Listed Buildings – Why should we protect our past?

We have a wonderfully diverse range of buildings in the UK and an equally diverse built environment which has responded to many years of change, development and progress. We clearly need to embrace change however our unique heritage in the UK would be quickly lost if all of our important and historic buildings were to be demolished and replaced with new modern buildings

Source: http://www.geograph.org.uk/

In 1709 Jonathon Swift, an Irish Cleric, Writer, Poet and Politician once commented; ‘nothing in the World is constant, but change’. In this fast moving World this is particularly true of the built environment which continues to find ways of re-inventing itself to keep pace with technology, innovation, population growth and to respond to issues such as depleting resources such as fossil fuels as well as global warming. 

We have a wonderfully diverse range of buildings in the UK and an equally diverse built environment which has responded to many years of change, development and progress. We clearly need to embrace change however our unique heritage in the UK would be quickly lost if all of our important and historic buildings were to be demolished and replaced with new modern buildings.  It is for this reason that selected buildings in the UK are given statutory protection, which makes it a criminal offence to alter, develop or demolish, depending on the protected status of the building (discussed below), without permission.  You will often hear protected buildings referred to as ‘listed buildings’. 

Listed buildings were first introduced during World War II as a means of deciding which buildings should be rebuilt if they were damaged by bombing. Not long after World War II had ended the introduction of the Town and Country Planning Act 1947 resulted in the compilation of the first list of buildings of special historical or architectural importance. Since then more and more buildings, monuments, site, landscapes and other miscellaneous items have been added to the list in order to preserve our heritage. Currently, listed buildings are designated by the Secretary of State for Culture, Communications and Creative Industries, acting on advice provided by English Heritage.  English Heritage will assess a building’s suitability for protected status and will then make a recommendation to the Secretary of State for Culture, Communications and Creative Industries, who can then decide to either accept or reject the recommendation.

If a building is designated for statutory protection (Listing), then it will be allocated into one of the following categories:

Categories of listed buildings (Source: English Heritage)

-   Grade I buildings are of exceptional interest, sometimes considered to be internationally important; only 2.5% of listed buildings are Grade I

-   Grade II* buildings are particularly important buildings of more than special interest; 5.5% of listed buildings are Grade II*

-   Grade II buildings are nationally important and of special interest; 92% of all listed buildings are in this class and it is the most likely grade of listing for a home owner.

The selection process for protected status is much wider than you would imagine.  When I ask my students ‘what is a listed building?’, the usual first reaction is an ‘old historic building’ where they usually provide examples such as Tudor timber framed buildings with thatched roofs or medieval castles.  Whereas, these examples given are not bad ones, the scope and selection of listed buildings is much wider than age and appearance.  The older a building is and its rarity will be a strong influencing factor in respect of whether it will receive protected status in addition to its appearance, both in terms of its architectural merit and whether the building is part of a collection of similar buildings.  Architectural merit will not always relate to ‘older’ buildings as there are examples of many more ‘modern’ buildings that have been listed as a result of their unique structure and form.  

Source: http://www.newrailwaymodellers.co.uk/

A good example is the signal box at Birmingham New Street Station (see image).  Many people are surprised to when they find out that the signal box is listed and therefore protected, as it does not follow the conventional perception of what people think a listed building should be.  An article in the Birmingham Post on-line (Link) describes the unique features of the signal box; ‘Designed by Bicknell & Hamilton and W.R. Healey and completed in 1965, the unapologetically bunker-like structure is an honest expression of its utilitarian function. Standing five storeys high above track level, the building gives no clue of the hive of activity that exists within its four walls. The technology inside is of the same era as the exterior façade and was revolutionary for its time. The Relay Room sits just above street level and houses enormous banks of algorithmic electronic relays, known as Wespacs, which are programmed to calculate legal routes for the trains to take.’

A building may be also listed because it represents a particular historical type.  A good example of this is the prefabricated houses that were erected in the 1940’s as a means of providing housing quickly for those affected by bombing during the war.  I have previously written an article on 1940’s prefabs which you may find of interest (Link).  These houses were only designed to solve a short term problem, however as the majority have now been demolished the ones that remain provide a permanent insight (because they are now listed) into a unique form of simplistic construction, one that I have to admit I find fascinating.  If we did not have the ability to protect these types of buildings then it is likely that they could have all disappeared without a trace, which would have been a real shame.  Occasionally English Heritage will also select a building because the building has played a part in the life of a famous person, or as the scene of an important event. 

