Lectros Osmotic Damp Proofing System Problem

[Poisonata]

I’m in the process of installing a Lectros Osmotic Damp Proofing System in my Victorian property. After taking advice from two people who install these all the time it seemed extremely easy for someone adept at DIY. Problem is the Power Unit Green LED does not illuminate when the system is switched on indicating the system is operating properly. A friend tested the Power Unit on his exact same system and it worked just fine. The socked it is plugged into works correctly and the contacts between the unit and the earth wire/titanium wire have been checked also.

I concluded that it could only be one of two things, either the earth wire (this runs out of the house and connects to an earth rod embedded >6 foot away from the property extending 4+ feet into the ground) was not correctly attached to the rod or something is amiss with the titanium wire.

The earth rod I installed myself, there really wasn’t a lot you could do wrong here and I took great care to ensure the connection between the earth wire and rod was sound.

Here is where I think I’m possibly missing a trick. The titanium wire I have only partially finished embedding in the wall so I have tested the power unit by uncoiling a 15 meter roll of titanium wire through the length of the house (making sure it sits only on non conducting material i.e. carpet).

I can only conclude either the unit isn’t earthed properly and there is some break in the earth wire or uncoiling a length of 15 meter titanium wire which is not embedded in the wall, merely laying on carpet/lino is unsatisfactory for the operation of the unit.

My first thoughts are it must be the earth wire/rod as my understanding of the power unit is that unless it is earthed correctly it will not work. I do not see how as only one end of the titanium wire is connected to the power unit and it sends a ‘pulse’ down the wire how it would matter what length of titanium wire was attached for it’s operation. The only thing I can conclude is that maybe the fact the ‘test titanium wire’ is not embedded in the wall has a bearing on the operation of the unit.

What I would like to know is, in the full knowledge that the power unit works correctly is it more likely to be the fact there is an issue with the earth or is it the fact that the titanium wire I’m using to test the unit is not currently embedded in the wall. I’m thinking of going back to my chap who tested the power unit for me just to connect it to his earth rod and not the titanium wire loop to see if the power unit operates (i.e. the green light comes on) then I would know where the issue stems from.

If anyone has any knowledge of these systems and can see where I’m going wrong I’d be very grateful for a response. Also if you require additional information/pictures please say. I’m finding this whole issue frustrating to the extreme. Many thanks in advance for any responses.

 

[PrenticeBoyofDerry]

Can't say I have ever used or have any experience in this product.
But I am assuming it works using the a chemical(electrolytic) reaction to create the circuit between the anode that should be inserted into wall and the rod outside.
So I would at least have the anodes within the wall cavity as per instructions, so a circuit can be made.

 

[Poisonata]

Amazing what a fresh pair of eyes can do. After I made this post I contacted my pal with the same system who said the only thing he could see was inconsistent was the fact the titanium test wire I had used was not embedded in the wall. He suggested connecting the length of titanium test wire to the wire I had already embedded in the wall. And guess what, it worked.

So many thanks to PrenticeBoyOfDerry as you were spot on. Seems ironic in the short time between my initial post and resolving the issue you were kind enough to post the correct solution. Thank You button clicked.

 

[PrenticeBoyofDerry]

No worries, glad to be assistance and pleased to hear the equipment is now functioning as it should be.

 

[Peet]

It's nice to hear talk of an electro osmotic damp proof system on the forum. The technique IMO is a much preferable alternative to injection systems and often easier to install. If installed correctly it's very reliable. Sometimes in delicate and or historical buildings you have no choice. Installation is well within the range of the competent DIYer.
They usually fail because they've been disturbed, somebody drilling through the wire is a common one. But then many builders don't know what it is and repair the break with copper wire which fails after a while.

Unfortunately there seems to be some mystery surrounding electro osmotic damp systems, when they're actually quite straight forward. Hopefully this will dispel some of it.

A DC power supply, in Lectros' case unsmoothed, forms a voltage field in the wall with reference to it's dedicated earth rod. This destroys the water's ability to climb the porous wall by capillary action. Apparently the reverse effect is seen in damp walls, producing a potential difference up them.

