but that has nothing to do with reality at all. It is singularly
ineffective, the fluid merely takes the paths of least resistance.
What does make a difference for a while is replacement of the plaster,
removing salt laden and putting on fresh. This is why there were no
complaints with the company that injected water - they replastered.
Bricks are porous, the pore sizes vary widely. Simple physics tells us
that an injected fluid will follow the path of least resistance, which
is via the biggest pores. The idea that injecting something can make a
brick waterproof or vapourproof just doesnt fly. Show us some support
for your claim, perhaps some evidence. If there is none, I can think
of an easy experiment using food dye mixed with the fluid, and the
brick sliced up once dried out.
I'd rather believe that there's a good reason we build houses with damp
courses. Flying in the face of 100 years worth of experience might be
seen as being a trifle loopy.
I've never seen RD but I don't doubt it exists. I've never had smallpox
It comes from "Moisture Movements in render on brick wall" KK Hansen, TA
Munch, PS Thorsen, C Villumsen, LC Bentzon; in Research in Building
Physics By J. Carmeliet, Hugo S. L. C. Hens, Gerrit Vermeir; Pub Taylor
& Francis, 2003 ISBN 90 5809 565 7.
The paper cites the most common pore size in fired bricks as 2000nm.
There may be pores musch larger than 4200nm, but the important factor
for wicking is the size of the pores in continuous contact through the
matrix of the brick.
There's something that doesn't sound quite right.
Isn't that reference about render? In that case, they mention the higher
porosity (at least a factor of 10) of render, and that appears to be one
of their points. Also, it's to do with penetrating (largely) horizontal
damp through brick, rather than vertical travel. This page is interesting:
It obviously rabidly anti rising damp, but contains some interesting
photos (including brick walls in water without dpcs - anyone living near
a canal can see similar) and references.
I used to regularly run thin layer chromatography plates in which the
water phase rises along the plate by capillary action. The plates were
about a foot long and the water made it all the way to the end of the
plate. These were only run for short periods.
I'm led to conclude that the absorbent materials that you used either
permitted evaporation at such a rate that liquid couldn't rise very high
or that the pore size in the absorbent material was much larger than you
Besides, you're turning blind eye to the fact that capillary action can
(and does) raise water over well over 10metres in trees.
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember The Natural Philosopher
I have direct experience of this in my last house - a 1920s cottage
where the walls were mass concrete and no DPC. The site was on the edge
of a drained and filled duck pond, according to locals. The lower
internal 6" of the front wall was definitely damp - not enough to blow
plaster, but not dry. Surrounding the cottage was a concrete path which
ran right up to the walls; it was definitely below floor level, by a
couple of inches.
So, imo, the only place the damp was coming from was underneath the
wall, iow, the ground.
Oh, the same local who told me about the duck pond also mentioned there
were no foundations as such, but the walls were about 20" thick, so I
suspect they weren't needed.
Ah yes. Rain splash in the middle of a house miles away from any
exterior wall is always the obvious reason.
And you get tons of condensation in the middle of a hot summer with the
windows wide open don't you?
What's it with you? You are like Hansen, no matter what the evidence is,
your Faith triumphs over Reason..
I dont recall claiming it doesnt exist, merely that nearly all cases
of damp at the base of walls weren't rising damp.
This is all too familiar. If you'd done your reading you'd have known
that the BRE experiment shows that it does exist.
I have experianced rising damp. Our last house was built sometime before
1835, the morgage lender insisted that the 9inch solid brick walls have damp
course treatment. All remained damp free except an 18inch section of a front
outside wall and a 3ft internal dividing wall. The damp proofing company
were called back under the garantee period and admitted the insde wall had
been missed on the original treatment and fractured bricks had caused a
break in coverage of the fromt wall. They re injected these sections, after
which we had no more rising damp.
The damp in these areas could be clearly seen by a wavy line of bubbling in
the internal paintwork.
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