one-coat stain applications with sealer and multicoat stain applications
with decorative sawcuts form the largest percentage of chemical
staining projects. However, a growing number of clients opt for
something more when they see the design possibilities with various
With some imagination and skill, concrete
artisans can broaden their horizons and take their work to the next
level. Here are some of the techniques used to create one-of-a-kind
Concrete dyes - When
concrete dyes are combined with chemical staining, there are no
limitations from a predetermined color palette or color values.
Dyes can produce bright, vibrant colors such as yellows and blues,
and applicators have the ability to mix their own custom colors.
Dyes can also soften areas where the chemical stain has produced
an overly bright tone. Or they can enhance stain colors in areas
of the slab where the stain is not reacting with the concrete.
Decorative sandblasting -
Intriguing effects are possible by sandblasting after staining,
particularly when decorative stencils are used. The stencils are
applied to the concrete surface before
sandblasting, so only the areas not covered are revealed. After
the stencils are removed, the protected areas can be stained or
dyed a contrasting color.
Some manufacturers sell decorative
stencils that are sandblast resistant and adhesive backed. Different
degrees of tack on the back are available, so choose carefully.
A high-tack backing could lift the sealer from the substrate or,
in warm conditions, transfer mastic to the surface, which could
be difficult to remove later. Conversely, a light-tack adhesive
in cool conditions may not adhere aggressively enough. For this
reason, most manufacturers recommend a coat of sealer prior to sandblasting
to improve adhesion.
Faux finishes - The
same techniques and tools that have been used for years to faux
finish walls can also be used on concrete flooring. Application
tools include rags, torn paper, plastic and sea sponges to name
a resist - A resist is anything that impedes the stain
from penetrating into the surface of the concrete substrate. Sealer
is often used as a resist, especially on projects with intricate
sawcut patterns. Once the appropriate amount of sealer has been
put down and has had suffici ent dry time, it forms a barrier that
blocks the stain or other liquids from penetrating the concrete
With some creativity and experience
using sealer as a resist, you can stretch your imagination. For
example, incorporate "veins" into floor designs by applying
sealer with an eyedropper or artist's brush prior to staining. Other
application tools include crumpled rags, sea sponges and goose feathers.
Keep in mind that not all sealers are equal, and a test panel should
be conducted to check the suitability of the resist.
Another way to resist the stain from
penetrating designated areas is with masking plastic. However, this
method is generally not practical for masking off detailed sawcut
In addition to being used as a resist,
sealers can add the final touch to a stained concrete project by
enhancing the colors you have worked so hard to achieve. You can
also choose from various degrees of sheen, ranging from matte to
Gelled-acid etching -
There are gels that can be used with decorative stencils in a manner
similar to decorative sandblasting. These gels contain acid, which
is responsible for its etching ability, but the acid is suspended
in a gel solution so its interaction with the concrete is limited
to the surface. Because of the product's gelatinous grip, it stays
on the stencil and won't bleed underneath it, etching only the exposed
areas to produce a very precisely etched pattern. These products
also will not compromise the pH of the concrete, and it will not
contaminate the sewage system after it is flushed.
Engraving - High-performance
engraving tools can cut intricate or one-of-a-kind designs into
concrete. An assortment of engraving tools guided by templates are
available in thousands of patterns and designs, including letters,
logos, borders and custom graphics. The tools can also be used freehand.
Small wheel-mounted decorative concrete
engraving saws can be used to do engraving work in small or restricted
areas. When equipped with an optional center pivot, they can also
cut perfect circles.
Fertilizer - The
iron and nitrogen in fertilizers, such as Miracle Grow, dissolve
and leave unique etchings on the concrete floor. One of the more
popular techniques is to use fertilizer pellets. Usually the pellets
are applied to
the concrete surface prior to staining. However, some artisans will
first apply a base color of stain and then apply the fertilizer
pellets followed by a second color of stain to achieve different
Sawdust and kitty litter
- When applied to the concrete surface during staining
they will absorb the stain and leave an outline on the concrete
floor. As with fertilizer pellets, sawdust or kitty litter can be
applied at different phases of the project to create different effects.
Sampling is essential to achieving the exact look you are after.
Other common absorbent materials used
to create special effects include corn flakes and metal shavings.
The possibilities are unlimited when you use some of these materials
combined with staining.
Torn paper and rags - Any
item with a ragged edge can be used to transfer the look of a vein
or cracked edge onto the floor. Stain or dye can be sprayed across
the edge of torn paper to achieve this effect. Or rags (torn into
strips) can be applied to the concrete survace and then stained
to create the look of a crack.
Air - Accents can
be created by "blowing" the stain across the surface,
using compressed air force through a fine tip. For example, by applying
stain with an eyedropper into the channel of a decorative sawcut,
and then using the air tool to blow the stain out, you can achieve
the delicate look of vines or ferns. Be aware that while using air,
some of the stain can become airborne. It is essential to wear protective
gear and safety glasses or goggles when using this technique.
If you choose to add some pizzazz
to your stain work using one or more of the techniques described,
you must practice the applications on sample boards to perfect the
process before proceeding to the big leagues on your client's floor.
Hopefully a few of these ideas can help take your stain work over
the top by separating your floors from the boring one-color application.
Harris is the founder and president of the Decorative Concrete Institute
in Douglasville, Gal, which provides hands-on training seminars
in architectural concrete. He has pesonally placed or supervised
the placement of more than 3 million sq. ft. of decorative concrete
and has authored two best-selling books, Bob Harris' Guide
to Stained Concrete Interior Floors and Bob Harris' Guide
to Stamped Concrete.
CONCRETE CONCEPTS * March 2005