The Lectros power supply is a simple centre tapped transformer, rectified through a couple of diodes and then through a current steering circuit to protect the LED from excess loop current. The LED will indicate a wide range of loop current. At the low end about 40uA will produce a barely discernible glow. It's fully lit at about 20mA. Excess current is bypassed around it and ultimately limited by resistors, so the power supply operation can be crudely checked out by shorting its two output wires together to make the LED light. After all, a power supply designed to be connected to bare wires in a wall could be reasonably be expected to endure this.

The flowrate of the water is directly proportional to the current flowing in the loop formed by the power supply, the anode/s in the wall and the wall/ground. So yes, the system doesn't work if the power supply is connected to a piece of wire with no current path to the wall and back to the earth rod.
Confusion often comes here by the fact that the system uses the titanium wire as one electrode in a circuit and not as a continuous loop around which to pass current. Although you can return the end of the titanium wire to the same power supply power supply terminal if you wish, thus forming a loop.

The voltage out is in the region of 17v (yes, on a supply marked 5v!) unloaded, falling with load. The absence of electrolytic capacitors in the power supply should aid its longevity.

Maybe of little use to you now but hopefully help to others in the future - some recommendations for installation:

Crimping the titanium collars.
I've seen people use various methods of crimping the titanium rings. So-called professional installers hitting them with a hammer, and various standard electrical crimp tools being used on them. Look carefully at the Lectros installation sheet for the desired 'crescent' crimp shape. Standard yellow/red/blue crimp electrical tools will not crimp the titanium collars properly. Neither will hitting them with a hammer. BICC and Cembre both make crimp tools very similar to the one in the Lectros information and these work very well. Make sure the wires and collars are clean and parallel so they sit properly in the crimped collar. Also the 50mm spacing between the 2 collars to join two wires works well and aids the wire's integrity.

The earth rod.
The system needs its own rod. The Osmotic system should have no direct connection to the electrical system. This is VERY important. Put the rod in as per the instructions and below the lowest anode in the wall. If it's a problem achieving enough distance from the closest anode then use a longer rod, tape up the top part of it, making the active part of the rod deeper in the ground. Furse do 5/8" rods which can be joined with their equivalent of studding connectors and they have a better cable clamp too. Also the copper on these rods is better bonded to the steel rod than the 3/8" ones. They'll last longer.
A lot of electrical wholesalers only stock the single 3/8" rods. These cannot be stacked to achieve greater depth.

Anode burial.
You can make a cement putter-inner yourself from a squeezy pint wood glue bottle with some plastic pipe on the end, or the larger brown sauce bottles. There's usually some nice big clear ones on ebay. You want a pipe of around 10mm dia. Make sure the anodes are properly buried, I've seen many not properly buried and showing their yellow heat shrink. Use a bit of Armaflex or other soft closed cell foam to push up against the hole with a brick, to stop the cement slurry from coming out while it sets. Make sure the anode hole is filled from the bottom upwards and there's no air bubbles. The slurry should be just that, quite watery. I form the anodes by hand to avoid damaging the platinum coating on them, I'm not sure if it makes any difference to their reliability.

Hope that helps.

 

[ban-all-sheds]

Furse do 5/8" rods which can be joined with their equivalent of studding connectors.

They also do thermite welding kits, which have got to be more fun to use...

 

[Peet]

Oh definitely Ban. Had great fun with thermite orientated stuff as a kid. Not sure if it was more fun getting them going, or the fruitless attempts at putting them out. These days people ask too many questions.

 

[Poisonata]

