Concrete
Polishing�A top contractor’s tips to producing the perfect polished floor
Jim Cuviello of Complete
Decorative Concrete Solutions (CDCS) in Annapolis, MD, sent in this
informational account of a stained and polished commercial concrete floor
project. Read on to find out the step-by-step procedures followed including tips
and information on grinding, honing, polishing, staining, equipment used, and
more. The Complete Decorative Concrete Solutions team consisting of Pete
Cosgrove of CDCS, James Stephens of Heavenly Touch Stone Care of San Jose, CA
and Giovanni Lagana of Lagana Tile
in Monterey, CA,
who flew
to Annapolis to lend a hand in the polishing process and hone their skills in
concrete staining techniques.
The Lavina 25, 7.5HP,
machine and diamond abrasives came from Mile at Advanced Diamond Tools in
Canada. To collect the concrete dust the Pulse-Bac system from CDC Larue was
used. All the saw cuts were done with the Mongoose 411 from Engrave-a-Crete.
The “Polishable Concrete Densifing Stains� are from Seal Source
International.
The job is a 3,600
square foot tanning salon with six, 600-square-foot sections that are stained
orange, brown, green, a blue/green combination and two shades of blue. There
are sawcuts throughout the 3,600 square feet. When the floor is completed,
walls for 22 tanning rooms, a lobby, office, laundry room, and bathroom will be
installed.
Managing the customer’s
expectation through the project is as important as the work itself. It is
important to keep the customer involved throughout the process so they can see
the progress and build an idea throughout the project what the end result will
look like. This way there are no surprises because the customer had
preconceived ideas of what the end result was going to be.
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Tanning salon floor prior to staining and
polishing.
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Before starting any job
try and find out the specifics of the concrete mix that was used for the slab.
This will not dictate the overall procedures but will help decide the best
course of action. Often this information is not available and you are left to
trial and error. This particular concrete slab was a fiber reinforced concrete
that appeared to be soft.
Since this slab was going
to be stained the goal is to expose as little aggregate as possible and reach
the most refined cream within the surface. This will allow for the best stain
saturation and true color of the stain.
It is the precision of
your initial grinding that largely sets the stage for the quality of the
completed job.
In a commercial
setting, there are typically two or three different “layers� of concrete within
the surface cream before exposing aggregate ¼-inch or larger. The surface cream
on this slab had three layers. The top was a burned hard troweled surface with
fibers sticking out like fur. The next layer was a refinement of the hard
troweled surface. The last layer is lighter, even in color, and consists of
very small aggregate/sand the size of a pin head and a little bit larger, about
1/16 to 1/8-inch. This last layer is the purest. It is the most consistent in
color and has the most imperfections removed before exposing aggregate ¼� and
larger.
Close-up of floor surface and the various layers in the cream.
Different from restoring
and polishing marble/granite floors, these layers are a key element when
polishing concrete when exposed aggregate is not desired. When restoring and
polishing marble/granite there are no distinct layers, per se. There are
variations that go through the whole stone not just in the surface. With
concrete, if expose aggregate is not desired and the goal is to work within one
of the layers, you have to be careful not to grind through that layer. The goal
is to refine “to� and remain “within� the desired layer and make it as
consistent as possible throughout. These layers can vary in thickness through
the surface of the slab.
Finding the right diamond
combination on the first day sets the pace for the rest of the job. Diamond
combination is not just referring to sequence of grits but the actual style of
diamonds - ones with more and less surface area. It provides a base to work off
with the ability to change as needed. Once the surface is ground off there is
no putting it back. For the most part, once a good set up is found it can be
carried through the whole job. Although, be prepared to possibly get thrown for
a loop and find an area that the predetermined set up does not work. This is
when you go to your “tackle box� of abrasives and “slowly� figure out what is
needed to finish that area. Always watch the results while working specifically
in the initial grinding steps.
It is our preference to
start and finish dry. If possible we prefer not to deal with wet concrete
slurry. We started by grinding dry with 220 grit, Metal Super Thick Abrasives
from Mile at Advanced Diamond Tools. When trying to cut the slab the 220 grit
abrasives would leave various light scratch patterns but not actually cut. The
concrete seemed like warm plastic. The heat from grinding dry had partly to do
with this although the diamond tooling never glazed. After attempting other
diamond sets dry (ones with more and less surface area and different grits), it
was determined we had to go wet for our initial grinding steps.
Once again we started with
220 grit Metal Super Thick Abrasives (wet) and found it was removing the burned
troweled surface but very slow. Keep in mind we did not want to go to
aggressive, we wanted to find that sweet cream that would allow the stain to
saturate to its fullest potential. In addition we wanted to eliminate as much
crazing/webbing/micro-cracking as possible.
