Subsidence – Part 1 – Not all it’s cracked up to be!

When you see cracking in a building it will not always be, in-fact is unlikely to be subsidence. This can only be established through a comprehensive building survey and detailed investigations

Source: Simply Business

As a Building Surveyor, when inspecting buildings I have learned over the years to be very cautious in the terminology I use in the presence of Clients because there are some words that just provoke panic. Take asbestos for example, or cracking or even subsidence. These words strike fear into many people mainly as a result of what they have seen in the news or read in the media. It is fair to say that sometimes these fears can be realised if any of the above examples are found to be present/occurring in a building, however in the vast majority of cases, these issues can be dealt with relatively easily. This is generally a result of a lack of real understanding, which is why it is always advisable to seek professional advice from a Building Surveyor or other relevant professionals.

When I first graduated from University I joined a Property Consultancy who’s main area of business was dealing with subsidence insurance claims as Loss Adjusters. My role was to visit site with a more experienced Structural Engineer, who would make an initial assessment, and then I would be required to manage the claim to a conclusion. This often involved crack monitoring to establish whether any movement was historic (had now stopped) or progressive (was still continuing). This was a crucial part of the process as it is pointless dealing with the effect of subsidence until movement has been stopped. On the occasions where movement was found to be progressive, it was sometimes first necessary to undertake substantial remedial work such as underpinning to stabilise the building. In these instances, the whole process could be lengthy and disruptive for the residents and in some cases required temporarily decanting of the occupants to alternative accommodation for the duration of the works. Most home insurance policies will cover subsidence risk and incorporate an excess payment in the region of £1000 (always check the wording of your policy because there can be variations). This demonstrates that the effects of subsidence can be disruptive and even though it may be covered by home insurance it can still be expensive.

Source: own

The above scenario provides an example of what can happen at one end of the scale, however as already stated the vast majority of subsidence claims I managed were dealt with quickly and with minimal disruption, many proving not to be subsidence at all. When undertaking building surveys, a Surveyor will not just identify where and why subsidence has occurred, but also look for indicators that may contribute to subsidence in the future. Before providing you with details of what I would look for during a survey (this will be provided in part 2 of the article), I think it is important to first understand exactly what subsidence actually is.

Building design should involve careful consideration of the type/load of the building, the type of foundation used and ground bearing capacity and nature of the ground, the height of the water table and so on. These types of investigations should help to ensure that once the building is complete and occupied that it does not move!  Subsidence however is not the same as settlement. Settlement usually occurs in new or relatively new buildings. As buildings are very heavy they cause the ground to compact, although this will usually stop after a short period of time.  Also, most buildings are constructed in a variety of materials, all of which need to settle and in addition will have different rates of shrinkage.  Subsidence occurs when for some reason the load bearing capacity of the ground that a building is placed upon is no longer capable of accommodating that load. The reasons for the change is the load bearing capacity is impacted and this can occur for many different reasons and in some cases, many years after the building was first completed. It is quite feasible for a building to sit quite happily on a piece of ground for many years and due to some of the influences discussed it part 2 of this article, it can start to move.

Cracking in buildings occurs for many different reasons so it is fundamentally important that anyone who undertakes inspections or gives advice in respect of cracking should not make rash judgements and should gather all of the evidence before arriving at a possible cause. In order to aid the inspector, which as stated previously, can be a Building Surveyor, it might be necessary to recommend other investigations such as geo-technical surveys to establish ground type, composition, contaminants etc., trial holes to establish foundation depths, CCTV inspection of the drainage system and possibly an arboricultural survey to give advice on any trees that may be an influencing factor. The choice of which investigations are needed will be decided once the inspector has made an initial assessment of the cracking.  Therefore, when you see cracking in a building it will not always be, in-fact is unlikely to be subsidence however, this can only be established through a comprehensive building survey and detailed investigations.

In Part 2 of this article I will discuss subsidence in more detail and provide information of the things a Building Surveyor will look at to identify when and how subsidence is occurring as well as indicators that may suggest that subsidence can occur in the future.


Author: Gary O’Neill

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Stock Condition Surveys - Part 2 – A Consultant’s perspective

Above all, the success of a stock condition survey will be down to good organisation, management and leadership

Source: Spilled News

In my last article I discussed various reasons that may motivate a Client into undertaking a stock condition survey and identified a number of key factors that need to be considered prior to engaging a Consultant for delivery of the surveys.  In this article, after a brief explanation of how data capture has evolved over recent years, I want to view things from ‘the other side of the fence’ and discuss issues that a Consultant may encounter in both the pre and survey stages.

