| Final grade | Soffit
and fascia | Electrical
and gas laterals | House
wrap | Masonry |
| Siding | Exterior
concrete | Exterior
paint | Foundation
Stucco has been used in architecture for thousands
of years. It is durable, relative maintenance free,
and offers unlimited design possibilities Traditional
stucco is a combination of cement, lime, sand and
water. It is troweled by hand to the exterior walls.
Traditionally stucco has been very popular in the
southwest part of the country. Today stucco has become
one of the most popular building covers in the past
Today there are
many different types of stucco systems. Traditional
stucco is still popular but synthetic stucco is gaining
in popularity. The main types of stucco used are:
Traditional, 2 coat synthetic, and EIFS (pronounced
"ee-fus") which stand for Exterior insulated
Traditional stucco is made of Cement lime, sand and
water. It is still frequently used in the Southwestern
U.S. Before stucco is applied, a building paper is
attached to the exterior followed by wire mesh (chicken
wire). Traditional stucco is applied by trowel in
3 separate coats. The building paper repels moisture,
as water will pass through traditional stucco. The
first coat is called a brown coat and is applied thick
enough to cover the wire lath, usually about ¼"
thick. the next coat is called a scratch coat because
it is troweled on to a thickness of about 1/8"
and then scratched with a rake like tool. The grooves
created by the tool help the top coat to adhere to
the scratch coat. The stucco is then painted to the
The two-coat synthetic stucco is prepared the same
way as traditional stucco with a felt paper and chicken
wire base. The brown coat is applied over the chicken
wire the same as traditional stucco. The second coat
or finish coat is then applied over the base coat.
The difference is that the finish coat is made up
partially of synthetics and fibers which make the
stucco flexible and less likely to crack in seasonal
climates. The color pigment is contained in the finish
coat so that after it is applied no paint is required.
EIFS systems have been very popular for the past 10-15
years, but have a troubled past. Many EIFS systems
have failed in wet, damp climates, due to water penetration
under the insulation board.
EIFS system start by gluing insulation board on the
exterior of the house. Insulation serves the purpose
of providing energy savings for the home and a waterproof
envelope surface to apply the stucco. Two top coats
are applied over the insulation similar to the two-coat
synthetic stucco system. The EIFS system relies on
the insulation board to keep out 100% of the moisture.
In Dry areas or where the EIFS system is sealed well
enough to keep 100% of the moisture from penetrating
the enclosure, the system works fine. The problems
is when water gets behind the insulation (through
cracks, poor installation, or around opening such
as doors and windows) the moisture has no means of
escape, and wood rot is the result. Investigations
found that some homes where moisture penetrated had
begin to rot in less 2-3 years.
If the system is totally waterproof the system works
well, however, it is becoming more evident that due
to expansions and contractions of building materials
that even a system that is water tight today may develop
infiltration problems over time.
The real problem is that water will get behind almost
any exterior system, so instead of trying to make
a waterproof system the exterior surface should be
designed to "breath" allowing trapped moisture
In the past several years there has been legal action
brought against the major manufacturers of EIFS systems
to address its short comings and to get compensation
for homeowners with failed stucco. Because of the
failing of the system and the legal action, most of
the major manufacturers have now developed a "drainable"
or "water managed" system that addresses
It should also be noted that homes constructed with
concrete block or insulated concrete block system
didn't suffer with traditional EIFS systems because
there is no wood behind the insulation to rot.