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CATEGORIES:
BRICK
& MORTAR - EFFLORESCENCE
AND CALCITE - CONCRETE
BLOCK - TILT UP
CONCRETE
EFFLORESCENCE AND CALCITE
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Efflorescence
A
complex subject with no single answer I will try to break the
problem down to manageable segments that can be realistically
handled. I will not try to analyze this subject according to
scientific studies. I have not done scientific studies because
I don't get paid to do them. I get paid to solve problems, often
I am successful , sometimes I am not. |
The
terminology I will employ will be a combination of what other people
in the industry have spoken to me about and referred to and some
terms that I personally use to designate certain situations, in
any case initially I will explain all the terms I use in terms of
what I mean by them. If that differs from some one else's use of
the term that is okay from my standpoint. I don't claim to be an
industry expert merely very experienced at solving difficult problems
as regards the cleaning of buildings. . Let's begin with classifying
the different areas.
Types of efflorescence situations
1. Cleanup efflorescence: This is a result of the free chloride
ion of the acid detergent bonding with available calcium on the
surface and making calcium chloride.
2. Calcite: This is the result of water migrating through a wall
principally because of leaks allowing water penetration. It is possible
that there is within this set of efflorescence a subset as I have
seen brand new concrete block construction that experienced serious
rain soaking develop calcite very similar to brick walls with serious
on going leaks or constant water migration.
3. Lime run: I have experienced this as a steady release of calcium
soaked water that creates a streak down the wall and separately
in a situation where an overly wet grout bond beam was poured in
concrete block . My initial experiences with this problem was from
a set of weep holes in a plastic molding plant that bled lime run
constantly for years.
4. Weather efflorescence: This occurs in the winter on the outside
of walls where the inside has a lot of water vapor , such as swimming
pools or institutional dish rooms, and outside there is exceedingly
dry northern air. This dries as soon as humidity is restored and
is not worth dealing with.
5. White Scum: I do not know what this is . I have seen it several
times and I see that my competitors have a product to deal with it
so it must occur regularly. I will detail one occurrence where my
product was used in exactly the same situation as a competitors and
did not create this problem while it did occur on the buildings cleaned
with their product. We do have a product that deals with this problem
successfully.
There
are probably other situations or varieties of these problems and
each of you should feel free to call and report or detail what you
feel to be a different problem or circumstance. We at EaCo Chem
Inc. are very interested in dealing with these problems and hopefully
developing more effective means of removing them than currently
exist. I say that with humility because some of our solutions now
are not as elegant as I would like and there are no guarantees that
a better answer is readily available. After having said that I will
say that we have repeatedly solved every one of these situations
satisfactorily if not cheaply and easily.
Cleanup Efflorescence
This is the area of our greatest success so let's begin here. Much
of the concrete block industry is using integrally water proofed
colored masonry units. These units based on our experience are having
real difficulty on cleaning with this calcium salt showing up all
over the surface. That is until you apply NMD 80. The NMD 80 applied
at a 4-1 dilution does not create this problem and will remove it
if some other product caused it. There is a very simple reason for
this, the NMD 80 hydrochloric acid component is so thoroughly bound
up with the additives that it is not free to bond with the calcium
of the colored masonry units. This combination of integral waterproofing
and NMD 80 will result in stunning color clarity and ease of cleaning.
Blocks without the integral waterproofing still seem to have greater
problems with color fastness and a hazy appearance though the clean
will be just as easy with the NMD 80. Later on I will discuss one
of the secrets to dealing with the calcite on this type of block.
Occasionally some pockets of residual construction moisture will
allow a very light efflorescence to occur after cleaning. Our Ef-Fortless
is a safe product to spray on and allow to dry on the surface and
will retard the redeposition of calcium chloride on the surface
for a considerable period of time and possibly solve it forever.
When we refer to an end to cleanup efflorescence we are referring
to the use of NMD 80 to clean the integrally waterproofed c.m.u.'s.
