Electro osmosis damp proofing - does it work?

my3cents

I would have thought some added ventilation when the window is cut in would also help. Only problem is you need to have a solution that your tenants can't mess up. Hardly unknown for staff to block up vents because they think that will make the place warmer only to create problems with condensation.

As I keep saying you need to get it dried out so you can see if the problem can be solved with heat and ventilation. Best option I can think of is to increase ventilation and put in a dehumidifier in one corner asap and keep checking to see if it makes any improvement.

One little test you can do for damp with no tools is to stick a sheet of plastic over an area you think is damp (also a test for the floor) then the following day take it off. If its really damp you will have water on the back of the plastic and even on the wall. If its bone dry what you are seeing on the wall isn't damp and only salt deposits or mold.

Also get yourself a cheap humidity meter (I got one from Amazon for my son for checking the humidity for hatching eggs £20 on Amazon worked great) and check the humidity over a period of time. If the walls are damp then humidity near them will be well over 50%. You could also get someone to do a proper carbide damp test (as shown in the videos). It may well be that the walls really are damp but if the results just prove the problem is condensation and lack of ventilation you can breath a big sigh of relief and know that you don't need to worry about damp proofing.

Which obviously raised the question how do you know its damp, can you feel it on the wall or is the wall moldy or has salt deposits. Mold more often than not indicates condensation rather than damp coming in through walls. A cold wall will also often feel damp.

v638sg7k1a92bx

my3cents wrote: »

I would have thought some added ventilation when the window is cut in would also help. Only problem is you need to have a solution that your tenants can't mess up. Hardly unknown for staff to block up vents because they think that will make the place warmer only to create problems with condensation.

As I keep saying you need to get it dried out so you can see if the problem can be solved with heat and ventilation. Best option I can think of is to increase ventilation and put in a dehumidifier in one corner asap and keep checking to see if it makes any improvement.

One little test you can do for damp with no tools is to stick a sheet of plastic over an area you think is damp (also a test for the floor) then the following day take it off. If its really damp you will have water on the back of the plastic and even on the wall. If its bone dry what you are seeing on the wall isn't damp and only salt deposits or mold.

Also get yourself a cheap humidity meter (I got one from Amazon for my son for checking the humidity for hatching eggs £20 on Amazon worked great) and check the humidity over a period of time. If the walls are damp then humidity near them will be well over 50%. You could also get someone to do a proper carbide damp test (as shown in the videos). It may well be that the walls really are damp but if the results just prove the problem is condensation and lack of ventilation you can breath a big sigh of relief and know that you don't need to worry about damp proofing.

Which obviously raised the question how do you know its damp, can you feel it on the wall or is the wall moldy or has salt deposits. Mold more often than not indicates condensation rather than damp coming in through walls. A cold wall will also often feel damp.

The walls feel really damp, sticky and crumble to the touch.
I forgot I had taken some pictures earlier, here they are https://imgur.com/a/cgkaAJj

In terms a dehumidifier, would I need to get an industrial unit down there or would domestic suffice?

Stoner

A quick point.

There appears to be a mishmash of blocks in use here. Some types of stone and blocks can be a conduit for letting water in.

I would definitely consider painting on SBR and the same for the tanking plaster, you can paint that on too.

You clean the wall, tank it then SBR clear coat.

SBR and possibly stick on plaster board with a vapour proof back with foam.

Do not drill the walls for anything after that. Stick on plasterboard, surface electrical services and plumbing coming from the ceiling down, have it at high level.

Of course follow the other advice to see if you can find a source for the water and stop it

But what I've mentioned will help I think if you are after a budget attempt.

You can mix SBR into leveling compound for the floor too.

Have a look at my old thread on it, all be it I'd a simpler problem and I'm no expert, I got good advice from the suppliers. As hinted at above you'll get all sorts of advice on this many will be expensive, but this suggestion is an attempt to tank the space and to put a thin layer of plastic like material on over it, mostly it can be achieved with brushes.

I'd ask the lads in the suppliers too. They may have an excellent chemical solution.


Let us know what they say if you do call them.

Calahonda52

if the substrate is not good stable enough, then the SBR may just peel off in time, especially if there is any hydrostatic head.
Having said that, the pictures don't look too bad.
Is the paint oil based?
Is it sticking on well or flakey?

my3cents

At this stage I wouldn't rush into tanking because this is the one chance you have to find out what the real problem is. Tanking may be the answer but it will also at least temporarily cover over the problem. That really doesn't look that bad and that walls look in much better condition than I expected.

It almost looks to me like that tap in the second picture is leaking and adding to the problem but that also looks like it might be an old oil pipe for heating?

There also looks to be drain in the third picture, thats interesting and needs investigating as to why its there. For example it could be a proper foul drain and part of the damp issue or it could be a drain to allow the cellar to drain after a flood - meaning its know to flood.

The pics are a little low down to see any sign of ventilation but ventilation would still be my first response because until thats done you can't really make an informed decision.

Any dehumidifier is going to help, even if it just shows you that its pulling massive amounts of water out of the air. The problem may just be that a dehumidifier needs checking daily and I don't know you are in a position to do that. If that drain exists and isn't part of the problem you could set up a dehumidifier to use it as a water outlet.

