Is it possible/difficult/expensive to repair rising and penetrating damp in a *stone* house?
With a block or brick house, each brick can be taken out along the bottom and damp proofing put in. If the house is made of brick or block then there is a good straight line to lay the damproof down. Whereas with a stone house I guess there wouldn't be a good straight.
Also, what is the difference between rising and penetrating damp?
SuzySue wrote on 18/01/2004 :-
I don't hink in practice this is the way it would be done (removing the bricks). The modern way is by drilling holes at regular intervals and injecting waterproofing chemicals into the brickwork. I would suggest this would also work in stone.
Rising damp is er, rising. It comes up from the ground rising through the fabric of the building. Penetrating damp is that which find its way in horizontally and at any level of the structure.
People I know that have stone houses do nothing about the penetrating damp but all the houses have several dehumidifiers going all the time. (cornwall)
MrCheerful
Umm. Yes and no, in that if teh stone isn't poyrous, it won;t, but conversely neither wikll riding damp :-)
The bigger problem in some stone hoiuses is penetration via the mortar.
Yes. One potential way to deal with a damp lower storey - a reasonable cluse taht risng damp is there - is to line the lower half obf teh house internally with a waterproof membrane, and rely on the water evaporating way from the walls outwards.
This assumes the stomne is not a 'feature' of artitisctic merit inside. If it is, why is it plastered anyway? :-)
What about the method which I think is called "electro osmosis", where a cable is installed at the base of the wall and a small current which runs through the cable is supposed to prevent the rising damp.
Is this a better and/or cheaper option?
I've heard the option of drilling holes and pouring in liquid is not always 100% perfect as the liquid may not form a prefect seal.
It works brilliantly. I had it installed on a stone building a few years ago with great results.
Water rises through small capilliaries in porous material. It will go to about a metre above the ground if there is no damp course.
Penetration can occur if the material has aged and failed or if there is a source of water from above that isn't catered for in the original design.
Assuming you have not radically altered the design of the house or changed the ground level outside it by gardening/new roadworks/dumping rubbish etc, the fabric of the building is not likely to have failed.
Therefore look for cracks and loose guttering, missing tiles and all that sort of stuff. Check if neighbours have that problem or is this a new one on them etc. Then report back.
They tend to combine it with "tanking", i.e. a supposedly impermeable rendering. I had this done over about 20 metres of a rubble stone limestone house built on limestone half way down a hill. About 3/4 has worked, the rest hasn't. In the wet part, the electrical part is "live", you can sense the voltages with a DVM. But it didn't cure the damp there. My fix is going to be a "feature wall", i.e. pointed rather than rendered. With the rendering stripped off it stays dry to all visual intents and purposes. But it was very damp when "tanked".
SuzySue wrote
You might get better results by shouting at the wall and hitting it with a branch like Basil Fawlty. Seriously, it is the least reliable of all damp-proofing systems. Sometimes it works but nobody has been able to understand why. In the vast majority of cases it doesn't. And don't be fooled by sales pitch about active and passive systems - neither is better than the other.
There is also the high capillarity tube system, where a row of highly porous ceramic tubes is inserted into the wall, the idea being that dampness is sucked out of the wall and evaporated in the tubes. This system has been frequently used in conservation work and has been proved to be effective in many cases, but often only for a limited period. It results in deposition of hygroscopic salts inside the tubes, which greatly hinder the evaporation and after a time actually work in reverse by attracting vapour. To be truly effective, the tubes need to be replaced every 5 years or so.
This is true - the process of injecting silicon under pressure can result in the liquid finding voids in the wall and draining down into the foundations rather than dispersing into the wall. This is very common in random rubble stonework. One company, Peter Cox (now Terminix Ltd), developed a patent process to prevent this - their system involves using sponges in the holes in the wall and pots of liquid which drain into the wall slowly by gravity, rather than being injected under pressure. It is supposed to be far more reliable in stonework than the pressure injection system, and I have specified it for many stone buildings in the Oxford area.
In very soft stone, or in cob or whitchert construction using rendered mud, chemical dpc's are usually hopeless. But if the stone is hard, like granite or slate, then it will be impervious and will itself prevent rising dampness (slate is commonly used for physical dpc's). But because of this, the joints in this type of stonework are usually found to be very badly affected, and often damaged, by both rising and penetrating dampness. If this is the case it is vital that these are repaired properly, ideally with lime mortar.
Out of all the choices, the liquid system has the highest success rate, and this is much more likely if the organic solvent system is used rather than the water-based system. In very damp walls the water-based system becomes diluted and takes forever to dry out.
HTH Peter
Maybe, maybe not... need to know a bit more about your particular house!
What stone is your wall made of? What is the construction?
J.B.
In article , Michael McNeil writes
No it won't. Don't be silly.
Perhaps not a metre. But I can show you it going to about fifteen inches. Please don't make comments about rising damp not existing.
I can show you a property where the moisture has risen well above the metre mark on the walls, and I can assure you it is all from water rising up and not from water running down.
I looked into this, and none of the compaines I found would offer a guarentte it world work, beoynd money back, installation is more than the things cost. None of them could find me any property where the system had been installed and got through building regs, as a "damp proof layer" when repairing an old building.
Rick
I have an old slate house, with damp. What works depends on how your house was built, and what stone it is, and what soil you have, and what mortar you have, and has the mortar been messed with by re-pointing, and has someone tried to waterproof the walls ?
I am going for one solution, as I will be doing significant repairs and alterations, my house is built into a hill.
The house has been "dug out. A waterproof skin will be stuck onto the outside, and a french drain used to stop hydrostatic preasure (water build up) on the outside.
Most of the systems change the look of your house, some in a terrible way.
Chemical solutions depend upon the type of stone.
I have a stone floor laid on soil, and the damp comes up through that too, so just fixing the walls may not be enough.
I found an local Architectrual engineer, he is not an arty farty designer type, he understands buildings of my type in my area. He has been really usefull, but is very anti "new fangled" stuff, he likes good old fashions (50 years+) proven solutions.
Rick
I was speaking with a "damp specialist" on the phone and he informed me that putting a membrane around the walls is the option to go for in a stone house.
He said the injection method is not usually used (or maybe he said it's not effective - can't recall) in stone houses.
Anyone know if this is true?
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