Our experience over the last couple of years is that we have had
no failures to clean or solve efflorescence in this situation.
Calcite
This is the most difficult type of efflorescence to deal with
easily. In every situation I have personally been involved with
we were able to remove all of this. This type of efflorescence is
characterized by a hard and dirty white appearance. Most commonly
on brick it starts in the mortar joints and washes down over the
face of the brick. This and lime run was the reason I first made
EF-fortless. This product has the capability of being used on the
surface repeatedly without harm to any masonry or cementitious surfaces.
This was a necessary characteristic of any product that was to be
used to remove Calcite as it was often very thick and seemed to
come off in thin layers one application at a time. If the chemical
was not safe for the surface the damage from repeated applications
would have been more harmful that the original problem. This is
the reason that raw hydrochloric acid is not generally a good solution
for this problem. Since the reformulation of GS Restoration (GSR)
a few years ago we have found in numerous situations that a couple
undiluted applications of the GSR opens the pores of the very heavy
calcite and some lime runs allowing fewer applications of the undiluted
EF-fortless to totally clean the surface. I have done these type
of removal jobs with and without a pressure washer and have had
success both ways. Unfortunately I don't get involved in enough
big jobs like this to do a really good study of the difference in
effectiveness in the removal process with a pressure washer. I will
tell you this, in the hundreds of cleaning jobs I have done or been
involved with I believe that almost never have I seen efflorescence
caused by the amount of water that is put into the wall from a pressure
washer. This type of job does not tend to be inexpensive to accomplish.
As an inventor of the chemistry when I was involved in these jobs
I did not focus on the cost of removal, just on the effectiveness.
We are now generally experiencing a situation with the combination
of the GSR and the EF-fortless that these jobs seem to be more cost
effective. This is the area that I would most like to experiment
in so any one with a serious problem in western PA that can allow
time to test, feel free to call and we will show up. This offer
because of the nature of the testing program is not available in
other areas of the country. I mentioned earlier one of my tricks
to solve nightmare situations, that is to seal a very calcited block
wall before attempting the removal. This seems to isolate the melting
chemistry on the surface and allow it to react just with the calcite..
In the past a have used a solvent based siloxane as the sealer.
I will not use this system on brick in general as the two chemical
system usually is reasonably effective. One of the secrets to any
calcite removal is that you should spray on the remover and allow
it to sit on there while you spray other areas. Scrubbing the chemical
on is not cost effective. Tests should be run when using GSR to
determine color fastness of the surface. If it appears to mark either
rinse it quickly or just use the EF-fortless. If the calcite is
on concrete walls or exposed aggregate panels the above techniques
may be employed or you can try NMD80 at 4-1.
Lime Run
Generally lime run is treated just like the calcite though it can
be easier to deal with and usually does not need an application
of GSR first. Lime Run caught early enough can be dealt with in
the normal washing process with NMD 80 at 4-1 dilution. While NMD80
is the height of safety in new construction cleanup, because of
it tremendous release characteristics and buffered structure, it
is 80% HCL and many repeated applications to a masonry surface will
begin to etch. This is usually not an issue because the NMD 80 cleans
so efficiently at 4-1 dilution it does not have to be used repeated
times on the surface.
White Scum
This also appears to be the result of a new masonry detergent reacting
with brick but the salt formed is different. At Fort Bragg in NC
a set of 8 barracks all built of the same brick by the same masons
and cleaned by the same contractor had a dramatically different
result when cleaned with a different detergent. Four of the barracks
cleaned with NMD 80 turned out fine with no problems, four cleaned
with Brand X's no. 1 product all developed white scum. It became
obvious that Brand X has a white scum remover in their line because
their product creates white scum. The contractor was able to remove
this with our Glazed Surface Restoration. This product was developed
to clean glazed brick without burning the finish so it is very safe
to use but it can burn in extreme circumstances and is often used
as a concrete brightener in parking structures so be sure to test
color fastness or bleaching before using the product.
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