Why Use Stucco For My Home?
Stucco has been used in architectural structures since the Greek and Roman era and during the Renaissance. It spread throughout Europe and gradually became popular in America. Stucco is a finishing plaster composed of sand, lime, water and other ingredients. It is a strong, attractive and damage resistant covering for walls and ceilings. It is an excellent building material for hot areas as it helps to regulate the temperature. It is non-combustible and its surface burning properties include no flame spread and no smoke development.
Currently, there are two distinct types of Stuccoes –
Traditional/Hard Coat Stucco – This is basically cement mixed Stucco. The traditional stucco is durable and able to withstand harsh environments. It is porous and can breathe, so, dries quickly and resists water damage.
Conventionally, lime was used with sand and water. As lime is slightly soluble, the mixture has a self-healing tendency. At present, stuccoes are usually made up of Portland Cement, sand and water resulting in a hard and brittle variety.
To install hard coat stucco, first the substrate is installed followed by a metal lath and then a coat of stucco is applied with a trowel. It is allowed to set and then another coating is applied. Normally, the process involves a scratch coat, a brown coat and a finish coat (may be colored).
Stucco can also be applied on a paper and wire. The coats should be thicker. The first coat (scratch coat) covers the wire. It needs to be scratched as soon as it sets. The second coat (brown coat) gets bonded to this coat and as usual the finish coat is the outermost layer.
Synthetic Stucco – Since 1950s, a number of houses were built using a variety of synthetic materials resembling stucco. Fibers and synthetic acrylics were added to the cement stucco mixture to add strength and flexibility. In general though, the synthetic stuccoes are less heavy and hence, more susceptible to a hard blow. They are a one-coat stucco system unlike the three-coat traditional ones.
The most common one is EIFS or Exterior Insulation & Finish Systems. They are glued or mechanically attached to the substrate and usually composed of three layers. The innermost layer, mostly made up of polystyrene like material, is a foam insulation board. The second layer is a base coating attached to a fiberglass mesh and the final layer is a finish colored coat. It became popular because of its easy installation, low cost and better insulation properties. The only disadvantage is moisture absorption which causes water damage to the building.
A variety of stucco colors/paints are available. Colorants are inorganic pigments which can adapt with the high pH value of cement. They can be either natural like, Ochers and natural earths or artificial, such as man made Iron Oxides. Natural colorants remain unaffected to UV rays and are more pleasant to our eyes. But, the range of shades and the tinting strength is less when compared to manufactured colors. Man made colors, on the other hand, offer a wider range of shades such as dark blues and greens as well as various earthy tones like, yellow, brown and reds. They also possess excellent UV stability due to the presence of inorganic pigments.
How to Paint Stucco the Right Way
As it happens the next generation of EIFS has learned a lot from the last generation
From 1969 to about the year 2000 was the first generation of EIFS where the EIFS foam was installed directly to the substrate of a house. Where the EIFS exterior itself was the weather barrier. Before the year 2000 building codes did not require a secondary moisture barrier. The IRC (International Residential Code) in 2000 required this secondary moisture barrier on all sidings used over wood framed construction. The problem with the EIFS itself being the water barrier is that when any moisture infiltrated the system there was nowhere for it to escape. A properly installed first generation EIFS application that has been maintained has a very good chance of not having any problems. The EIFS can be done right, and the caulk and sealants maintained over the years, and still a window or roof leak can cause major damage over time on a first generation EIFS home. However, you can still have a first generation EIFS home inspected, and after passing the inspection get a warranty on the home through The Moisture Warranty Corporation.
The Next Generation of EIFS has grown and learned from the past along with the entire building industry. The unprecedented testing done has helped many industries, and has had an impact on the building codes. With the addition of a Air/Water barrier to the EIFS process has made significant improvements to the overall performance of EIFS, and is now mandatory on all wood framed construction whether you are using EIFS or not. The next generation of EIFS has been proven to drain water effectively. This overcomes the major issue with first generation EIFS.
The Next Generation of EIFS is a superior material, and out preformed all other exterior wall claddings (including brick, stucco, concrete block, and cementitous fiber board siding) in the Hygrothermal Performance testing by Oak Ridge National Laboratory, which was funded by The US Department of Energy and EIMA. A study by The National Institute of Standards and Technology (NIST) shows that over a 50 year life cycle of a building, the carbon footprint of EIFS is 1770 compared to brick at 8303. We are talking some huge numbers here, as Dryvit, one of the leading manufacturers, boast 'over 2 billion square feet of EIFS applied' you can begin to imagine what a positive impact having such a smaller carbon footprint has had on the environment.
Benefits of The Next Generation of EIFS - Superior Cladding
- Thermal bridging virtually eliminated
- Improved IAQ (Indoor Air Quality)
- Improved overall energy performance of a building
- Helps keep structural members at a consistent temperature, which extends life expectancy
- The constant temperature helps structure member movement and stress from temperature swings that lead to cracking in concrete and stucco walls.
- Dewpoint is eliminated
- Vapor diffusion from condensation is minimized
- Deterioration of batt insulation from condensation is minimized
- Mold growth due to condensation is virtually eliminated
- Rusting of metal fasteners and framing from condensation is minimized
- EIFS has low levels of volatile organic compounds as know as VOC's
- EIFS carbon footprint is 5 times smaller than brick
- EIFS saves money in construction costs
- EIFS is more energy efficient
- ASHRAE (American Association of Heating, Refrigeration, and Air-conditioning Engineers) Standard provides minimum requirements for energy efficient design of buildings - EIFS meets these requirements
- According to ASHRAE 90.1 2001 - 2 inches of EIFS offers the equivalent energy efficiency performance of 8 inches of fiberglass insulation in a wall cavity.
- EIFS puts the continuous insulation on the outside of the building where insulation works best.
- EIFS is in the International Building Code and the International Residential Code
- EIFS provides the continuous insulation (CI) described in ASHRAE 90.1, which is required by the International Energy Conservation Code (IECC)
- EIFS can contribute to LEED certification
- EIFS is the only cladding that has an air-barrier, insulation and aesthetics all in one system, which is installed by a single contractor, with a single warranty
- EIFS has a very low Global Warming impact, where brick has a very high Global Warming Impact
It may not be faster than a speeding bullet and it can not leap tall buildings, but The Next Generation of EIFS is a Super Cladding when compared to the other leading Claddings.