Stain manufacturers differ
on when to apply stain. Some say that a new slab must
cure for 28 days before work is started. Others suggest
14 days. Installers sometimes prefer to do their work
as soon as possible after the concrete is placed.
When choosing how to apply stain, keep the following
things in mind:
are more intense if stain is applied soon after concrete
is placed. Stain diluted with water and applied immediately
can often achieve the same results as full-strength
stains applied later.
• Water drives the chemical-stain reaction.
To achieve color consistency, make sure the moisture
content of the concrete is roughly the same for every
placement colored. If one concrete placement is stained
2 days after it’s placed, then other placements
should be stained when they are 2 days old for color
• Staining, sealing, and covering finished work
before other construction trades return to the area
saves on cleanup, achieves a better-looking installation,
and makes damage repair during the rest of construction
easier to handle.
There are many ways to apply stain, with each method
providing a different final appearance.
However, there are some general guidelines.
Sprayers often are used to apply stains, but they
should be rated for acid and have no metal parts.
Acid will quickly destroy metal parts, which can affect
the color of the stain. Miller advises using a spray
tip with a circular pattern, spraying in a pattern
that goes from left to right and then right to left,
with someone scrubbing the stain into the surface
using a medium-bristle brush in a circular motion
just behind the spray. It’s important to scrub
in the stain and not just push it around. An additional
spray pass just behind the scrubbing removes brush
marks. This method ensures good penetration and minimal
marking from either the sprayer or brush.
Additional water can be used to create different concentrations
of stain color. Wetting the concrete before stain
is applied is one way to do this. Following the application
with water from a spray bottle is another way.
Stains applied by paintbrush will penetrate well,
but care must be taken to minimize brush marks, which
are not usually regarded as creative or desirable
application method is used, be sure to carefully mask
surrounding areas to avoid accidental staining. Acid
stains can be difficult, and in some cases impossible,
The increased interest in chemical-stain finishes
is in the direction of more subtle effects. Installers
frequently dilute stains with water to produce less
intense effects. For example, one contractor often
applies the stain the day after the concrete is placed,
starting with a 3% stain dilution (3 parts commercial
stain to 97 parts water by volume), and then adding
more acid to increase the strength to 10%. In this
manner, the contractor can gradually build up color
to meet owner expectations. Second and third colors
can also be added in the same fashion to create color
stained overlay is the best solution for concrete
surfaces that show damage or have been abused during
construction. Commercially available overlay materials
can be integrally colored, textured, and stained to
provide a new range of decorative possibilities. The
overlays have high flexural strength and wear resistance.
As with everything involving stains, however, it’s
wise to create a sample to ensure compatibility of
the overlay cement with the stain and to get owner
approval for the result.
continue – Using dyes and tints