Our passes consisted of
up/back and up/back over the same area. Sometimes depending on the levelness of
the concrete, we would go over the area a total of four times but at different
angles. It is better to take extra passes removing a little surface at a time
then go with a more aggressive diamond taking less passes only to find out you
took too much off.
Just a note, there is no
reason you can not stain a slab with exposed aggregate when using the Seal
Source International water-based Densifing Stains. Most aggregate will not
absorb the stain or will do so very little. A stained aggregate floor can be
very decorative.
Since the 220 grit metal
took a lot of time we went to the 120 grit Cementina Metal Bond Diamonds from
Mile at Advanced Diamond Tools. Again this went a little slower than we wanted
so we went to the 70 grit Cementina Metal Bond Diamond. This gave us great
production without exposing aggregate. The fibers sticking out were not a
concern because they almost always get burned off the surface during honing and
polishing. The first four 600 square foot sections of grinding consisted of 70
grit Cementina Metal Bond Diamond then the120 grit Cementina Metal Bond Diamonds
and finished with the 220 grit Metal Super Thick Abrasives. All three of these
grits were done wet.
When starting the fifth
section we took one pass with the 70 grit Cementina Metal Bond Diamonds and went
straight through the burnt surface, the sweet cream, and a good bit into the
aggregate. In simple terms this section was very soft and cut much easier. On
the technical side the metal matrix of the pad responded in a manner that
allowed the diamond abrasives to cut quicker. This will be left for another
day. Usually, you have clues such as color variation to the hardness of the
concrete. Unfortunately, there were no clues. We immediately stopped; put on
the 220 grit Metal Super Thick Abrasives and made our up/back, up/back passes
wet. We found the 220’s cut consistently but not very quick. We then tried 120
grit Cementina Metal Bond Diamonds and the 120’s cut great but found up/back,
up/back took too much surface off. I said earlier, it is better to take more
passes and time then to take off too much surface at one time. The 220’s would
have worked but would have taken way too long and the 120’s were too aggressive
to take a little off going up/back, up/back. We looked in our tackle box of
abrasives and did not have anything that would allow us to cut slowly using our
up/back, up/back method. One of the reasons for using this up/back, up/back
method is that it allows for further refinement of the surface on a microscopic
level than if you were to go with a more aggressive grit passing over the
surface quicker with less passes. The result of a more refined surface as you
work through the grits is a surface that when done gives you better depth and
clarity of reflection. It will also give you a better chance of having depth
and clarity of reflection looking straight down on the floor than having to look
across the floor into the distance. Since we did not have any abrasives “on
hand� (Our answer was probably the 220 grit Cementina Metal Bond Diamonds but we
did not have them on hand.) we had no choice but to use the 120’s and make two
one-way quick passes in different directions to make sure we hit all the little
dips. We then moved up to the 220’s and continued with our up/back, up/back
method. In some areas we took another up/back pass to get the most refinement
possible.
Always be ready to
switch up your procedure when needed and always pay attention to the details as
you go. We stayed with this current set up going into the sixth section and as
it turned out this section was the same as the fifth. For the last two sections
the combination we used was 120 grit Cementina Metal Bond Diamonds making two
one-way quick passes in different directions then the 220 grit Metal Super Thick
Abrasives going up/back, up/back wet. In some areas we went up/back one more
time with the 220’s to allow for further refinement of the surface.
Once all 3,600 square feet was
ground to 220 metals, we thoroughly dried it and went to 100 grit phenolic
resins dry also from Diamond Tools in Canada.
The back of the floor was ground to 220
metals and the front to 100 resins.
The floor is still damp in some areas in the front from auto scrubbing.
You have to think of a
jobsite as a puzzle. There are a lot of steps involved in bringing a project
from start to finish. There is running the equipment, cleaning the floor,
laying out the design if there is one, getting the customers approval,
sawcutting, if needed stain samples, etc. When one step is being completed by
one person, such as grinding, then someone else can be completing the next step
such as cleaning that same area. And at the same time, more people can be at the
other end of the slab, completing more steps that may be completely independent
of what is currently going on, such as design work or stain samples. In
addition, everyone should be thinking ahead. For example, when it is ready to
change the diamond abrasives, someone is standing there waiting for the machine
to be lifted to make the change. The jobsite needs to run like a well-oiled
machine so that production is at its maximum.
As each section was
being finished with 100 grit phenolic resins they were also being cleaned with
an auto scrubber. It was being determined where the walls were going to go and
samples of the stain were being applied and polished with a hand grinder to get
the customer’s approval.
Color
samples of the stain were applied and polished with
a hand grinder to get the customer’s approval.
Polished stain samples.
Keeping in mind that the
customer was approving the general color, not the exact color, because the
stains’ true colors will vary throughout the slab according to its porosity.