Extremely interesting post Peet and essentially the final pice of the puzzle. Although my knowledge was sufficient to install the system, my true understanding of its exact operation was lacking. Now I see how the complete circuit is made and why a separate earth rod is required for its use. The professional installer told me very specifically that the system required its own earth rod. When I asked him why an earth couldn't simply be bonded into the consumer box earthing block outside he said 'How the bloody hell should I know, it just can't, ok '. Quality advice here !
I can only imagine that over time the circuit will cause the earth rod to degrade albeit at a phenomenally slow rate, essentially nothing of me to worry about in my lifetime.
The correct crimping device is huge, 30 inches long and you need a decent amount of slack on both ends of the wire to crimp the titanium ring onto both wires. A 'bull nose' cone of the crimpers forces the ring into a crescent shape encapsulating both wires neatly.
The professional installer told me of a job he inspected done by a now retired 'professional'. He had essentially failed the fill the drilled holes with mortar after the anodes were inserted and had just pointed up the titanium wire. The system was ineffective and was eventually replaced. So word to the wise, drill your holes at a slight downward angle and use a small watering can to tip in cement slurry which will ensure a solid anode connection.
Reason I investigated and essentially installed this system was after a professional damp course company inspected my property and suggested the old blue brick layer was providing inadequate damp penetration protection. Very true, I checked all the findings myself with a protometer. He suggested the only 'sure' method was chemical injection Dryzone method which all in (including labour, making good damaged internal decor etc) costing a tidy £7000. What he failed to mention was the fact that in my opinion a far superior and less messy electric damp course was also viable. If his quote has not been significantly more than I had anticipated I would have gone ahead and been oblivious that any other satisfactory methods of achieving a dry wall existed. Cost of 3 rolls of titanium wire (75m), titanium rings, power unit, earth wire and rod, shade over £500. I did the installation myself (which is not difficult at all) and saved £6500.
Feel free to message me if you are installing such a system. I don't claim to be an expert but I now have experience of installing a working system and have access to two professional installers.

 

[RF Lighting]

What an interesting thread! You learn something new every day on these here forums!

 

[Chri5]

Maybe the mods should wiki both your notes, better still a pictorial.

Even if nowt happens, thanks for the detail. Are such systems approved and tested via the BRE, is there record of longevity, peformance and design limitations?

 

[adamr7747]

Unfortunately there seems to be some mystery surrounding electro osmotic damp systems.

Yes, I've read various things about them being snake-oil. I've no idea if that's true or not but this doesn't fill me with confidence:

A voltage field ... destroys the water's ability to climb the porous wall by capillary action.

Really? Do you have any more information on the science of this?

I'm happy to keep an open mind though - I'd be very interested to hear back from Poisonata if the system works in the end (assuming he's not taking any other remedial action)!

Adam

 

[gregers]

this isnt a new idea,i was told when i was in the preservation industry that rentokil used to do this method a lot in there early days,but through lack of knowledge or bad workmanship they almost went bust on gaurentee claims??????????
how true this is i have no idea,like all industries there are always chinese wispers.
i have been invovled in just 1 installation of this method,i found it quite interesting,but had always wondered how when the rods you make are approx 6-8 inches apart and running on a fairly low currant.

mind you i DID have the biggest high ive ever had on that job,we used to get our (gripfil)adhesive from the likes of sovereign chemicals iirc it was a fairly new product out,and me being the numpty i was back then spent the day inside using this stuff installing all/any joinery that needed to be put back.yep and didnt open any of the windows at all.BOY DID I HAVE A HEADACHE.
i suppose another reason why you shouldnt use plugs and screws installing the skirtings is maybe the screws will make it go a bit haywire?

 

[ban-all-sheds]

fruitless attempts at putting them out..

No access to large quantities of liquid nitrogen, then....

I hope you never tried water.

 

[Peet]

As regards the science of it.....
The wiki for it has some info on it http://en.wikipedia.org/wiki/Electro-osmosis

So now, armed with that lot, you no longer need to wait for a full moon to draw the juices up the plants to harvest the fruit. Get your friendly neighbour hood electrician to install an outdoor socket and an old line output transformer off a colour tele to a bit of mesh suspended above the tomatoes. And you wondered why Rhubarb grew faster during thunderstorms. Just remember to install a seperate earth rod for the veggy patch.

and www.lectros.com also has some good stuff http://www.lectros.com/lectros_datasheets.asp The review of the system PDF file in particular for the science of it.

The professional installer told me very specifically that the system required its own earth rod. When I asked him why an earth couldn't simply be bonded into the consumer box earthing block outside he said 'How the bloody hell should I know, it just can't, ok '. Quality advice here !

Nice one! That gave me a right good laugh.