At this stage if you don't know the history of that cellar and given the neighboring ones are filled in I'd want to find out if there is any history of that cellar flooding when there is a lot of rain. I had a cellar like that in the UK, it only flooded every couple of years after prolonged rain but a couple of foot of water isn't funny. If the cellar is in an area called something like Spring Field Road or Well Street take the hint. If it does flood its obviously a bit more than a tanking job to keep it out.

v638sg7k1a92bx

my3cents wrote: »

At this stage I wouldn't rush into tanking because this is the one chance you have to find out what the real problem is. Tanking may be the answer but it will also at least temporarily cover over the problem. That really doesn't look that bad and that walls look in much better condition than I expected.

It almost looks to me like that tap in the second picture is leaking and adding to the problem but that also looks like it might be an old oil pipe for heating?

There also looks to be drain in the third picture, thats interesting and needs investigating as to why its there. For example it could be a proper foul drain and part of the damp issue or it could be a drain to allow the cellar to drain after a flood - meaning its know to flood.

The pics are a little low down to see any sign of ventilation but ventilation would still be my first response because until thats done you can't really make an informed decision.

Any dehumidifier is going to help, even if it just shows you that its pulling massive amounts of water out of the air. The problem may just be that a dehumidifier needs checking daily and I don't know you are in a position to do that. If that drain exists and isn't part of the problem you could set up a dehumidifier to use it as a water outlet.

At this stage if you don't know the history of that cellar and given the neighboring ones are filled in I'd want to find out if there is any history of that cellar flooding when there is a lot of rain. I had a cellar like that in the UK, it only flooded every couple of years after prolonged rain but a couple of foot of water isn't funny. If the cellar is in an area called something like Spring Field Road or Well Street take the hint. If it does flood its obviously a bit more than a tanking job to keep it out.

Never floods and those drains are for waste water. The tap that you see there has no water supply, it’s been disconnected for donkeys years.

Going to get the dehumidifier down there and run it for a few hours and gauge the water extraction.

my3cents

Don't forget that you need a bit of heat for a dehumidifier to work efficiently. Another thing to check is the temperature down there at just above floor level, middle and just below ceiling. A decent difference between the floor and ceiling could (only could) be the reason for the damp on the walls lower down.

v638sg7k1a92bx

Calahonda52 wrote: »

if the substrate is not good stable enough, then the SBR may just peel off in time, especially if there is any hydrostatic head.
Having said that, the pictures don't look too bad.
Is the paint oil based?
Is it sticking on well or flakey?

The walls are sticky and crumbly to the touch. Does that indicate an like based paint?

v638sg7k1a92bx

my3cents wrote: »

Don't forget that you need a bit of heat for a dehumidifier to work efficiently. Another thing to check is the temperature down there at just above floor level, middle and just below ceiling. A decent difference between the floor and ceiling could (only could) be the reason for the damp on the walls lower down.

I haven’t noticed a significant difference in the temperature between the two levels.

my3cents

Baylor Angry Pumice wrote: »

I haven’t noticed a significant difference in the temperature between the two levels.

So possibly (very likely) condensation at the lower level.

Don't take anything I say as gospel, I'm just trying to get you to get a good idea of what the problem is so you can make an informed decision as to the best course of action.

my3cents

Baylor Angry Pumice wrote: »

The walls are sticky and crumbly to the touch. Does that indicate an like based paint?

Any idea how old the paint is? The older the better really if its still in that shape after years and years it really isn't bad at all. A really old paint could be lime bases, breathable and would be sticky and crumbly by now. The moisture in it could make the lime sticky.

v638sg7k1a92bx

my3cents wrote: »

Any idea how old the paint is? The older the better really if its still in that shape after years and years it really isn't bad at all. A really old paint could be lime bases, breathable and would be sticky and crumbly by now. The moisture in it could make the lime sticky.

The paint job is at least 15 years old. That’s when the previous tenant moved in and they haven’t touched the basement as it was just hoarded with junk for 15 years. Probably even longer.

my3cents

Baylor Angry Pumice wrote: »

The paint job is at least 15 years old. That’s when the previous tenant moved in and they haven’t touched the basement as it was just hoarded with junk for 15 years. Probably even longer.

The age might have given away the type of paint. At 15 years even 25 its probably not an old lime based paint. Is it plasticky or just brittle if you get good size flake and try and break it?

But knowing the type of paint won't solve the problem. Its just that if that paint is over 15 years old an if its a modern paint then an awful lot of it is still on the wall if the problem is water pushing through from the outside.

From my limited knowledge (remember I'm not a qualified expert just a keyboard warrior) I think the main problem is condensation through lack of ventilation.

Personally I'd go for an older lime based or at least breathable paint on the walls (strip as much of the old paint off as possible) and heat and ventilation, others will disagree it really is personal preference but then lime based paints will rub off on your cloths so not really any good in an office.

Positive extraction of air (as in the video) provided fresh air can get it may also be useful in lieu of a more expensive heat exchange system.

I quite sure most of the damp specialists you could get in will tell you its damp from the outside and will recommend some sort of damp proofing. You just need to decide for yourself if that really is the correct answer and at this stage you should be armed with enough information not to be conned into something that is just going to be unnecessary expense.

Tanking all the inside of the walls isn't a wrong solution because you need to do something to the walls to make them presentable but I strongly suspect if the cellar can be ventilated correctly and heated most if not all the problem will go away.