A short history of data capture

Over recent years technology had moved on at a rapid pace and there are now numerous hardware choices and software packages on the market that enable Surveyors to carry out surveys ‘remotely and in real time’. I have been lucky enough to be involved in stock condition surveys over the last 20 years, which initially were all undertaken on site by hand, usually with a pre-prepared proforma. This then developed into the first iteration of electronic data capture in the form Psion handheld’s. These were large ‘bulky’ pieces of equipment which were difficult to navigate through and were extremely limited in their capacity to store data. At the end of each day it was necessary to upload the information from the handheld via a docking station, which often led to ‘technical issues’ which sometimes resulted in data being lost.  As you can imagine this was very frustrating.  Battery life was also an issue, where it was necessary for us to take back up battery packs to allow us to stay on site for a full day. As technology advanced we started trialling on site data collection with smaller and slimmer PDA’s and Palm Pilots.  In the early days these were extremely ‘sluggish’ on site, as the capacity to store data was often limited. I can remember that one of my clients had produced a proforma that required recording of so many attributes that the PDA became unusable. We had to recommend a significant re-drafting of the proforma in order to be able to continue with the survey. Nowadays tablet’s have emerged as the new way of collecting on site data. These have built in camera’s, have much larger built in memories, are light weight and can offer unparalleled back up facilities. With a number of specialist stock survey software packages available we now have both hardware and software to make the whole process faster and more efficient. In addition, Cloud based technologies continue to evolve and these have significantly impacted on data storage and usability of data. It is however worth stating that however advanced hardware and software may become, the accuracy and value of the data will always be relative to the knowledge and expertise of the Surveyor.

Source: Journal for Clinical Studies

Pre-survey stage

It is highly unlikely that the cost of a stock condition survey will exceed OJEU thresholds (although after Brexit OJEU is unlikely to be an issue) therefore the content of a tender submission will be down to the requirements of each individual Client. At this stage it is vitally important to read the tender documents thoroughly to establish the scope of the survey and therefore assess the resources that will be needed to deliver what the client is expecting. Although very significant, resources will not just relate to the survey team.  Purchasing hardware and obtaining software licences can be extremely expensive which if not adequately considered could significantly reduce the profitability for the Consultant. Also, a Client may have their own in-house Asset Management system and if so are likely to require data collected during a stock condition survey to be compatible with their system. There are numerous examples of asset management software such as Orchard or Atrium to name a few, however a Consultant will need to become familiar with a Client’s particular system, which will involve consultation and possible training. In fact establishing a Client’s existing asset management processes and systems is fundamental to helping a Consultant to deliver a successful stock condition survey.

The deadline is also fundamentally important in planning the survey and also for fee calculation. A delivery programme should be formulated at the earliest possibly opportunity, working back from the Client’s deadline. The programme should include all pre and post survey activities including consultation with the Client; planning, pilot surveys, training of staff, arranging access, on site surveys, quality assurance checks, moderation and validation, reporting, etc. The amount of inspections that are required (which will be determined by the target sample size) will determine how many surveyors will be needed. It may be that during the preparation of the programme that a Consultant will realise they will need more surveyors than they first thought in order to achieve the deadline. This will subsequently impact on the amount of hardware and software licences that are needed and therefore the fee that is likely to be charged. 

Survey stage

Once a Consultant has been awarded a contract to deliver a stock condition survey there are number of things that can be done to ensure that the deadline is met and that the data collected in accurate and consistent:

Good leadership – It is extremely important that a Consultant appoints an experienced member of staff to oversee and take charge of the stock survey, right through to completion. Ideally, this individual should have been involved in the tender process and therefore understand the Client’s requirements; be able to manage a large team of surveyors and be able to incorporate and manage a robust quality assurance system and act as liaison with the Client. A Consultant should never underestimate the complexity of delivering a stock condition survey and unless a suitable ‘leader’ is appointed to manage the project, then the whole process can become chaotic and poorly managed and will ultimately result in failure.

Training – Quality of data and consistency are important in ensuring that the data can be confidently used in the future for a variety of different things.  Achieving this however is always one of the biggest challenges a Consultant will face and one of the biggest frustrations that a Client will encounter if the information received is of poor quality.  The problem with undertaking any inspection is that different surveyors could inspect exactly the same building but actually produce a different assessment of an element or an attribute.  This is human nature and although impossible to avoid, it is possible to manage.  What a Consultant should be trying to achieve is for Surveyors to be looking at elements/attributes in the same way and although they may not arrive at identical assessments, they should be very similar.