In order to ensure that our heritage does not get lost in this modern World it is fundamentally important that we provide a level of protection that ensures that future generations can appreciate the built environment of their predecessors. Statutory protection and listed status allows this protection and whilst many may not approve of every building, structure or monument that is given this protection, it's importance cannot be understated.

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Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Calcium Sulphate Floor Screeds - The Problem!

Guest article from Joe Malone BSc(Hons) ICIOB

…obtaining accurate moisture measurement in the field can be fraught with difficulty and pitfalls…… You need to adopt a pragmatic approach in the field, understand the limitations of your test equipment and thoroughly review build specifications and manufacturers product information

Background

Figure 1. New development with pumped calcium sulphate floor screeds

Source: Author's Own

Malone Associates Ltd, were recently instructed by a large National developer to help resolve a dispute relating to one of their London developments. Essentially we were asked to investigate issues relating to ongoing dampness within a newly laid floor slab within a flat in a new low rise block. The history surrounding this matter was that a client had purchased the flat then noticed air blisters under the Amtico flooring in her lounge. The Amtico was taken up and a square section of the floor screed was excavated to see what was going on. My understanding was that moisture was found sat on top of the plastic resilience layer, the floor was patch repaired and further drying was being carried out and monitored until such time as readings were obtained that were low enough to justify laying the finished flooring.

We were unsure what methods of testing and monitoring was being carried out but had early concerns that the wrong type of equipment was being used. On initial enquiries as to the type of floor screed used we were informed that Calcium Sulphate floor screed has been laid, specifically a Supaflo pumped screed by Cemex. It is worth noting at this point that the terms applied to Calcium Sulphate floor screeds can get confusing because they can also be commonly referred to as ‘Calcium Sulphate screed’, ‘Gypsum’ screed or ‘Anhydrite’ screed. All three terms refer to the same generic product.

Construction - Inspection of the plans we were sent would indicate that the block is constructed of a 103mm brick outer leaf, a 100mm insulated cavity and a 140mm Metal section fully insulated frame inner leaf. With cement particle board outer, and 2 inner layers of 12.5mm plasterboard with taped joints. Importantly we could see that the floors appeared to be constructed of a 250mm  poured in-situ concrete floor slab overlaid with a 10mm resilient layer and a 45mm screed.

Site Observations - We attended site in November and after initial visual inspection assessed the flat for condensation risk. To that end the following readings were recorded. Relative humidity = 47%, Ambient air temperature 19.2^OC, Dew point temperature = 7.2^OC.  The floor temperature was recorded at 17^OC or roughly 10^OC above dew point temperature. These results proved conclusively that there was no active condensation damp problem in the flat on the day of inspection.

It could be seen on initial visual inspection of the floor screed which was stripped of finished Amtico flooring and attempts had been made to strip the screed of flooring Adhesive and primer. This is a difficult process and it was clear that there were still patchy areas of adhesive residue across the lounge floor. We also noted a large patch repair area to the floor and noted the dissimilarity between the existing screed and the repair material. 

                              Figure 2. Aggregate contained within this repair section gave concerns relating to compatibility

Source: Author's Own

It was initially assumed by site staff that the repair section was calcium sulphate and therefore compatible with the rest of the floor. When I asked for this to be confirmed the staff member who repaired the floor confirmed that it was in fact concrete and as such this repair section is incompatible with the existing floor screed  and would need to be excavated and replaced.  This is because the Tricalcium Aluminate present in ordinary Portland cement (OPC), contained within the concrete repair section, will react with the sulphate in the floor screed and cause ettringite to form. I’m sure you will all recognise this problem as Sulphate attack, which is an expansive reaction and could well lead to problems with the finished floor in the near future.

Test Methods

Figure 3. Tramex CME used for taking readings in floor screed.

