Drains play a crucial role in keepings buildings free from damp issues, ensuring wastewater and stormwater flows away efficiently. However, hidden issues within drainage systems can lead to a nightmare scenario – rising damp. In this blog post, we’ll explore the significance of drain cameras and how a drain camera survey can be a game-changer in safeguarding buildings from rising damp in the UK.
1. Identifying Hidden Problems:
One of the primary reasons to have a drain camera survey is its ability to reveal hidden problems within the drainage system. Over time, drains can deteriorate, become blocked, or develop cracks, leading to leaks that allow moisture to seep into walls and floors, causing rising damp. A drain camera survey can help detect these issues early, preventing potential damage to the building.
2. Non-Intrusive and Cost-Effective:
Unlike traditional methods that may involve digging up the ground or dismantling parts of the building, drain cameras offer a non-intrusive solution to inspect drains. This significantly reduces disruption and keeps costs in check. Detecting problems at an early stage through a drain camera survey can save building owners from costly repairs in the long run.
3. Enhanced Accuracy and Efficiency:
Drain camera technology has evolved over the years, providing enhanced accuracy and efficiency in detecting drain issues. The high-resolution cameras we use can capture clear images and videos of the inside walls of the drains, enabling us to pinpoint the exact location and nature of the problem. This precision helps in devising targeted solutions, minimizing guesswork and unnecessary repairs.
4. Prevention of Rising Damp:
Rising damp occurs when water from the ground is drawn up through capillary action into the building’s walls, causing structural and aesthetic damage. Faulty drains and leaks can exacerbate this issue by introducing additional moisture into the building’s fabric. A drain camera survey allows for timely detection and repair of drainage issues, preventing rising damp and its associated problems.
5. Can Drain Surveys prevent Damp:
Having a drain survey can help identify such drainage problems and ensure that all water is adequately directed away from the property, reducing the risk of rising damp. So, in a preventive sense, a drain survey can indirectly contribute to mitigating rising damp issues by addressing drainage concerns.
6. British Standards BS 6576
It is mentioned in the British Standards BS 6576 Code of practice for diagnosis of rising damp in walls of buildings and installation of chemical damp-proof course states, particular attention should be paid to faulty drains before coming to a conclusion.
Investing in a drain camera survey is a wise decision for property owners. By identifying hidden drain issues and preventing rising damp, it can save them from potential headaches and substantial expenses down the line. Embracing this modern inspection technology not only protects the building but also ensures a damp free environment for occupants, and has the potential to save thousands of pounds on unnecessary repairs.
Joint position statement, 1st edition, September 2022, 1st edition, September 2022
Finally after the first joint draft methodology was published in 2019, this was launched at the International Property Care Conference.
What is really great is that finally everybody is talking, and this joint position statement will hopefully help everybody progress in offering more detailed damp investigations/diagnosis, and the consumer should receive better advice in regards to damp issues, and advice on any repairs where necessary.
See my thoughts at the end, and some images of the conference.
Personally from experience I still think it will still be a struggle to get the consumer to pay for a thorough damp investigation, that eliminates everything that could be causing excess moisture to the property. The next issue is when a property is being sold, the vendor will still not allow an invasive or disruptive damp investigation to take place……This then makes it very difficult to determine the cause and work out the costs of any repairs.
If you need a damp investigation this and other British Standards, guidance notes make it clear that a thorough investigation needs to take place eliminating potential issues before coming a conclusion, and offering damp repair advice.
I personally like the below part which is from the British Standard BS 6576:2005. All other possible causes of damp conditions should be located.
Particular attention should be paid to: a) condensation; b) lateral penetration associated with changes of floor/ground level; c) leaks from roofs, gutters and downpipes; d) faulty drains; e) internal plumbing leaks; f) water penetration through external walls; g) water penetration around window frames and doors; h) mortar droppings or debris in cavity walls; i) history of flooding.
