Do All Houses Have Condensation?

Independent Building Surveyors

Our highly qualified Building Surveyors can offer you advice and help whether you are moving house or having any property issues with things such as condensation. We can provide a comprehensive survey report on a building whether it is commercial or residential. We do Specific Defects Reports on such things as chimney problems, dampness, cracking, condensation and much more. We can also carry out Independent Valuations but please note these are not for bank lending but are to advise you how much we feel the property is really worth.

Please free phone us on 0800 298 5424 for a friendly chat. All our surveyors are independent which means they are not attached to any estate agents, bank or building society. When working for you they solely have you best interests at heart.


Do all houses cause condensation it is just that we cannot see it as it is hidden in the walls?

For those of you that live in old houses, which are the majority of people, by this we mean prior to the War years, these houses usually have solid walls, typically Flemish bond wall construction and for those that live in houses later than this typically they will have cavity walls. More modern properties have insulated cavity walls and more modern properties still have insulated cavity walls with dry lining insulation inside which often also has insulation.

Our question is what is going on inside the walls?

Is condensation occurring, this is known as interstitial condensation where we are just storing up problems for years to come, with the mould that occurs and the associated health problems is it equivalent to asbestos ?


Cavity tray example

Condensation and Black Mould

Rising damp and penetrating damp or lateral damp or leaking gutters or roof leaks or flat roofs leaking and/or rotting timber windows often get the blame for what is correctly diagnosed as condensation. Condensation occurs when the water content of the air is discharged when it meets a cold surface, you can see the phenomena when in a bathroom where the mirror steams up or equally it is when we get dew in the grass.


Sketch of dry lining

How much water is in the air?

It is generally estimated that specific moisture generating activities such as:

one person asleep generates half a pint

one person active generates a pint

having a bath or a shower can add two pints,

washing dishes can add a further two pints and

two people at home during a typical weekend will add three pints (three pints on Saturday and three pints on Sunday if you do not take a shower or bath!).


The things that create larger volumes of water are bottled gas heaters which after they have been used for a day created about four pints, the use of kettles creates six pints, drying clothes indoors created nine pints and we suspect that all these figures vary according to the frequency of the activity such as the length of time and the amount of clothes drying indoors which certainly varies from family to family dependent upon the number of children and the children's ages etc.

This combination of moisture can often be balanced by using ventilation such as airing the house by opening windows in the morning which seems to have gone out of fashion to trickle vents being on double glazed windows to older timber windows literally having gaps around them which help vent the house. Even such things as a real fire will aid air movement so it really is a matter of bringing all these things together as well as the heating and cooling of the house.

Condensation is visible in older properties (on the walls although it is often wrongly diagnosed)

Condensation in older properties can be seen in the form of damp patches on walls, often these are relatively random or it is interesting how often people attribute them to something such as a leaking roof. They can often be seen in the form of black mould which is a mixture of dust particles that are in the air getting carried by the moist air to the colder walls where it discharges. This can grow as a mould when fed by such things as particles of skin that we discharge naturally which are also carried in the air.

An example we were recently involved with within a block of 1970s apartments they were three storey with an apartment on the ground floor and then apartments taking up the first and second floors. The construction was what is known as cross wall construction which is a form of construction which was common and popular in the 1970s where the weight of the property is taken on two of the outer walls, the front and the back being little more than a cladding. In this case in addition to that concrete floors had been used throughout and concrete lintels. The property we looked at was suffering badly from condensation in all the rooms occupied by a family with two children and was fairly average with the exception of the amount of condensation in it. We carried out tests and investigations and it was discovered that the concrete floors were part of the concrete frame structure which what had looked like cross wall construction was not cross wall construction at all and there were concrete lintels present. These relatively cold elements of concrete in a warmer structure were causing condensation to occur around the windows resulting in a black mould problem. Whilst the owners said they regularly cleaned the mould off the windows they were not having any success solving the problem.

Solving condensation can be very difficult

Often condensation is a combination of issues and the property needs to be looked at as a whole so it can seem an almost impossible problem to solve when you are told in leaflets for example that it is just as simple as turning up the heating or adding extract ventilation.


Are we creating condensation in the cavities of modern properties?

condensationWhat we would like to say is that condensation on older properties can be seen and therefore it can be dealt with. However within modern properties condensation is often hidden behind the surface of the structure and is occurring within the walls, this is known as interstitial condensation. What damage is this interstitial condensation doing to the wall, will mould grow within the porous structure of the bricks for example or the inner walls of the cavity or inside the dry lining? What sort of long term health hazard will develop from this if any?

How can we investigate if there are problems?

We have over the years investigated problems in cavity walls in a variety of ways from thermal imaging to endoscopes which allow you by drilling into the wall to view through a flexible fibre optic cable although in our experience the view has been relatively limited (original application was for surgery). If you go to Youtube and type endoscope or borendoscope then you will see plenty of examples of the limited view you will get. It is also worth looking at the video wall ties; guaranteed a waste of money!

The ultimate way, which is what we prefer, is to literally open up the wall itself admittedly this not always possible.


Thermal image photo

Compare our Building Surveys but don't compare Apples with Thursdays

We have a wealth of knowledge and experience as independent surveyors if you require a building survey or structural survey.

We have surveyed many types of property from traditional Tudor residential properties to large warehouses and are more than happy to email you example surveys. Please call us on 0800 298 5424.

We have every confidence in our surveys and believe there are no other comparable surveys out there in the UK property and surveying market.

A photo is worth a thousand words particularly in a structural survey

As you can see from this article we use lots of sketches in our reports as the feedback we have from our clients is that the sketches that we use help them understand our reports better and in turn their better understanding ensures that they know the problems or issues that the property has and as such they can negotiate with regards to price on this matter or make allowances and budget for future work.

We also use many photos in our reports like the example to the right.

We are more than happy to meet you at the property during the survey to discuss any issues you have and we are more than happy to walk around the property and show you our findings. Please free phone 0800 298 5424 for a friendly chat with one of our surveyors.


What do our circles and ovals mean on our photos and sketches?

We use circles and ovals on our photographs and sketches like the example shown here to emphasise problem areas so that you are not left wondering what the problem is.


An example of one of our photos

Independent Surveyors

If you truly do want an independent expert opinion from a surveyor with regard to valuations, mortgages, mortgage companies, surveys, building surveys, structural reports, engineers reports, specific defects report, structural surveys, home buyers reports or any other property matters please contact 0800 298 5424 for a surveyor to give you a call back.

Commercial property surveyors

If you have a commercial property, be it leasehold or freehold, then you may wish to look at our Dilapidations Website at and for Disputes go to our Disputes Help site .

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