of waste, which represent two-thirds of the UK’s total waste. An installed corrosion mitigation system prevents extensive construction work on structures, therefore lowering harmful emissions.
Investment in an old structure presents many profitable opportunities, but ultimately the condition of the structure is top priority to maximise this. Harnessing new technology through carrying out in-depth condition surveys and following up with the installation of a corrosion mitigation system provides a whole life controlled solution for your old structure. Being connected through the Internet of Things and having clear insights from structural health monitoring results in lower costs, a safer building and, in the long-term, your investment is protected.
To learn more about Structural Healthcare’s condition surveys and whole life system designs, contact us at 01744 613832 or firstname.lastname@example.org
 Scheffey, C. F. (1981), Bridge Deck Deterioration- A 1981 Perspective, FHWA Memorandum, Federal Highway Administration Office of Research