Prior to letting my Surveyors undertake the onsite surveys I would give then lots of information which would include definitions of physical condition, priority, user effect and risk rating etc. (This would vary from survey to survey, depending on the Client brief). The table below provides an example of typical definitions that could be used:

I would then arrange a half day workshop with the whole survey team, where amongst other things we would discuss the definitions and use examples to assess how individual Surveyors would consider a particular element/attribute. During this meeting we would also discuss and use the hardware/software that was going to be used for data collection, discuss access issues, time frames and the quality assurance procedure. These types of meeting are invaluable as it gives the survey team the opportunity to understand what is expected and provide an opportunity to raise any questions they may have.

Quality Assurance Procedures – As discussed throughout this article, quality assurance processes are an extremely important part of the whole process.  When managing large condition surveys I would spend a few days out on site with each member of the survey team during the first few weeks of the survey. This enabled my Surveyors to ‘iron out’ any uncertainties whilst I was present and to ask further questions as needed.  When the data was uploaded I was able to view this through the relevant asset management database and I was able to add filters so that I could generate numerous reports throughout the whole time that the data was being collected.  I was then able to question things that appeared to have been missed where data fields were empty, or ask questions where surveyors had identified high priority issues etc.  This enabled data to be corrected where necessary and sometimes identified surveyors who I needed to spend more time with who clearly required more training.

To consider every aspect of a stock condition survey in such a short article would be impossible.  Hopefully, I have discussed some interesting aspects of what can be a complex process to manage and deliver.  Above all, the success of a stock condition survey will be down to good organisation, management and leadership which will incorporate all of the various aspects I have discussed above.  Once the process is set up and organised correctly the data collection is usually reasonably straightforward. In order for this to be achieved there needs to be a great deal of planning and consultation many months before the data is collected onsite, if this is not undertaken then a Consultant is likely to encounter serious difficulties in meeting the expectations of their Client

Author: Gary O’Neill

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Stock Condition Surveys – Part 1 - A Client’s Perspective

Many Client organisations will not have the skills and resources available in-house and will therefore use external consultants for delivery of stock condition surveys due to their scale and complexity. The choice of consultant is fundamentally important to the success of the survey and clients should be very thorough in their selection and procurement processes

Source: Black Cat Building Surveys Ltd

For many years in my professional career I was responsible for advising, organising and managing numerous large stock condition surveys for a range of Local Authorities and Social Housing Providers. The prime motivation for the stock survey usually revolved around stock transfer, strategic planning related to asset management and business plans, or in the case of schools to follow a prescribed method such as the Department for Education and Skills Asset Management Strategy (now the Department for Education). My initial involvement would always involve helping each of the various clients to understand what they wanted (in most cases there was a lack of real understanding of was required), to set the scope of the surveys, to manage and co-ordinate large survey teams and to present the data in an understandable and usable way.

If you are currently planning for a stock condition survey or maybe you already have one in progress, then there are many different things you need to consider in order to try to ensure that the data collected and indeed the outputs are actually what you intend. I can think of numerous examples where Clients have had difficulty in managing/coping with the vast amount of data that is produced, and once received, they were not exactly sure what to do with it. Over recent years, technology has gone some way to addressing this as data can be collected and collated in ‘real time’ and there are a range of ‘off the shelf’ software packages that will analyse the data and produce all sorts of reports and charts, which are useful as long as the Client knows their output requirements. Therefore, a successful stock survey requires many months of planning and organising.  From a Client organisation perspective there needs to be well organised strategic approach establishing precisely what is required and importantly how this will be achieved. The information below identifies some key issues which should be considered:

Source: Homebuying Guide

What is the purpose of the Stock Survey? - A very simple question which often produces a variety of different answers. The answer to this will actually set the scope of the survey and will decide the outputs that are required so if there is a lack of clarity at this point then the whole process becomes confused. Therefore will the data be used to plan future work packages, if so, over what period of time? Will the data be used for strategic planning and be incorporated into a business plan? or maybe assessing current and future repairs and maintenance liabilities or consider statutory compliance or possibly a combination of these. These examples are not exhaustive, however demonstrate the wide range of possibilities that a stock condition survey could be used to achieve. It is only possible to move onto the next stage of the process once a Client/organisation can provide a clear answer to this question. Only then is it possible to start to look at the scope of the survey, the attributes to be recorded, the sample size (will this involve cloning?), the required outputs, deadlines and also the available budget (for the condition survey).

