Electro Osmosis is scientific theory that is being pushed by various manufacturers as a 'cure' for rising damp. Strange that - a cure, for something that barely exists, if at all.. The 'technology' has been investigated by various scientific organisations - including one that I used to work for in Australia. I think its fair to say that if you pay someone a lot of money to write a report on something for you, there's a good chance they are going to paint a fairly glowing picture of whatever it is, if you pay them enough dosh.... I have seen very little independent research that supports the idea, and if the BRE don't like it, it will take a lot to shift scientific opinion in the other direction. I've seen the so called 'scientific research reports' and there are such glaring holes in the logic you could drive a double decker bus through them. If you are thinking of buying one, do some literature research - you'll find the scarcity of research by accredited universities or completely independent scientific institutions rather deafening.
I have personally inspected over a dozen installations of these things in the last couple of years during the course of damp surveys - most of which were commissioned on the back of free surveys by 'damp proofing surveyors' which recommended one or more snake oil treatments. Luckily my clients realised that they were being sold a lemon, and sought independent advice. None of the electro osmotic systems seen in the surveys worked. Examples of names - Schrijver, Hydrotec Wallguard, Lectros - All of them were in sopping wet houses with peeling plaster and wet walls. All of the properties were easily diagnosed as having specific problems that could be solved, and indeed have been, without resort to electrical trickery. In most cases the wire systems were still plugged in and live - and none of them had achieved anything. All have now been ripped out, and the actual damp problems diagnosed and solved. Most of the big damp proofing companies try to flog them - Rentokil keep trying, as do Peter Cox.
Because of the thoroughly nasty reaction of the damp industry to anyone who dares challenge any of their snake oil remedies (which are of course making them a lot of money), we are asking anyone who knows of, has seen, or experienced one of these systems to contact us with a case history. I'd like to investigate ANY installations to see how effective or otherwise they are, and to thoroughly investigate the circumstances surrounding the installation. Are there other causes of the dampness than the so called 'rising damp' that they claim it 'cures' - can we diagnose these and sort the problem. Did the 'damp salesman' attempt to properly diagnose causes before selling a gadget? How has the success or otherwise of the gadget been monitored? If you'd like to contribute, please use the feedback form on this page..
From now on, I will be carefully recording ALL of the installations I see, and presenting a detailed analysis of what I see, and how effective - or not - it has been. I want to present unbiased analysis of this technology - hard, given that I've never seen any installation that worked, and a lot that didnt...
The following text is from a publication in this country by the Building Research Establishment which I think is fairly self explanatory: (My thanks to the Building Research Establishment for this...)
"There are two types: active and passive; neither has been approved by a recognised laboratory. By far the greater number of systems are of the passive kind, where there is no external source of electricity. They have always been something of a controversial issue. On theoretical grounds, it remains a mystery as to how they can work; their effectiveness has not been demonstrated in the laboratory and field evidence is disappointing.
Active electro-osmotic systems use an external source of electricity. BRE has no evidence to suggest that the two types behave differently in practice, though some of the active systems may be rather susceptible to the effects of mechanical damage and electrochemical corrosion...
...The claim for passive types is that a damp wall contains an electrical potential and the earthing of this potential causes the dampness to fall. It is true that the existence of electrical potentials in a damp wall can be demonstrated. However, where such potentials are caused by the movement of moisture and salts in the first place, earthing the potentials might be expected to increase rather than reduce the upward flow of moisture and salts.
The installations inspected by BRE were coupled with a replastering system which provided a good barrier to moisture; it is suspected that claimed successes for the system relied heavily on the render and plaster system. As far as is known the passive system is no longer available, though many thousands of installations still exist. Active systems do attempt to make use of true electro-osmosis: the movement of moisture through finely pored materials under the influence of an electrical field. Site experience is not encouraging and, again, the systems rely on the assistance of plaster to contain moisture.
Of the complaints about electro-osmotic damp-proofing that BRE has investigated, some have involved condensation problems that the installation could not be expected to cure; in others there appeared to be at least partial failure of the system, suggesting that electro-osmotic systems are not effective in preventing rising damp in walls in all conditions.
The process supposedly uses a small electrical charge which is introduced to brick or stone walls via positively charged wires - called anodes. They are commonly sold as being platinum coated, or solid titanium - a very expensive way of buying a roll of useless wire. Manufacturers and chemical salesmen claim that the wire repels water and somehow chases it out of the wall and into the ground (you can hear the sound of hysterical laughter at this point... ). Thousands of these systems were sold in the 1970's and 1980's to unsuspecting householders. We frequently encounter them during building surveys when we are called in to investigate 'damp' houses which are suffering terrible problems - invariably there will be one of these systems somewhere - which of course never worked.
Rentokil were one of the worst offenders - selling a system that had a copper band which went right round the house - they cut huge holes in brickwork, and covered the thing with cement. There was always a box somewhere with Rentokil on it. The thing was a complete con and a failure.
If anyone tries to sell you a kit - which usually includes a power source, fancy control box, reels of wire, and goop to stick the wire to the wall, I suggest you seek the advice of Trading Standards, and do some very detailed homework. There are many references to these things on building forums - not one of the references I have seen are in any way supportive of the 'technology' - do your research, ask the forums, and if you really are convinced - make my day and buy one - but please let me know how your house magically dries out afterwards - I'd be delighted if it did happen, but I'll not hold my breath....