What also partly determines the porosity is the grit you stop at before
staining, what layer of the concrete the stain is applied to, and the variation
at which the diamonds hit or did not hit in the low and high spots. If need
these low spots can be refined with hand tools. In addition, the concrete will
dictate how the stain is absorbed as a result of the mix, how it dried,
finishing methods, etc.
Now that it had been
determined were the walls would go, it was time to layout the rest of the floor
for sawcuts. Next the half circles and sun rays were laid out. The center
point of the lobby was found and the half circles were drawn with a picture
frame wire stretched out with caulk taped to the end. Picture frame wire was
used because it does not stretch and is flexible. Once the floor was laid out,
the Mongoose 411 saw from Engrave-a-Crete was used to cut all the lines. All of
the lines were cut free hand!
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The Mongoose 411 from Engrave-A-Crete was used to cut all the
lines of the floor designs.
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Once all
the sawcuts were cut, a RotoZip router/saw was
used to finish off all corners so that the lines connected clean. |
In the past we used a
grinder with a 4� blade and metal straight edge to finish off the lines. This
job had some small detail work in the rays that need attention that a RotoZip
took care of. The RotoZip can also be used with a small circular blade. It is
much easier to use then the hand grinder. This tool allowed us to tighten up on
all the sawcuts throughout the entire floor, much more so than using the hand
grinder.
Details, Details, Details
make the difference between a good job and an exceptional job!
Now that all the cuts were
complete and the floor was as clean as possible it was time to start staining.
The stains we used are Densifing Concrete Stains
from Seal Source International that are water-based. There are no hazardous
acids or solvents to deal with, and the application cannot be any easier. There
is no need to wear extensive protective clothing or face masks.
The stains are unique in that the carrier of the pigments is a
concrete densifier so the concrete gets densified
and colored at the same time. Concrete densifier helps polished concrete
retain its shine because it makes the surface more abrasion resistant among
other properties. The stain is quick and easy to apply cutting out several
steps that other polishable concrete stains have to go through to obtain the end
result.
Simply, apply the stain to the desired color shade after 100 grit honing
with phenolic resins. Apply a touch more stain in anticipation of a little
color lifting out during honing.
Stained but not yet honed and polished.
Stained but not yet honed and polished.
Once the stain was dried we
moved on to 200 grit phenolic resins. If you have never stained and polished a
floor before it can be a bit nerve racking to watch the floor turn almost white
as the 200 grit phenolic resins move across. At 400 grit phenolic resins some
of the color came back.
At 800 the floor popped
and more color came back.
Finished at 800 grit.
At 1500 we had
great clarity, the floor looked tight and the color came back.
Finished at 1500 grit.
Walls during assembly unfortunately with all the
construction they are very dirty.
Walls during assembly unfortunately with all the
construction they are very dirty.
Complete Decorative Concrete
Solutions
Jim Cuviello
408 Kings College Drive
Arnold, MD 21012
(410) 626-7471 Office
(410) 544-0875 Fax
Send Mail Now - Click Here
http://www.floor-care.com
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 | | Marble | MARBLE: CHARACTERISTICS
This standard includes general information on the characteristics
and common uses of marble and identifies typical problems
associated with the material.
INTRODUCTION
Marble is an extremely hard, metamorphic stone composed of calcite
(CaCO3). It is formed as a result of the recrystallization of
limestone under the intense pressure and heat of geologic
processes. The effect of this process is the creation of a stone
with a very tight crystalline structure and small but definite
porosity. Because of its structure, marble can take a very high
polish and is a very popular decorative stone for architectural and
sculptural uses. The limited porosity of marble, especially
polished marble, makes it less vulnerable to the leaching effects
of water. Calcium carbonate, however, of which marble is composed,
is highly susceptible to attack by acidic agents. Marble is
readily dissolved by acids, even very dilute acids, however the
actual results of acidic exposure will vary with the nature of the
acid. Chlorides, nitrates, sulfates and other chemical compounds
react differently with marble and produce various by-products,
which have a wide range of solubility and impact on the durability
of marble. For this reason, it is always important to determine
the exact type of pollutants causing marble deterioration.
Marble itself can be of two types, one composed of calcite and the
other of dolomite. Dolomitic marble is much more resistant to acid
attack than calcite marble. The color of marble ranges from the
brilliant white of calcite to black, including blue-gray, red,
yellow and green, depending upon the mineral composition.
TYPICAL USES
Marble has many decorative and structural uses. It is used for
outdoor sculpture as well as for sculpture bases; in architecture
it is used in exterior walls and veneers, flooring, decorative
features, stairways and walkways. The way in which the stone is
used may be a factor in limiting or controlling the severity of
exposure. The use or function of the marble may also affect the
feasibility of applying certain treatments, but type of use is not
the primary factor in the major types of deterioration and damage
to which marble is susceptible. | |  |
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Re: Prestigeous article 
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