The above is really what is to be expected from an averagely competent damp specialist to find the root cause of damp. Once the defects/issues have been found, really only then can a specification of repair be offered. Personally I only offer invasive damp investigations so I can be sure that I can find the root cause when carrying out the initial survey, and then anything can be clarified using in house gravimetric analysis, and hygroscopic salt analysis. Make sure if you have been offered a damp survey, you get in writing exactly what they will and won’t be doing, so you know what you will be getting for your money. It is common practice for people to pay for a damp survey, only to find out afterwards that its a non invasive/disruptive type, and in the report they receive it then offers an invasive/disruptive survey and any sampling subject to additional costs, and then recommends further CCTV drain surveys, and leak detection surveys. These are the types of cheap worthless surveys that offer no diagnosis, and not recommended in the Investigation of moisture and its effects on traditional buildings.
Here are some images from the conference in regards to my presentation.
What I have found is that many people don’t know how land was drained around a building, and that sub soil / land drains were used to essentially help to prevent rising damp as stated in the Byelaws. Unfortunately trying to determine if you have any form of land drainage that is blocked is pretty much impossible. The only way to find them, or see if you have any sub soil drainage without digging up the complete garden is to use ground penetrating radar. Ground penetrating radar surveys will find all forms of below ground drainage to include land drains, french drains, sub soil drainage, culverts, wells, and even cisterns. It isn’t unusual though that whilst your building didn’t have any form of land drainage installed originally, that somebody has installed some from of modern drainage like a French drain. I’ve lost count of the amount of these i’ve found where the building is absolutely saturated, and know body can work out why. Again, it comes back to my earlier point about ground penetrating radar, as the only realistic way of eliminating or finding a french drain. French drains are often recommended as a sympathetic damp repair solution, and this is often recommended by conservation experts. But lets be realistic here, if a French drain is installed 1 meter away from a building 1 meter deep, what is this really expected to do? One thing for sure you will be guaranteed a damp wall with rising damp symptoms.
Land drains have been used since the Roman times to drain the land. It is also well documented that land drains have provided a solution to help with flooding of fields etc, and agricultural drainage using land drains was a solution. This helped to ensure the farmers could gain maximum yield from crops, this making well drained land more valuable.
What I have found interesting when trying to understand excess moisture within a building like rising damp is that it can often be complex to find the root cause. During my research one of the things that I found very interesting is that drainage of sub soil, and prevention of damp was specified prior to the introduction of a physical damp proof course. The earliest I could find it mentioned local to me in the Bye-laws of the Warminster Wiltshire Local Board wasin 1868. It is virtually impossible to find all the local byelaws from all my local towns, bearing in mind most of the ones im looking for are around 170 years old. I would have thought sub soil drainage was at least introduced in the Byelaws from 1850’s like other parts of the UK. As you can imagine I have found land drains previously just by luck when lowering ground levels to reduce damp issues. By finding the land drains, and the many issues with bodged up French drains, this was the reason for purchasing ground penetrating radar. It is really the only solution for potentially eliminating, or finding the defects that saturate the walls of buildings.
If you need to know the price of a ground penetrating radar survey you can ring the office on 01225 769215 or email firstname.lastname@example.org
This example from a damp survey and investigation, where the repairs were carried out by Complete Preservation. You can see where I take you through my thought process of the issues, along with why I can justify the repairs needed. Traditional lime based materials will promote evaporation, and help to control rising damp issues. Unfortunately it isn’t unusual for somebody to have had a go before. If you need sympathetic rising damp solutions to include lowering high ground levels, removal of modern materials, and replacement with lime render and lime plastering, lime pointing, and modern paint removal this is the service we can carry out. We can also carry out CCTV drain surveys, drain lining, drain patching and all associated building repairs.
There will always be conflicting advice with repairing a traditional building. Fortunately the agreed joint damp methodology by RICS, Historic England, PCA, SPAB will be published very shortly, and I can only hope this sort some of this out. The new joint draft methodology – Investigation of moisture and it’s effects in traditional buildings joint damp methodology is explained here https://www.completepreservation.co.u…
A very interesting enquiry has come in about an investigation of a flooded culvert in the grounds of a very old building.