Source: Author's Own

We noted the presence of a Tramex CME (Concrete Moisture Encounter) within the flat and it became apparent that floor moisture readings were being obtained by this means. This is standard industry practice because these meters are specifically calibrated for concrete and concrete floor screeds. Indeed, we use a Tramex CME ourselves but we are aware that the tool has some limitations when it comes to a reliable diagnostic process. We took electronic moisture readings across the whole of the lounge floor to obtain comparative readings and our own readings tended to confirm and support the previous statement made by the developer, to the effect that moisture levels were highest nearer the patio doors leading to the balcony. We received our highest Tramex reading of 7.5% at this point, which would tend to indicate that the floor was significantly damp. We also noted a very high Tramex reading of 6% to the concrete repair patch. We were looking to obtain readings of 0.5% total moisture content (TMC) or <=75% equilibrium relative humidity readings (ERH).

Some of the more attentive readers may have already spotted the potential problem with the use of the Tramex on a Calcium Sulphate floor screed… Did you note that I said they were calibrated specifically for concrete? Calcium sulphate is not concrete and therefore any readings obtained with the Tramex can only be referred to as a relative reading. Tramex’s own product information states that ‘The Concrete Encounter utilises “state of the art” electronic technology to provide the flooring industry with an accurate and simple to use non-invasive handheld instrument for nondestructive testing (NDT) of Moisture Content (MC) in concrete and comparative moisture readings in, gypsum and other floor screeds.’  Moreover, the Tramex is only reasonably reliable when used on virgin concrete that is clean and dust free. Once primers, adhesives and other coatings have been applied to the floor then the Tramex becomes even less reliable. The floor in question had too much surface contamination for the Tramex to ever be reliable even it was concrete as opposed to Calcium Sulphate flooring.

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Because the floor repair section was to be excavated and repaired we decided to test the floor using the calcium carbide meter. For those of you not familiar with calcium carbide testing, a small amount of test material is weighed and placed into the pressure vessel. This is then mixed with calcium carbide powder and the chemical reaction within the vessel releases acetylene gas that pressurizes the vessel and causes a reading to register on the gauge. The amount of acetylene produced is directly proportional to the amount of moisture present in the sample and this is the most reliable site test in use for establishing the moisture content of concrete and masonry products. 

Figure 4.  Repair section excavated and showing a TMC of 1.8% (Tramex showed 6%)

Source: Author's Own

The concrete repair section was indeed still damp, though this was a null point due to its excavation. We simply tested this area to complete our understanding of what moisture contents were actually present right across the floor compared to readings obtained with the Tramex CME. In fact the calcium sulphate screed proved to be bone dry with readings no higher than 0% TMC obtained. 

Figure 5. Tramex showed 7.5%, actual TMC = 0%

Source: Authors Own

We believe that the Amtico flooring was initially laid too early but subsequently after removal of the Amtico the developer has dried the floor thoroughly but been chasing their own tail due to false positive readings obtained from the Tramex.

After the floor slab was repaired we provided the client with ongoing advice for monitoring the deep repair section that was replaced but there are only three reliable ways of obtaining reliable results for moisture content in floor slabs, these are:

      1.  Calcium carbide testing

      2.  Testing equilibrium relative humidity (ERH) using Hygro sleeves.

      3.  Testing equilibrium relative humidity (ERH) using a floor humidity box.

Since options 1 & 2 involve destructive testing, then the only option available for ongoing moisture tests in the flat is option number 3. A floor humidity box should be placed on the large repair section and sealed with double-sided Butyl tape. We recommend that the humidity level inside the box is then recorded after a 72 hour period. If the ERH reading is 75% or less then you are free to proceed with the installation of finished flooring. Manufacturers information on the calcium sulphate screed used for the repair section indicated that the screed could take up to 50 days to dry so clearly an initial period of drying would be required before monitoring was started.

Ongoing Tests

The developer chose to use a ‘Tramex Hygrohood’ floor humidity box sealed in place with double sided butyl tape for ongoing moisture measurement of the repaired floor section. However this proved what we already know, in that readings of <=75% ERH are extremely difficult to achieve in floor screeds. Four weeks later I was called back to reassess the flooring after the developer failed to get ERH readings below 77%. Also you must remember that that ERH readings are relative to temperature as well as moisture yet product information makes no reference to the temperature benchmark at which the ERH reading should be taken. We generally recommend that rooms are maintained at circa 20^oC when screeds are being dried out and this is a general recommendation that is often found; it therefore makes sense to recommend that an ERH reading of <=75% should be obtained with a room temperature of 20^oC. The Hygrohood shows a reading of 77% ERH at 21.5^oC but if we drop the room temperature to 20^oC then the ERH increased to circa 80%.