I remember one particular organisation I was advising, a Local Authority, who required a stock condition survey for their commercial building stock. This included a range of buildings such as community centres, libraries, leisure centres, offices and numerous other public buildings. In total this amounted to approximately 400 different buildings, so not a large stock survey, but challenging due to the diversity of the building stock. I became involved at a very early stage and it soon became clear that there were differences of opinion in respect of what was required to be achieved within the client organisation itself. One particular senior manager was insistent that the data collected should be used for strategic asset planning and also to assist much lower cost day to day maintenance. This manager was adamant that the survey should record things like door handles, hinges, taps, plugs, sealant etc. therefore taking the required attributes to a ‘micro level’. I highlighted the consequences of this approach in terms of the high cost of each survey due to the amount of time the surveyor would be on site, the difficulty in consistency of recorded information if you provide surveyors with too many choices, and also the limitations of the hardware at the time. In the end I was able to steer this particular client down a much more sensible road however this demonstrates some of the challenges that may be encountered, through lack of understanding and differences of opinion.

Choosing the right people - Many Client organisations will not have the skills and resources available in-house and will therefore use external consultants for delivery of stock condition surveys due to their scale and complexity. The choice of consultant is fundamentally important to the success of the survey and clients should be very thorough in their selection and procurement processes. Many consultants advertise their experience and skills in delivery of stock condition surveys, however there are some important factors that should be considered when selecting consultants for this type of work:

Resources – Based upon what you have detailed in your brief, what resources will the consultant provide to the project to ensure that the data collected will be appropriate and consistent and also achieve the deadline that you have set?  It is important to find out precisely who will be carrying out the surveys (ask for CV’s), and who will be responsible for managing/overseeing the survey. Consultants will usually calculate their fee based upon the amount of time they are likely to spend on the project and the level of staff that will be needed. For large stock surveys what tends to happen is that less experienced staff (newly qualified, or those undertaking professional qualification such as APC), are used for the bulk of the surveys and a more senior member of staff is used to oversee the project. This can work as long as the senior member of staff, undertakes robust quality assurance checks of the data being collected and undertakes continual training throughout the process with the surveyors to try to achieve consistency. The whole process can easily break down if a Consultant does not manage the process in this way and will lead to incorrect/inconsistent data being collected. This should never be allowed to happen and is something that a Client should explore during the procurement process.

Procurement – All Clients will have a budget available for a stock survey and in fact this is something that helps define the scope of the survey. If you want a Consultant to understand what you require, and you want a fee that is reflective of the services that they will provide then you must ensure that your brief is suitably detailed and clear. This probably sounds obvious, however I have prepared endless tenders for many different types of work, where the briefs provided are so vague or poorly written that it is difficult to understand exactly what the Client is looking for making reflective fee calculations very difficult.

Prior to tendering for the ‘main’ stock survey, my advice would be to invite a number of Consultants to tender for a ‘pilot survey’. This will enable each Consultant to demonstrate their resources and capabilities for a small number of surveys, as well as finding out what works, or maybe does not work, before ploughing on with the bulk of the surveys. This exercise could form the first part of the selection process, which should also be preceded by Consultant interviews. This may sound like a lengthy process; however, it is extremely important to appoint the right Consultant. This approach may well reduce the possibility of serious issues arising either during the survey process or when you come to rely on the data that has been collected.

Consultant’s Fee – Always analyse precisely what the Consultant has included with their fee.  If your tender documentation, including your survey brief are sufficiently detailed then the Consultant should have provided a fee to reflect what you have asked for. If not, and the Consultant has included their own ‘inclusions or interpretations’ then this will make the fee very difficult to compare with other tenders. This should not happen, as this could invalidate a tender, depending upon the method in which tenders were issued. In any event there needs to be a detailed tender analysis in order for a Client to satisfy themselves that the Consultant can provide precisely what they want for the fee they have provided. Never be tempted to look at the headline fee alone, as without looking you cannot know what (or what is not) included within that fee.

In my next article I will consider stock condition surveys from a Consultant’s viewpoint and provide some examples of how I used to manage large stock surveys.


Author: Gary O’Neill

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.

Damp in Buildings – Part 2 – Condensation – How to reduce the risk!

