Building Defects a shortfall in performance

A short Article by Noel Larkin MSCSI MRICS

As Building Surveyors, the identification of building defects forms a primary part of our daily work. More importantly, I see the remedying of building defects and the specification of practical, cost effective, solutions is our key role.

The identification of some defects can be easy however the identification of an appropriate repair process can sometimes be more complex. For example, the identification of pyrite can be relatively straightforward but the process to be followed to remedy the defect may not be. Questions arise like, how to support perimeter walls when sub-floor fill is removed, how to deal with new radon barrier and existing damp proof courses connections etc.

Our profession is evolving. The legacy of the building boom and an uncontrolled building industry, has now come home to roost with the emergence of pyrite damage, buildings that fail to comply with Building Regulations, failure of roofing materials, failure of cladding systems, failure of glazing, improper fire stopping etc. These are the areas that as Chartered Building Surveyors we are now dealing with.

The evolution of ‘Vendor’s Surveys’ has put Building Surveying members at the coal face in identifying these issues on behalf of vendors and purchasers alike. The evaluation of defects and advice with regard to repair costs now forms a major part of Chartered Building Surveyor’s work.

As Building Surveyors we are specifically trained for this work. Our knowledge of Building Regulations, materials, life cycles, methods of construction and detailing, leaves us best placed to advise on the built environment in all its forms. This gives us a particular expertise and an advantage in advising on the built environment and the type of issues which can come to light post construction.

Our clear understanding of how the key components of a building are assembled, gives us a particular advantage when surveying a property, particularly in terms of an appreciation of where items such as fire stopping should be present and where one can easily check to establish if the correct processes have been followed during the construction phase. It is important that all Building Surveying members continue to promote our profession as the “go to” experts when dealing with the built environment.

Defects / Building Failures

BRE Digest 268 describes building defects as ‘a shortfall in performance.’ A defect can lead to eventual failure if not corrected.

The occurrence of building defects is not a new phenomenon. Building has always been based around a trial-and-error process with change and adaptation taking place over many centuries. Without this human aspiration to improve or be innovative, building processes and building forms would have remained static. Therefore, defects are a typical by-product of this continuing learning process or innovation. If nothing changed and we were content with tried and tested methods of construction we would still be living in cold damp mud huts. High profile building failures, such as the May 1968 Ronan Point gas explosion in London, exposed design flaws leading to disproportionate progressive collapse of the building, and in turn changed the way engineers design tall buildings. This is testament to an evolving industry within the very recent past. However, the argument that “getting it wrong is part of getting right” will fall on deaf ears, if trying to explain to a client that this is why his new building leaks.

There are of course many variables involved in the building process, each with a contributing factor to the finished product, and each can have its own effect on the potential for defects to arise. These are weather, availability of skilled labour, familiarity with products or processes, time, cost, building control / supervision, cheap alternatives. Unless these variables are correctly intertwined, there is potential for defects to arise.

When NASA engineers designed the space shuttle their superiors informed them that they wanted it delivered on programme, within budget and of good quality. The engineers quickly responded to their bosses that they could pick any two of these aspirations. The same limitations apply to building.

As Building Surveyors, we need to continually review our understanding of the built environment, compatibility of materials, how buildings work in practice etc. This is a massive area to have and overall understanding of. Innovations in design and materials continue and it is our responsibility to remain on top of this through continued professional development or lifelong learning.

The size of this task becomes apparent if one considers the art of brewing. I recently saw a bill board advertising larger. The larger was, it claimed, the result of three hundred years of brewing expertise. Three centuries for one product that continually evolved yet remained the same. When you compare this to the array of products available in the construction industry and the evolution of each of these you begin to understand the enormity of our task.

Causes of Defects

So we know that variables in the construction process can lead to defects, but in general terms there are three main causes of defects. There are many sources but the three main causes are as follows, dampness, movement and chemical or biological change

Dampness can occur from many sources, such as rainwater, surface water, services, construction water and condensation.

Movement can be brought about by changes in temperature, moisture, applied loading, dead loading, accidents, ground movements, vibration chemical changes in materials

Chemical or Biological Change can be brought about by dampness, corrosion, changes in temperature, electromagnetic radiation, fungal attack, insect attack.

It can be seen from the above that although there can be multiple sources of defects, the clear thread which runs through the above list is moisture. As Chartered Building Surveyors we understand that moisture is at the heart of many problems with buildings.

The fact that there can be multiple sources and issues with compatibility of materials etc. means that each defect must be considered fully and where necessary further more detailed investigation should be undertaken before a diagnosis is made. Any investigation of a defect must be thorough and each possible cause of a defect must be considered fully before one jumps to a conclusion or diagnosis.

In conclusion, all buildings will have defects to one degree or another.

We cannot have buildings that are maintenance free. We cannot have innovation without the risk of failure. We cannot expect large scale development without the emergence of defects in either materials or workmanship. This is normal and the way it has always been.

The continual emergence of defects in the built environment is an opportunity for Chartered Building Surveyors as leaders in the assessment of the built environment and as experts in Building Pathology.

The correct diagnosis of defects and the repair process to be followed in each individual case, dependant on “performance expectations” of the building user, is where Building Surveyors can add real value to their clients. This advice can range from do nothing, to complete renewal or replacement.
Our work for many years to come will be involved in the correction of defects brought about by the recent building boom and the lack of effective building control during that period.

However if we rely on history as a guide to what might happen in the future, Chartered Building Surveyors will be dealing with defects arising in new buildings for generations to come.

Chartered Building Surveyor