The client asked if we could test with calcium carbide again and it was simply a matter of understanding what depth the latex screed could be laid to. This allowed us to take a series of shallow drillings to obtain enough material for calcium carbide testing. The test again proved that the repaired floor section was now completely dry  and the developer could move forward with installing the latex screed. The drilled areas will be made good by the latex screed.

All this proves that obtaining accurate moisture measurement in the field can be fraught with difficulty and pitfalls. Moreover, I think some of the guidance information is poor; particularly the guidance that an ERH of <=75% should be achieved, perhaps <=80% ERH would be more realistic because once that figure was achieved at a room temperature of 20^oC the floor proved to be dry. You need to adopt a pragmatic approach in the field, understand the limitations of your test equipment and thoroughly review build specifications and manufacturers product information. 

Figure 6. Tramex showing 77% ERH at 21.5oC. The repair section proved to be dry.

Source: Author's Own

Joe Malone

Director (Malone Associates Ltd)

First Published on 6/1/15 at www.buildingdefectanalysis.co.uk

Please feel free to share this article and other articles on this site with friends, family and colleagues who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Negligence – Part 3 - Defences to Negligence

In today’s extremely litigious society there will always be those who are willing to pursue a claim in negligence if they feel a professional has been negligent which has resulted in them suffering some loss or damage. Unfortunately this is the World we now live in and due to the fact that a defendant (the person accused of negligence), does not intend for the bad consequence to happen, many who are accused of negligence are likely to be surprised that they find themselves in that predicament.

Source: http://imgarcade.com/

In my two recent negligence articles (Link 1) & (Link 2) I have introduced the basic principles of the tort of negligence and discussed the ‘ingredients’ necessary to establish a claim in negligence. I have also considered the significance of this area of law to the professional person and in particular those working in Construction and the Built Environment. In today’s extremely litigious society there will always be those who are willing to pursue a claim in negligence if they feel a professional has been negligent which has resulted in them suffering some loss or damage.  Unfortunately this is the World we now live in and due to the fact that a defendant (the person accused of negligence), does not intend for the bad consequence to happen, many who are accused of negligence are likely to be surprised that they find themselves in that predicament.

In the event that someone is found to be negligent there are a number of defences in UK law that may be used to reduce or nullify any damages or compensation that can be claimed.  These defences do not remove the fact that a person has acted and has been proved to be negligent, moreover, to help them to reduce the impact and consequences of their actions.  The three defences of Contributory Negligence, Volenti non fit injuria and Ex turpi causa will be considered within this article. The latter two are Latin terms which are typical of terminology within the UK legal system which have been used over many hundreds of years and continues to be used today.  I will provide a translation for each together with the explanations below.

Source: http://www.barberandsims.com/

Contributory Negligence – This defence has been used for many years where a person who has been found to be negligent will try to prove that an injured party has contributed to their own loss or damage by their actions (or omissions).  A passenger who is injured in a road traffic collision and is not wearing a seat belt is a good example.  The driver of the vehicle may have caused the injury to the passenger and negligence may have been established, so there is no question of the driver’s negligence.  The driver however may argue that, yes, they may have acted negligently and caused the accident and the injury and loss to the passenger, however if the passenger had been wearing their seat belt then in all likelihood the injuries sustained would have been less severe.  Therefore, by not wearing the seatbelt the passenger has contributed (to the negligence) and to the extent of their injuries. These circumstances appear in the case of Froom v Butcher (1976), where the Court of Appeal reduced the amount of damages payable to the claimant by 20%.

Prior to 1945 if a person found liable in negligence could prove that the injured party had contributed to the negligence then this could negate any damages completely.  Basically the rule was all or nothing, however, in 1945 a general power to apportion damages was given to the courts by the Law Reform (Contributory Negligence) Act 1945.  This meant that as in the case of Froom v Butcher the courts have the discretion to consider the extent of contributory negligence and to award damages accordingly.