Whilst part of the location of the culvert is known, knowbody knows where this actually starts or ends. This was built for a purpose, and it will be beneficial to work out where this actually leads to. One of the main reasons for this survey, is that this might be related to the persistent rising damp issues within the listed building. As most people are aware drainage defects are a common cause of damp, along with blocked French drains, land drains and also blocked/restricted culverts
Having come recommended from where I recently discovered a culvert, the question was asked is this something I could do for them. I love an interesting survey, and this is something I’m sure I could get some kit up together for. A battery boat will have 3 sets of led lights, 2 x GoPro cameras, live front view camera, real time sonde, so location can be tracked from above ground, real time sonar, which will give depths of culvert along with a view of the bottom. Tests will be carried out next week, to see if any teething problems occur, and just need to set the date. Ground penetrating radar will be used initially to see what I can also find.
If you think you have hidden drainage, culverts, wells, basements that you want an investigation into please get in contact. Ground penetrating radar surveys should easily pick this stuff up email@example.com
Damp investigations and advice will massively vary with what a client will get. This is simply because some damp investigations will not be thorough enough, and will be non invasive / non intrusive. Also it isn’t unusual to get different opinions on how to fix the issues. This is where it can get difficult especially if no data has been produced by taking plaster samples, as per BRE DIGEST 245 https://www.completepreservation.co.uk/what-is-bre-digest-245/ This then results on diagnosis confirmed just by an opinion, not by data…..If you need a damp survey that is based on opening up, data by sampling, to include drains surveys etc, please contact the office on firstname.lastname@example.org
Whilst this is still the draft methodology the new methodology will be published very shortly.
Do you know the questions you need to ask prior to instructing a damp specialist surveyor? This video explains and tells you the very basics that includes the facts from the British Standards
Bridging of the damp proof course, or bridging of the dpc, is such a common cause of rising damp to internal walls, and also external walls. BS 6576, and BRE DIGEST 245 is the standards that all damp surveyors should be following. As per the video you need to ask your damp surveyor some vital questions. If you don’t ask these questions you might fall into the trap, and perhaps your root cause of rising damp will not be diagnosed correctly, that could result in expensive treatment and repairs. By getting the correct survey initially, it will add value long term.
1. First of all you need to make sure your damp surveyor is suitably experienced, and qualified.
2. You must ask for an invasive / intrusive survey if it’s anything to do with damp at the base of the wall, and possibly bridging of the dpc, like rising damp. Non invasive surveys will simply not be good enough.
3. An averagely competent surveyor will follow the guidance in BS 6576, as per what I have spoke about in the video.
4. They will also need to follow the methodology in BRE DIGEST 245. This is basically the only quantitative methodology to confirm rising damp, by using a carbide meter / speedy meter or better still gravimetrics.
5. Make sure all of the below are eliminated as a potential cause by your damp surveyor, as per guidance in BS 6576.
2. Lateral penetration associated with ground and floor level
3. Leaks from roofs gutters, and downpipes
4. Faulty drains
5. Internal plumbing leaks
6. Water penetration through external walls
7. Water penetration around windows and doors
8. Mortar droppings in the cavity
9. History of flooding
I do find that if a physical damp proof course is present and there is damp on internal walls, there is a high possibility there could be drain issues, or a possible leak.
A rising damp survey is all about the damp investigation. The new RICS joint damp assessment methodology, which is to be published shortly goes through the stuff I go through in this, and my other videos about eliminating root cause. This video will show you how I go about some of my damp investigations, and some of the defects I find. At the end of the video I give a little bit of advice to any homeowners, on how you can potentially start your own damp investigation. Right at the end are the graphs of the gravimetric moisture profile following the guidance in BRE DIGEST 245. I explain about these in the video, and why this is important when moving forward with repairs. Any questions drop them in the comments below and i’ll do my best to answer when I get 5 mins. Have you seen the recent joint damp assessment surveying methodology by Historic England, RICS, PCA, SPAB? Click on the link below for more details https://www.completepreservation.co.uk/rics/
Ground penetrating radar can really help identify, or even eliminate the true cause of rising damp issues. This short video will show you the drainage and culverts that it identified, as part of the GPR survey.
If you wanted to bring your traditional or historic building back into moisture balance using traditional breathable materials, then perhaps gpr should be used to make sure a long term solution is proposed.
