CREATING BETTER IMPRESSIONS
How To Get The Best Results From Stamping Concrete -
thats just right: when finishing stamped concrete, you can't
have the mix too soft or too hard. It has to be
just the right consistency. Too wet and the concrete pull the
stamps, leaving suction marks. Too dry and it will not leave
embossment or impression.
concrete mix needs to be workable but not excessively wet, between
4.5 inch slump. As the
season progresses, and the
weather gets warm, a decrease in the slump helps to compensate
for evaporation. A lower slump can also prevent oozing between
on every load poured gives you consistent color and texture.
As with all concrete, weather and sunlight
hardness, which also affects color and texture. When setting
up a job partially in the shade and partially in the sun, try
it in two pours.
a consistent impression: 4 inches of aggregate base, and the
before placing concrete,
a more consistent finish and prevent efflorescence.
detailed stamps require creamier cement; adjust by adding a little
color on the top of the cement. Color gives
a slightly fattier surface or a creamier base.
use of a texture roller or lambs wool paint roller to smooth
marks that can result from stamping wet concrete.
jointing rollers can be used to knock down suction marks, smooth
ridges and clean up the joints between the stamp patterns.
is essential in patterned concrete work. Depending on the time
you'll either have to speed up or
slow down to achieve a nicer stamped impression.
important factor is to know your stamps before you get to the
Do a dry run before you pour so you know how these
stamps are going to interlock. Be aware that the stamping tools,
if left too long on the slab, draw moisture, affecting the
color and texture.
tool selection can help you reduce repeats in the pattern. Some
such as the European fan pattern,
designed to be used throughout an entire pour, repeating over
and over again. But a visible repeat, in an ashlar slate for
example is very undesirable. Label your stamp patterns using
B and C, or different colors as blue, yellow and red. Interchange
these different patterns frequently throughout the slab.
unwanted lines by turning patterns in a 45 degree angle. Also
banding with a contrasting color or texture will help break
up a large field. Borders can also help downplay slight color
variations that can result from different pours. Larger stamps
can break up
noticeable lines that develop on large areas.
use of admixtures can help minimize the problems caused by weather.
for cold weather, retardants for hot
can buy you the extra time you need in these conditions.
useful product is an evaporation retarder. Especially in the
fall and spring, when the sub grade is still cold,
you have windy conditions and a hot sunny day. The cool
ground makes the
concrete mushy in the bottom, yet the surface is setting
fast from the sun. Now with a little wind you have a real
problem. The evaporation retarder is a spray on product
in the very
of finishing that can help a great deal when we are faced
with this situation.
out for crusting and surface cracking with high-range water reducers.
use of tamping tools allows the use of different amounts of force
the areas of the slab that have not set up
consistently. A tamper is also a great tool to remove footprints.
Tamping tools can range from the standard square 10x10 inch,
to a thin 8 inch round piece made out of plywood, when you don't
want to leave an outside impression.
dealing with different elevations, or when the slab roll up and
down, a 2x10
or 2x12 pieces
of lumber can be used to seat
the stamping mats. When the concrete is very fresh, lay the mats
out, keeping them as tight as possible, then instead of stepping
on the mats, lay a strip of lumber down and walk on that, distributing
the weight more evenly.
face it. Concrete is going to crack. But controlling those cracks
with properly designed control
joints to aesthetically enhance the slab is the key for a successful
are pre-planned cracks, which primary job is to break up the
slab into geometric
patterns to cause it to crack in a uniform
way. The whole trick is to fool the eye into seeing beauty, not
imperfection. You can use the joints as part of the decoration.
The more you carve it up, the fewer the random cracks. But fashion
should never take a back seat to function. Joints perform a vital
function in concrete work. You don't tell concrete what
to do, it tells you what to do.
your joints before the pour, and then incorporate a pattern into
You may score or saw cut
joints, add a colored seal, or
use a grooving technique to distress harsh lines.
trick is to incorporate metal as brass, copper and stainless
joints components. It's strictly for aesthetics,
but it's still functional.
control joints by incorporating them into the design with complementary
bands and borders.
Liquid release agent is quickly becoming the obvious choice
demand for quicker turnaround, cleaner jobsites,
and environmental concerns.
The most common way to achieve color highlights is to add an
directly to the liquid release
before the texturing
process begins. Adding a powdered release agent in small amounts
is a clean and simple way to achieve this goal. This way the liquid
release acts as carrier for the powdered color, which is already
formulated and easy to use. Depending on the size of the project,
consider mixing the pigment in the liquid release that will cover
the whole area to achieve uniformity.
the liquid release to the stamping tools and to the concrete
surface with a low pressure
sprayer and set it to a fine mist
so you will avoid over-apply. Keep on moving the stamps as normal.
As you move the texturing tools, you'll find that some of
the pigment will lift with the stamps. Compensate this by misting
the liquid release lightly over the already textured areas to even
out the highlighting. After the texturing process has been completed,
apply a touch up coat as needed.
the liquid puddles it should carry the pigment into the relief
of the texture and the
joints, where you want the highlighting.
The liquid release should evaporate within 12-24 hours, depending
on the ambient temperature, leaving the pigment added on the
- Make sure
that you mix the dry pigment thoroughly before adding the solution
to the sprayer.
- Test your
sprayer off the slab to ensure color dispersion
to shake your sprayer from time to time to keep the pigment
start with a light solution. Darken as necessary.
- Do your
detail and touch up work, before you re-apply.
samples using this method whenever is possible
- Use caution
not to begin stamping too wet, as impacting of the release
Concrete Patterns & Colors