Volenti non fit injuria (‘to a willing person, no injury is done’) - If a defendant can demonstrate that the claimant (the person/party who have suffered loss, damage or injury as a result of the negligence of the defendant) voluntarily agreed to undertake the legal risk of harm at their own expense then this can negate any damages completely.  Unlike contributory negligence which allows the courts to apportion damages, volenti non fit injuria is a complete defence. When using volenti as a defence the defendant must show that the claimant acted voluntarily in the sense that they were able/capable of exercising free choice. The courts will consider the ability of a person to be able to make a free choice and therefore whether they are able/capable of making a voluntary assumption of risk.  This will be a matter of fact in each individual case and the courts will consider things such as mental capacity, alcohol and substance consumption etc.

The case of Morris v Murray (1991) is a commonly quoted case in respect of Volenti; The plaintiff (Morris) agreed to be flown by the defendant (Murray) in his light aircraft though he knew the defendant was inebriated. The plaintiff drove the car which took them to the airfield and he helped to start and refuel the aircraft, which was piloted by the friend. Shortly after take-off the aircraft crashed, killing the pilot and severely injuring the plaintiff. At first instance the court found the defendant failed in his claim of volentii non fit injuria, but the plaintiff succeeded in negligence.

Held: The defendant’s appeal was allowed. The defence of volenti non fit injuria applied, and the claim failed. The plaintiff willingly embarked upon the flight, knowing that the pilot was drunk; that the danger in embarking upon the flight was both obvious and great and the plaintiff was not so drunk as to be incapable of appreciating the nature and extent of the risk involved, and, therefore, he was to be taken to have fully accepted the risk of serious injury and implicitly discharged the pilot from liability for negligence in relation to the flying of the aircraft; and that, accordingly, the maxim volenti non fit injuria applied as a defence to the plaintiff’s claim. Source: www.swarb.co.uk

There are however statutory restrictions on the use of volenti In the case of car passengers. Section 149 of the Road Traffic Act 1988 prohibits any restriction on the driver’s liability to his passenger when required to be covered by insurance. Therefore a driver who is found to be negligent which cases injury, loss or damage to his passengers cannot use volenti as a defence.

Ex turpi causa no oritur action (‘from a dishonourable cause an action does not arise’) - A person who is injured whilst involved in a criminal act may be denied an action. In these circumstances the courts are likely to find that no duty of care is owed. The case of Ashton v Turner and Anr (1981) provides a good example; ‘The Claimant was injured when the Defendant crashed the car in which he was a passenger. The crash occurred after they both had committed a burglary and the Defendant, who had been drinking, was driving negligently in an attempt to escape. The judge dismissed the claim holding that as a matter of public policy the law would not recognise a duty of care owed by one participant in a crime to another. He held in the alternative that, even if a duty of care was owed, the Claimant had willingly accepted as his the risk of negligence and injury resulting from it’. Source: www.e-lawresources.co.uk/

UK case law is well established with many other case examples that demonstrate the application (or not) or each of the three defences discussed above.  Law can often appear unclear and complicated at first glance and I always advise my students that the most effective way of understanding the law is to research previous cases.  Anyone who wants to find out and understand more about this area of law will find that a simple internet search will provide you with all of the information you need.

Please feel free to share this article and other articles on this site with friends, family and colleagues who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.

Negligence – Part 2 – Reducing the risk of negligence claims

There are a number of areas of civil law or tort which may be considered by an ‘injured’ party such as Nuisance, Trespass and numerous others however in many cases built environment/construction professionals find themselves defending a claim in negligence.

Source: http://davidlaw.com/

In Part 1 (Link) of this article I explained how the tort of negligence is particularly relevant to the role of the built environment/construction professional and why it so important to act with professionalism, vigilance and attention to detail at all times.  The consequences of not doing this could result in a mistake/omission/error, albeit unintentionally and may lead to a loss, damage or injury occurring.  If this does happen then an action may be sought in negligence to recover the loss. There are a number of areas of civil law or tort which may be considered by an ‘injured’ party such as Nuisance, Trespass and numerous others however in many cases built environment/construction professionals find themselves defending a claim in negligence.