Ground penetrating radar survey, is also called a gpr survey.
What can ground penetrating radar detect?
Can ground penetrating radar detect an old covered over basement / cellar?
Can ground penetrating radar detect leaks in mains water pipes?
Can ground penetrating radar detect a covered well?
Ground penetrating radar has the potential to find all of the above, subject to the limitations of the GPR equipment being used, and the ground conditions at the time of survey.
I have really only purchased this equipment to really help with solving complex rising damp issues. This equipment will give me the opportunity to go further with the investigation, and identify any other potential causes. We all know rising damp issues are caused by excess moisture, and this moisture could be coming from the ground via defective and damaged leaking wells, poorly installed French drains, blocked up old culverts, blocked up old land drains, and general drain issues.
In 1868 the bye-law of the Wiltshire Warminster local board, was the first one to deal with damp, before a physical damp proof course became part of the bye-laws (see below).
Drainage of sub soil and prevention of damp. Warminster Byelaw 1868
The house drainage shall be so constructed either with additional earthenware pipe drains or otherwise, as to drain the subsoil of the premises, whenever the dampness of the site appears to the Board to render this necessary; and all rainwater shall be so drained or conveyed from the roofs buildings as to prevent it’s dripping onto the ground and causing dampness in the walls.
What I did notice though, in the drainage section all drain pipes had to be laid with watertight joints, and beneath houses they shall be imbedded in and surrounded with well puddled clay… no mention of this with the subsoil drainage though.
As you can imagine these land drains would be possibly blocked up by now, and might even be damaged, causing ponding water to that area, and possibly subsequent damp issues within the property. The ones I have found previously was just simply by luck!
I’ve done some videos that will certainly make you think how valuable this is, in regards to damp surveys…..look at the well in the image that was covered over, knowbody knew it was there.
Extract below about land drains, and drainage from an old book in regards to damp issues. Ive noted on all references to the hidden land drains, that there is always a slightly different specification to install… but they all talk about them blocking up, and potentially causing problems.
The greatest difficulty with which an architect has to contend with in the ground-works of a building is that of the ground water in low-lying lands. Springs on hill-sides are easily dealt with, but the water which percolates through mud and gravel only a few feet below the surface of the ground, and rises and falls perhaps with rise and fall of a neighbouring river or ditch, furnishes a more difficult problem. Nor is a site like this confined to plains; it may be found on the banks of rivers, even in deep narrow valleys.
A permanently high level of ground level of ground water is dangerous of health, but fluctuating ground water is much worse. It is one advantage of subsoil drainage that it tends to prevent extreme rise of the water, and so lessen the degree of fluctuation.
The level of ground water, it may be added, is always raised by capillarity. The amount of rise has been estimated at about 1 foot in sands, and 4 or 5 feet in clay and compact marl. The rise will be lessened in many soils by properly opening them and draining them.
In many cases, it is a mere farce to talk of draining subsoil to a depth of 6, 8 10, or 12 feet; not until the ocean has been drained, can the level of ground water in many parts of these islands be permanently lowered. Where the sea has to be kept out by dikes and sluice-gates, it is of little use talking about subsoil drainage. So difficult is to to render dwellings on such low lying sites habitable, that by the London Borough Act 1894, the London County of dwelling house upon them. In many elevated places, however, there are even damp and boggy, patches of ground, and these can easily be drained, because there is an outfall for the drain into the valleys below.
The essential fact to note is that subsoil drainage can only be carried out if there is a lower soil to drain to. In the absence of this the site must be raised if necessary.
Not all ground requires under drains : many rocky, sandy, and gravelly sites are sufficiently dry already. But every site must be judged by itself, as the nature of the ground varies greatly even in a short distance. It is better, however, to drain too much than too little. The drainage of clay soils renders them drier, and, by reducing the evaporation, warmer. Sand and gravelly soils are naturally drier and warmer than clay; on account of their porosity of water rapidly sinks through them, and they contain a considerable volume of air. In these the fluctuation of ground water and consequent exhalation of more or less impure ground air are more to be feared than dampness.
