Rising damp

[RogerS]

My point is that a dehumidifier will work like a sponge and will draw the water out of the walls...which will then, by capilliary action and rising damp, suck up more moisture from the soil to replace that which has been sucked out by the dehumidifier.....which will then suck this out...which will then be replaced...you get the picture.

if you want to decorate internally there is some very good thing skinned and structrually stable sheeting that you mount onto the wall. No studs needed any more - very thin. You can mount picutres on it and also small cabinets.

 

[tim]

I don't think you are correct. We have a 200 year old house with 3ft thick stone walls. The old folk who lived there before us had had the house rendered and put anaglypta up inside (nice!). We knew the house was damp - took off the render and the anaglypta, removed the rotten plaster, replastered and used a dehumidifier. We have no damp course.

After running the dehumidifier constantly for 6 weeks the humidity dropped from 85% to 55%. If your theory was correct then the humdidity would stay constant. We now only run it when the indicator shows humidity over 65% - runs overnight and back down to 55% for a couple of months.

T

 

[RogerS]

Hi Tim

I think that we're probably both right. If you didn't run the dehumidifier then presumably the moisture would remain constant at 65%. Sucking the water out with the dehumidifier reduces it to 55%.....which then gradually over time, dependent on rainfall, hygroscopy etc will rise ...which is my point...agreed that it will take time.

Hoisting myself with my own petard we too live in an old house (near Cradley on the Hereford/Worcs border) without dampcourse and there is damp in one wall and so I have to 'fess up that you've got me wondering about trying a dehumidifier!

Do you measure the humidity in the wall?

 

[tim]

Sure but the point is its the atmospheric humidity and ground water pressure that increases the humidity over time not the fact that dehumidifier is sucking up water otherwise you would see it rise higher than before and quickly after turning it off.

You said that you sent me a PM in another thread - haven't got it.

T

 

[RogerS]

Yes..I see it..you're right. In the PM I asked where you were in herefordshire since I live on the borders. Just curious.

Roger

 

[frank]

terry said (waiting to be tapped) . rising damp get it (groan) , :lol: :lol: :lol:

 

[Knot Competent]

Roger I understand your theory, but I need to take action as the present situation is driving my wife nuts. No, it isn't just me that is sending her that way!

So, the cheapest action to start with is the dehumidifier. After that is the stripping of the walls up to 3 feet minimum, and replastering with the previously mentioned lime plaster. That will cost a lot of money, even for our small cottage, and I can't even begin to think of the upheaval involved. So I'm going to try the much cheaper option first - a B & Q dehumidifier and 2.5p per hour to run it. If your theory is proved to be correct I haven't lost very much.

Regards, John

 

[Melville]

the system Noely refers to is called Electro Osmosis and works by putting a low voltage current around the property. This is then taken to earth via copper earth rods where it forms a magnetic field to hold damp at bay.
The firm called Rentokill may give you more information.

When plastering after installing a d.p.c remember not toplaster to the floor or the damp will jump the d.p.c through the plaster.

Rising damp does not normally go higher than the local water table ,so anything higher than this is probably latteral damp, which is solved by a good pointing job, good luck.

 

[RogerS]

There is also a Dutch system alled Schryuver or something similar. If you are interested I can try and dig out the correct name.

They have developed further the old porcelain pipe insert concept.

They use a small rectangular insert put at intervals into the outside wall. They are very discrete and small and not obtrusive. Inside the rectangle are, I guess you'd call them baffles, that make any air/wind passing over the rectangle create a venturi effect thus drawing out the moisture from the walls that way. The Dutch use them inside their basements to great effect and given that the majority of the netherlands is BELOW sea-level I guess that speaks for itself

I know that there are some Dutch members of the forum and maybe they can add something?

 

[Knot Competent]

That sounds interesting, Roger. I'd be grateful for contact details.

Regards, John

 

[RogerS]

Hi John

I was afraid you might ask that Not sure where I might have any details left..possibly at anotehr location and I won't be going there until March 8th.

Alternatively, you could try emailing the guy from the netherlands who posted recently with the topic BORED!! Give him something to do :wink:

Roger

 

[RogerS]

John

Here you go

www.schrijver-systeem.com

Roger

 

[Mcluma]

Looks very good

 

[RogerS]

yes it does and has got some awards. I looked at it a few years back for another building but for other reasons never took it forward. Intriguinlgy they were offering a guarantee then..which they hint at on the home page but i could not find any reference elsewhere

Roger

 

[Knot Competent]

Roger, you've come up trumps. Thanks for your time.

Interesting idea, but the letters of commendation from existing customers seemed less than whole-hearted - seemed to be saying "less damp in places, but early days yet". As the company have been marketing in the UK for some years I'd have expected more complete stories.

Thanks again, but I'd rather install something like that myself, at a much lower cost. Shame they don't sell the units to those who enjoy doing their own maintenance.

Regards, John