Knowledge
of the complex chemistry of concrete helps to ensure
the successful completion of decorative concrete projects.
Contractors should:
Notify owners and clients
in advance of the variable nature of color in concrete.
Joe Nasvik, Concrete Construction magazine, Addison,
Ill., advises that contractors explain to owners and
designers during pre-project meetings how efflorescence
can shift color hues; and
Develop different mixtures
to compensate for hot- and cold-weather concreting.
In hot, windy conditions, surface crusting will adversely
affect stamping projects, and it may be necessary
to accelerate hardening. The Stamp Store's Bannister
encourages anyone entering the decorative concrete
field to consider first being certified as a flatwork
finisher.
EXISTING
CONCRETE ENHANCED
When decorating existing concrete with overlays made
from polymer-modified cement mortar, the ability to
identify causes of problems in previously placed slabs
may be the determining factor in whether to take on
a project. As versatile as spray-texture decorative
concrete systems are, DCC board member Frank Lewis suggests
that a contractor answer this question first: "Is
this particular piece of concrete something I want to
put an overlay on?" Lewis is Director of New Product
Development and Traing for Sundeck Products, Inc., Arlington,
Tex.
If concrete surfaces are cracked
or spalled, the conditions that caused these distress
symptoms have to be corrected. This may be difficult
because contractors bidding on an overlay for an existing
slab may not have much information about subbase conditions
or concrete quality. But if they can't identify causes
of existing problems -and correct them- the overlay
is likely to fail.
After the stencil is removed,
the grout tine is visible