Sub-soil drains are sometimes merely trenches cut to the necessary depth, and filled to the height od=f 2 or 3 feet with broken stone or chalk lumps. The ground water finds its way along these “rubble drains” (for so they are called) to the appointed outlet. Sometimes a small square drain is formed at the bottom of the trench of stones, or with tile bottom and brick sides and top. Pipes, however, permit the water to flow off more rapidly ad are less liable to choke than stones drains. They may be either round or D –shaped. And should not be less than 3 inches in diameter. Unsocketed agricultural drain pipes are often used, but there is some difficulty in keeping the ends of the pipes together, both horizontally and vertically. To obviate this , half collars 3 or 4 inches long are sometimes placed under the joints, or pipes with a socket on the lower half only are used. Ordinary socketed drain pipes are also used, but with the joints left without cement or clay. The last two methods are the best. Whatever kind of pipe is used, the trench above should be filled with broken stone or screened gravel to the height of 1 or 2 feet.
In very wet and loose sandy soils, drains may carry away, little by little, considerable volumes of sand, and so endanger the ground and structures above. In extreme cases of this kind, sub-soil drains will be best omitted, and the money thus saved expended on a concrete bed over the site covered with a layer of asphalt. The depth of the sub soil drains should be as great as possible, but considerations of outfall and expense will frequently prevent the depth being more tha 2 or 3 feet below the lowest floor. Where the drains are shallow, they should be close together than is necessary when they are deep.
The distance apart of sub-soil drains must depend on upon their depth, the quantity of water and the nature of the ground. A common rule for the distance apart is two or three time s the depth. The stiffer the ground, the close they must be . In stiff clay they should be laid every3 or 4 yards, in loamy clay every 5 or 6 yards, while in sand and gravel they may be omitted altogether, or at the most a single drain may be laid around the outside of the building. In the other cases, however, it will usually be necessary to lay branch drains across the site in addition to the important drain encircling it.
Any walls crossing over a rubble drain should have a rough arch formed above the footings, so as to carry the main weight clear of the disturbed ground.
The outlet for ground water must be arranged according to circumstances. In many towns now, special “sewers” for surface water and ground water are provided, emptying into the nearest stream at various convenient points. In the country the sub-soil drains may be carried to the nearest stream or ditch, or, if there is sufficient fall, brought to the surface of the ground at some distance from the house. Where, however, they must be connected with the sewage conduits, they must be trapped from the house drain as well as from the public sewer.
The best method is to build an inspection chamber by the side of one of the inspection chambers on the sewage drain, and to build the trap into the wall between the two, but well above the sewage drain, so that sewage cannot pass into the trap. There is one obvious dis-advantage in the connection of the sub-soil drains to the sewerage-drains, and that is that in dry weather the water in the trap my evaporate, and more or less foul air from the sewage –drains may then pass along the subsoil drains, and find its way into the house. The risk is reduced by connecting some of the rain-water to the inspection chamber in which the trap is placed, but at the best the connection of the sub-soil drains to the sewage cannot be recommended. On flat low lying sites, it is better to raise the house or terrace, and to drain the ground to as great a depth as possible by means of open ditches, into the water-drains from the house can be laid to discharge.
If you have a damp issue I have the necessary equipment, along with the experience to find out what is the root cause, by eliminating any potential causes.
How much is a ground penetrating radar survey?
Survey costs can vary depending on what is needed. Mine is mainly used to help solve damp issues, where excess water can be causing rising damp issues or flooding within a property. This is normally used as add on, as part of a damp investigation.
If you have any queries, and need have a problem, you can email me email@example.com
Soakaways that have been installed many years ago are likely to be an issue. This is based on experience in finding the root cause of rising damp issues, and suspended timber floor decay. Really a soakaway needs flood testing, along with a CCTV drain camera survey. Once this is carried out, only then can I offer guidance on any repairs. It isn’t unusual to be offered a free damp survey, but it is highly unlikely you will get the best advice where all potential causes have been eliminated as the root cause. Please note I don’t offer a free damp survey. If you need professional advice in regards to your damp issue please email firstname.lastname@example.org