In terms of does it work? It most definitely does. A friend has lived in a house now for maybe 10 years and we wondered what it was at first. The surveyor for the mortgage firm was clueless about it, insisting on all kinds of things be done, until he was put right by the EO specialist and backed up with a Calcium Carbide meter. Once it was on the radar I investigated it and found quite an interesting system. It'll do all kinds of walls, cavity or not. Perhaps the only viable system for doing old stone walls that have an adhoc cavity that's full of debris. Since then I've installed a couple of systems and been very pleased with them. It's also the only DPC system that aids the wall drying out as it doesn't put a physical barrier into the wall.

The independent earth rod is important as I'd guess if the system was joined to mains earth you could start to see some interesting destructive effects. Like migration of metals perhaps? You can use mains earth to check you have some form of a connection to the earth rod by metering between mains earth and the rod, if physical inspection isn't easy.

The correct crimping device is huge, 30 inches long and you need a decent amount of slack on both ends of the wire to crimp the titanium ring onto both wires.

Thats the one! Yep getting it into tight corners can be tricky.

He suggested the only 'sure' method was chemical injection Dryzone method which all in (including labour, making good damaged internal decor etc) costing a tidy £7000. What he failed to mention was the fact that in my opinion a far superior and less messy electric damp course was also viable.

I suppose chemical injection must work but I've seen a lot of failed ones. I can't subscribed to its methods and that it will offer an even impregnation of the wall. And in Accrington brick, then how does that work? I doubt the injected fluid will get far. I suppose you could do the seams? I don't know, never used it. And what if it fails? Do you re-inject, but now into a wall which has had its pores pumped full of stuff?
In contrast the EO system can be repaired and if the electrodes are too widely spaced you can break into the loop, connect another one in and off you go again.

If his quote has not been significantly more than I had anticipated I would have gone ahead and been oblivious that any other satisfactory methods of achieving a dry wall existed.

I bet that has happened countless times. I've no doubt there's first class damp specialists out there, but finding them can be tricky, especially when there seems to be an abundance of dodgy ones about who condemn a property damp wise and put in a large quote to fix it.
I remember a guy rolling up in his flash car, in a suit, with a clipboard, to a house I was wanting to buy. To do one of those quotes the mortgage firm wants to see as the surveyor has flagged damp on the report. I knew exactly what was wrong with the place but was interested to see what he reckoned. I watched him prod round with his Protometer, tut and puff, scribble stuff down, and then tell me it needed about £1200 of work doing as the walls were shot. Ironically somebody similar to him had knackered the place in in the first place. 110 year old house. Originally no effective dpc. Somebody had very nicely dug out the walls and put in a membrane one. Top job. Then somebody had rendered over it internally. Crowd go 'oooooo'. Then it got damp. Then somebody called out another damp man, who advised injecting it. They did - by drilling holes through the original membrane which was until then intact. Problem 'fixed'. Cough.

If this thread prevents just one of those cowboys pulling the wool over people's eyes I'll be delighted.

The only thing I did wonder about with the system was what grade of transformer was in the wall wart PSU that Lectros use? It's not marked. To my mind it would need to be isolation grade. There's no discrete fuse in the PSU and the transformer primary is wired straight to the prongs of the plug case. It is thermally fused internally though apparently.

What an interesting thread! You learn something new every day on these here forums!

Everyday is a school day RF . Your posts have often been very informative to me.

Protometer meters are okay for prodding about with but they're no substitute for the best test equipment, that being your eyes, hands and brain. I've never actually noted if the live EO system effects the protometer readings. I'll try that one out sometime soon.

 

[Peet]

fruitless attempts at putting them out..

No access to large quantities of liquid nitrogen, then....

I hope you never tried water.

Water? That was the whole reason for trying it
Well no, it was the 2nd. The first was to see what we could cut our way through. You know how it as kids. Or was that just me? But the water was interesting. Seeing if we could get it to crack. Often the results were too catastrophic to tell what we'd done. And it was easier to setup than the spin dryer and charcoal blocks. People mention water hammer, that was a different league.

Sadly no liquid Nitrogen, as kids we were yet to gain a BOC account.

Ban, you'll be pleased to know that the childhood apprenticeship in physics & chemistry has been put to good positive use over the years. Including showing a fireman how to start a chip pan fire on a fire training course. Although our methods of putting it out varied drastically.