Building surveys – survey now, save later
How early diagnosis protects the health of the built environment – the critical role played by building surveys
Regular building surveys are an essential part of a complete external building maintenance programme. As in-house maintenance personnel are often unable to access multiple areas of many buildings, such as roof coverings and upper floor masonry and ornamentation, our building restoration specialists at Thomann-Hanry® recommend professional building surveys and condition surveys every other year.
Inspections range from simple visual safety checks to the more in-depth tap tests and condition surveys required to plan a programme of future maintenance and remedial works.
With almost 20 years’ experience in the business to draw upon, Thomann-Hanry® Managing Director Mark Styles is well-versed in building inspections and surveys and the essential role they play in scheduling maintenance work and mitigating repair costs,
“By undertaking a comprehensive structural and condition survey, you can avoid the unforeseen costs of ongoing masonry repairs. Surveys check masonry for signs of damage, especially dangerous structural defects that could harm occupants of the buildings and passers-by – you don’t want to see anything falling off your building! We often find fractures in window heads and dentils, as well as slipped slates on mansard roofs – all potentially lethal accidents waiting to happen.”
A survey is paramount before starting any work on your façade – this will assess the extent and cause of any damage. A condition survey will guide the restoration teams in carrying out more invasive investigations to determine the most appropriate methods for repairs, alterations or other bespoke modifications. The more involved option of a comprehensive structural survey will not only help ensure your building is safe, but also identify areas requiring maintenance and expenditure in the future. This will allow you to plan and prepare your budgets accordingly – and prevent minor issues from turning into much bigger problems.
Regent Street Disease
For example, a small leak into a building can cause corrosion or wet rot. Another classic problem is ‘Regent Street Disease’ (RSD), where moisture permeates the outer envelope and attacks a building’s metal framework. As it corrodes, the metal frame expands, causing other materials to crack and ultimately fall away. The build-up of grime and pollution on a façade can often mask the early signs of RSD, so if a clean is undertaken prior to a proper inspection, the results can often flag up issues that would otherwise remain hidden.
Below are examples of RSD found by our building survey experts:
Having worked on countless buildings throughout London and further afield across the UK, Mark and his team at Thomann-Hanry® have seen it, done it and got the PPE, “As we often work on historic and listed buildings, the wonderful ornamental features championed by architects of years gone by frequently present problems.
For example, missing pointing around balusters is a big issue that can lead to further issues with corroding steel. Rusting balcony feet is another common problem which, unaddressed, can cause stonework to ‘pop’.
Building surveys at the right time in the year
So, when is the best time to carry out building surveys? Ideally, the optimal scenario is to inspect a building immediately after it has been cleaned. With accumulated layers of grime removed, cracking, corrosion and other potential issues can be identified sooner. As with all things, early diagnosis can head off problems before they escalate which, in the case of built structures, can save considerable unnecessary expense.
With scaffold or a MEWP (Mobile Elevated Work Platform) already in situ for cleaning, it also makes sense to take advantage of the increased access this offers. In more general, calendar terms, pre-winter surveys are highly recommended as they present an opportunity to address any cracking issues before the freeze-thaw process infiltrates the structure, opening cracks up.
With all its cost and timescale drawbacks, unless it’s already in place for cleaning or other remedial works, scaffolding generally isn’t an economically viable option for building inspections. Other conventional surveying techniques, such as abseiling, also entail issues with accuracy, since proximity to the building is subject to the prevailing weather conditions. Drones are increasingly being used for visual inspections, but clearly do not offer the advantage of being able to get close to the building and touch its surfaces, possibly leaving issues undetected and potentially creating a false sense of security.
The perks of the MEWPs
With a 37 metre (12 storey) range, MEWPs provide an agile alternative, perfectly suited to most buildings. In narrow London streets, where buildings are often clustered uncomfortably close together, these truck-mounted hydraulic systems are often the only way to reach otherwise completely inaccessible areas. As MEWPs are their primary work platform, Thomann-Hanry® are perfectly equipped to carry out detailed surveys, avoiding the inconvenience, cost and delays associated with building scaffold towers.
This access advantage is a significant factor in the uplift in survey-only projects undertaken by Thomann-Hanry® in recent years. Since the start of 2020 alone, the company have carried out standalone surveys at Alitalia House and Spirella House on Oxford Circus, Venture House in Soho and Café Royal in Piccadilly, amongst others.
Scaffold, abseiling, drone or MEWP… whichever method of access is chosen, those tasked with surveying the building also need to be trustworthy, independent operators with all appropriate licensing and accreditation.
With regard to reporting, the use of photography identifies the work that needs to be undertaken.
A more technological approach can be adopted, using lasers to scan façades to produce precisely accurate elevation drawings prior to the survey and allowing precise identification of locations requiring work. 3D models of existing conditions provide a precise context to support design, construction and operational decisions at every stage of any given project’s lifecycle.
As Mark Styles notes, the choice between photography and 3D imaging is very much client-driven: “Some property managers are comfortable interpreting computer modelled representations, whereas others prefer to see ‘real-world’ images of actual structural issues.”