There are a few very simple, but nevertheless very effective ways we can reduce the risk of condensation, just by simply being aware of some of the activities we would normally undertake without even thinking

Source: Homebuilding & Renovating

In order to understand how to reduce the risk of condensation it is important to first understand how it occurs. If you have not already done so I would recommend reading last week’s article, ‘How condensation occurs’, before going any further. You will then understand that the ‘ingredients’ necessary for condensation to occur are moisture vapour and cool surfaces, which are exacerbated by poor insulation, poor heating and poor ventilation. Cool surfaces could be present due to thermally inefficient walls and surfaces, particularly in older buildings. In fact there are a whole host of reasons why the internal surface temperature of the internal fabric of a building may be cool (walls, windows, ceilings etc.,) including poor maintenance of external walls, rising damp, penetrating damp due to leaking rainwater guttering or downpipes, leaking roofs, single glazed windows, poor weather sealing around openings and cold bridges, which are areas of the building fabric which are less thermally efficient than the surrounding construction.

To reduce the risk of condensation occurring there are two primary things we should consider. Firstly, dealing with the root cause of the condensation and secondly, looking at the way we use a building and trying to find ways of reducing the amount of moisture vapour we emit.

Source: Home Guides - SFGate

In order to rectify the problem, we first need to establish the cause. This is where you may need the advice of a Building Surveyor, who will be able to undertake a thorough inspection and establish which factors or combination of factors are contributing to the condensation. This is important because if you do not deal with ALL of the contributing factors, you may slow down the amount of condensation occurring, however you will not actually solve the problem.  For example you may decide to improve the heating system, but if you do not deal with the thermally inefficient walls, then all of that increased heat will just disappear through the walls, and will have a limited effect.  So depending on what is established as the cause, it may be necessary to increase the internal surface temperature of the walls by either insulating internally (dry lining) or externally (insulated render system), replacing windows (possibly double or triple glazing), improving ventilation (possibly a mechanical extractor fan) and upgrading the heating system. As you would imagine, this could become very expensive, which highlights why you may need the advice of a professional to ensure that the correct remedial measures are undertaken. All buildings are different and the way we use buildings will also be different, therefore we cannot assume that the cause of condensation and the remedial works required will be the same in every situation.

After dealing with the building itself we must also consider ways in which we can reduce the amount of moisture vapour we emit in buildings. Yes, our human behaviour can have a significant impact on reducing moisture vapour in a building. If we start to think about ways in which we use and occupy our buildings and either do thinks in different ways, or even stop doing them completely, we can significantly reduce the risk of condensation. The best thing of all is that a change of behaviour is absolutely free! There are a few very simple, but nevertheless very effective ways we can achieve this, just by simply being aware of some of the activities we would normally undertake without even thinking.

Showering/bathing, Washing and Cooking are activities that we cannot avoid however all produce large amounts of moisture vapour.  We undertake these activities on a day to day basis, however when showering/bathing, try to not leave the shower or bath taps running more than you need, switch them off as soon as you can. If you have extractor fans, ensure that they are working, adequately sized and switched on when needed. You should also ensure that trickle vents in windows are open and that air bricks are not blocked. Although it may be cold outside, when you are leaving the bathroom, open the window to let fresh air in, which will soon clear the moisture vapour by replacing the moisture laden air with new fresher dryer air which will prevent moisture vapour condensing on the walls and windows.

Source: Maxzi

If you are using a Tumble Dryer, ensure that it is vented to the outside. I have undertaken a number of previous inspections where I have seen the flexible tumble dryer vents extracting into a room, rather than outside. This was due to lack of thought of the location of the tumble dryer and a general lack of understanding on the part of the occupiers. Also, when Drying Clothes try to avoid placing them on top of radiators. This is usually done for convenience, however again produces large amounts of moisture vapour. Whenever possible washing should be dried outside, or if weather conditions do not permit this then consider using an appropriately vented tumble dryer, or maybe even a trip to the launderette.

When Cooking use an extractor hood if you have one above your cooker and keep lids on saucepans as much as you can.  Avoid using Bottled Gas and Paraffin Heaters these produce large amounts of moisture vapour.

Finally, but very importantly, try to ensure you have a regular flow of fresh air around your house/buildings. This effectively dries out any moisture vapour and prevents it reaching concentration levels where condensation may become an issue.  Granted, nobody wants to release all of that lovely heat from a building in the depths of winter, however, opening windows for a short period of time may result in the internal environment becoming temporarily cooler, but it will also significantly help to reduce the risk of condensation.