As also identified in Part 1 of this article; In order to assess whether a person has acted negligently the courts will consider a person’s conduct and actions against how a reasonable person would act in the same circumstances. Although important this is just one consideration in establishing negligence. Over many years through the doctrine of Judicial Precedent, case law has developed a method of establishing negligence based upon decisions made in previous cases. The landmark case of Donaghue v Stevenson (1932) established the modern version of negligence and set a precedent for the main principles of establishing negligence and ‘the neighbour test’.  It is not the purpose of this article to discuss the circumstances or detail of the case, as this is information is widely published however it is worth exploring the principles that arose from the case and how negligence is measured and proved.

Source: http://legemetevangelium.wordpress.com/

In order to establish negligence there are four main ingredients for which all need to be proved. If just one of these are missing or cannot be proved then any action in negligence will fail.  Firstly, a duty of care must be owed to the plaintiff (the ‘injured’ party) by the defendant (accused of the negligence).  Next, if a duty of care is established then it must be shown that the defendant breached this duty.  Thirdly, if the first two elements are in place then proximate cause must be established. In other words, but for the breach of duty, the injury or loss would not have happened. Finally, if all three previously discussed elements are established the plaintiff must demonstrate that the loss/injury was a reasonably foreseeable consequence of the defendant's action or inaction.

Source: https://sielearning.tafensw.edu.au

The first two elements of negligence require the establishment of a duty of care and if shown that this has been breached, but what is a duty of care? A common definition of a duty of care is: ‘A requirement that a person act toward others and the public with watchfulness, attention, caution and prudence that a reasonable person in the circumstances would. The Oxford Dictionary’s definition is a little more concise; ‘A moral or legal obligation to ensure the safety or well-being of others’. As built environment/construction professionals the understanding of duty of care and how it applies is fundamental.  If there is a contractual relationship with a Client, then any loss/damage that may occur is usually dealt with through the contract and any dispute through contract law.  If you read the details of Donaghue v Stevenson you will note that a claim for negligence can be brought in the absence of a contract, so if a Client’s claim were to be unsuccessful in contract law, they may pursue a claim in negligence instead.

As a construction professional it is always worth thinking about your activities and asking yourself if you are meeting your duty of care and acting reasonably.  The measure of reasonableness of a built environment/construction professional will be established in a number of ways. Firstly, by the standards set within an individual’s particular profession. Then, if a mistake has been made and if an appropriately qualified and experienced person taking reasonable care would not have made the mistake, then the professional person may be liable in negligence.  To establish what are reasonable standards in a profession, either the plaintiff or defendant can call an eminent practitioner to give evidence in Court as an expert witness, which is another measure of reasonableness. 

How can we reduce the risk of negligence claims? - The tort of negligence can be a legal minefield for all professionals and something that should not be underestimated.  Before undertaking any professional services it is worth establishing precisely what is expected for your fee, a robust scope of services and knowing exactly who the services are being provided for and who will be relying on your advice.  This may sound simple and obvious to many however it is these simple things that can help to avoid confusion and reduce the possibility of cutting corners and of possible negligence claims in the future. 

Underestimating a fee or confusion over the scope of services does not diminish a professional’s responsibilities in respect of duty of care, and this would certainly be a very weak defence if a claim for negligence was brought by a Client. Acting with watchfulness, attention, caution and prudence will help to avoid these types of scenario, however in the fast paced World of commerce where everything seems to be done at 100mph, sometimes working to impossible deadlines, it is easy to see how we can sometimes ‘drop the ball’. Good robust quality assurance procedures will help to identify issues/mistakes before they leave the office, however it is also worth reviewing and training staff on an ongoing basis to improve knowledge and competence, all of which will help to minimize the risk of negligence (and other) claims in the future.  How much of this are you or your organization currently doing?  Something to think about maybe?

Please feel free to share this article and other articles on this site with friends, family and colleagues who you think would be interested

Information/opinions posted on this site are the personal views of the author and should not be relied upon by any person or any third party without first seeking further professional advice. Also, please scroll down and read the copyright notice at the end of the blog.