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?
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.
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.
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
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
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.
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
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.
On 18 Jan 2004 13:14:27 -0800, email@example.com (SuzySue) wrote:
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
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.
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
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
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
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
anti "new fangled" stuff, he likes good old fashions (50 years+) proven
On 18 Jan 2004 04:27:19 -0800, firstname.lastname@example.org (SuzySue) wrote:
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?
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.