Hopefully, now that you know how condensation occurs you can start to thing about ways in which you can help to reduce the risk. In future articles I will discuss other forms of damp in buildings such as rising damp and penetrating damp.

Author: Gary O'Neill

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.

Damp in Buildings – Part 1 – Condensation – How it Occurs

If left untreated condensation can become a significant problem so it is important that people understand how it occurs and how to deal with it. Due to the fact that condensation produces water/moisture it can also act as a catalyst for a number of other defects that can be found in buildings

Source: Bob's Heating & Air Conditioning

Most people will have seen damp in their homes in one form or another, and in fact damp is one of the most common problems encountered in houses.  Damp can manifest itself in a number of ways including ‘wet patches’ on surfaces, mould growth and sometimes a musty smell.  If left untreated damp can lead to deterioration of internal surfaces and finishes, provide a very unsightly appearance and in certain circumstances lead to health problems, particularly for vulnerable user groups such as the elderly, young children and those with respiratory conditions such as asthma.  There are a number of different types of damp that can occur in buildings including rising damp and penetrating damp, however for the purposes of this article I want to focus on condensation. 

In order to understand how we can deal with condensation it is important to first understand how it occurs.  All air contains a certain amount of ‘invisible’ water vapour. You may not realise it, but as a human beings we are emitting water vapour constantly, you may not see it but it really is happening. Water vapour is also emitted by the activities we undertake in the home including washing, cooking, drying clothes, using portable heaters such as calor gas etc.  Basically, there are large volumes of water vapour being emitted in your home and the amount of water vapour that is emitted is determined by the activities that we carry out and the number of people in your house at any particular time.  Condensation occurs when this water vapour comes into contact with cooler surfaces and the air no longer has the capacity to hold any more water vapour. In order to understand this we need to first understand relative humidity, which is a generally poorly understood term.

Source: Own

Relative humidity relates to the actual water vapour present in air to that which could be present and is routinely expressed as a percentage. The reason we refer to ‘relative’ humidity is because air has a varying ability to hold moisture vapour depending on temperature. Warm air can hold more water vapour than cold air. Once relative humidity reaches 100% it no longer has the ability to hold any more water vapour and it will start to condense on cooler surfaces (something referred to as ‘Dew Point’), which is the physical change into a liquid (condensation). 

As an example, think about your bathroom. When you have a bath or shower, large quantities of water vapour are produced.  Sometimes this will develop into a ‘fog/mist’ in the room until you open the window or turn on an extractor fan.  Have you ever noticed that you get water developing on your windows and walls? This is condensation. Have you ever wondered why this happens more readily on cold days, and in the warmer months it is hardly noticeable?  This is because the air in your bathroom on colder days has less capacity to hold moisture than the air in your bathroom during warmer temperatures (remember warm air can hold more water vapour than cold air). Windows, particularly in older buildings are generally less thermally efficient than the surrounding structure such as the walls. Therefore the internal surface temperature of the windows will be a few degrees cooler than the surface temperature of the walls.  This will mean that once dew point occurs (100% relative humidity), it will start to condense on the cooler surfaces first, i.e the windows, before it starts to condense on the surrounding walls.

Condensation can occur in any room in a house or within the structure of a house (interstitial condensation), including roof and floor voids, basically anywhere, where there is water vapour and cool surfaces. If left untreated condensation can become a significant problem so it is important that people understand how it occurs and how to deal with it. Due to the fact that condensation produces water/moisture it can also act as a catalyst for a number of other defects that can be found in buildings, namely timber decay such as wet rot or dry rot, as well as causing mould growth and potential health problems. 

You do not need to be a damp specialist or a building surveyor to be able to deal with condensation or at least reduce the risk of it occurring. There are numerous products on the market that claim to reduce or remove the risk of condensation in homes including paints and sprays.  These types of products may temporarily remove condensation mould that may have already occurred, or cover over damp mould, however the only certain way of removing the risk of condensation is to understand the root cause, which will vary from building to building, and to rectify these root causes.  The usual factors that result in condensation are poor thermal insulation, inadequate heating, inadequate ventilation and crucially, the way in which we use our homes, or a combination of these. In the next article I will explain how you can reduce the possibility of condensation in your home and if you already have problems with condensation I will tell you how to deal with it.

Author: Gary O'Neill

Please feel free to share this article and other articles on this site with colleagues, friends and family.

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.