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Stucco

EIFS

> Features/ Benefits

EIFS
EIFS (pronounced eefs) is an acronym for Exterior Insulation Finish Systems. The basic process involves attaching insulation boards to various substrates like sheathing or concrete block, then troweling on a base coat which is reinforced with a mesh fabric. The final process involves troweling on a decorative finish color top coat which is floated to assimilate many varied textures.

Click here for Ten Reasons why EIFS should be your #1 Choice of Cladding

features and Benefits
	Environment	Energy Efficiency	Water Resistance	Fire Resistance

	Building Code	Durability	Appearance

• Polystyrene uses only .002% of the world's oil supply in its production. Repeat: That is 2/1000th of a barrel of oil!
• EPS uses 30% less energy to produce than paper does.
• EPS is 90-98% air.
• The energy used in the EPS production process is recovered many times over by the energy saved in the buildings in which it is installed. One kg (2.205 lbs.) of EPS saves at least 400 liters (105.6 gallons) of oil over 50 years. In English units that is one pound of EPS saves at least 48 gallons of oil over 50 years.
• The blowing agent used in creating EPS is not harmful to the environment.
• There are no CFC's or HCFC's in EPS.
• EPS does not experience any off-gassing which may be harmful to interior air quality.
• EPS does not contain formaldehyde.
• EPS does not support common mold or fungi.
• The energy EPS incineration creates is approx. 16,000 BTU's/ pound. This is twice the value of coal.
• Technology now exists to reduce discarded polystyrene by a densification process that effectively reduces its volume by 95%.
• EPS represents only 0.6% of the volume in our landfills.

• New research comparing both overall insulating ability and moisture resistance show EIFS with 4-inch foam insulation "outperformed" walls of brick, stucco, concrete block and cementious fiber board in moisture handling with "superior thermal performance."
• The proprietary water-resistive membrane's used on the new EIFS drainage systems are impervious not only to water, but are superior air barriers as well.
• According to the National Institute of Standards and Technology an effective air barrier can reduce buildings annual energy consumption for heating and cooling by up to 40%.
• EPS that is attached over the new air and water-resistive barriers in the new drainage systems is attached by adhesive. No fasteners are used that might puncture the membrane. This provides a 100% monolithic barrier that cannot be breached by water or air penetration.
• EIFS solves thermal bridging created by conventional framing techniques. Insulation is where it belongs, placed to the exterior. This is a little like putting a thermal blanket around the building which provides greater energy efficiency, comfort and cost savings.
• The R-value of EPS is a constant 3.85/ inch. EPS does not experience thermal drift which minimizes its thermal effectiveness.

• Using vertical ribbons of adhesive in an EIFS with drainage configuration, provides a drainage path for moisture and an airspace that contributes positively to hygrothermal performance.
• Third party testing shows that a drainage space as thin as a dime drains moisture quickly and well.
• Moisture that may breach the EIFS is insignificant because of the redundant nature of the monolithic liquid applied water-resistive barrier.


	• EIFS does not add or detract from a fire rating. EIFS is perhaps the most tested wall cladding product in terms of its exposure to fire, ignition sources and combustibility.


	• EIFS has been recognized as part of the 2009 International Building Codes.

• EIFS has been used successfully in the Twin Cities for over 30 years. Here are some examples of its longevity:
1978 - Dakota Ridge Best Western, formerly known as Yankee Square Inn, Eagan, MN
1978 - The Arne Chiropractic Clinic, Minnetonka, MN
1980 - Marriott Minnetonka, West
1985 - Macy's formely Dayton's, Southdale Mall
1985 - The Marriott Minnetonka
1986 - The Toro Manufacturing Plant, Bloomington, MN • Adding reinforcing mesh or high impact reinforcing mesh increases EIFS impact resistance.
• Finish choices are better than ever:
o Darker colors are achievable with pigments that remain UV stable.
o Many finishes now come with Dirt Pick-up Resistance (DPR) technology.
o Finishes are available that are more moisture resistant.


	• New look finishes now include, luminescent micas, fine aggregates, limestone, metallics, simulated brick and stains that emulate old world finishes. • EIFS has always been identified by the architectural community for its ease in creating shapes, bands and other architectural features effortlessly.

There are technically four types of EIFS

(1) Class PB or Polymer Based EIFS:

Uses expanded polystyrene insulation board which is adhered to the substrate with proprietary polymer based adhesive that is applied with a notched trowel to the back of the insulation board. In most cases the adhesive that is used in this process is the same material that is used for the base coat and may or may not include portland cement in its composition. After the board has been allowed to set, the surface of the insulation board is often rasped to flatten out high spots and break the surface for a better key of the base coat. The base coat is then troweled onto the surface and a reinforcing mesh is encapsulated by embedding it with a trowel into the base coat. In some instances it is necessary to add more base coat to completely encapsulate the mesh. This process is then followed with an acrylic decorative finish color top coat, floated to the desired texture. Typical thermal values of expanded polystyrene foam board are R3.65/inch. Typically wall thicknesses of these systems are installed from 1" to 4". Larger thicknesses are often used to create the look of heavier decorative features, such as quoins, bands, classic entablature and other decorative shapes.

(2) EIFS with Drainage:

In most cases is similar to that of PB EIFS with the exception that a liquid applied water-resistive barrier is installed over the substrate to provide a level of redundancy for moisture protection. These liquid membranes are troweled, roller, or spray applied, generally over a substrate of glass fiber faced gypsum sheathing, oriented strand board or plywood, depending upon the manufacturer's requirements. Combined with compatible reinforcing fabrics and membranes, penetrations and joints between the sheathing boards are treated to help prevent moisture from breaching the assembly and getting into the cavity or framing of the building. The expanded polystyrene insulation board is adhered with a proprietary adhesive with a notched trowel. The adhesive is oriented in a vertical direction on the back of the insulation board, to provide a medium for the drainage of moisture between the liquid applied membrane and the insulation board. After the board has been allowed to set, the surface of the insulation board is often rasped to flatten out high spots and break the surface for a better key of the base coat. The base coat is then troweled onto the surface and a reinforcing mesh is encapsulated by embedding it with the trowel into the base coat. This process is then followed with an acrylic decorative finish color top coat floated to the desired texture.

There still exist more rudimentary and complex forms of these types of systems, which include mechanically attaching housewraps or building paper, drainage mediums of tangled plastic netting, furring, channeled and compartmented insulation board. While many manufacturers still carry these products, they have fallen out of favor in lieu of the newer more user friendly and advanced technology.

(3) Class PM or Polymer Modified EIFS:

Uses planed or sanded extruded polystyrene insulation which is mechanically attached over a water-resistive barrier and substrate with screws and plastic washers or discs. The reinforcing mesh is generally attached using the same fasteners as are used in attaching the insulation board. The base coat is mixed with the addition of cement, sand, water and a liquid polymer to make a coating that is applied 1/4" to 3/8" thick. This is followed by a texture able acrylic decorative finish color top coat. Because of its thickness, coefficient of expansion and contraction and its affinity to similar stucco compositions, PM systems require mechanical control joints to provide stress relief from panel to panel. Typical thermal values are approximately R5/ inch of extruded polystyrene foam board. Limitation to this product's use is higher cost of materials while being much more labor and skill intensive than the PB system. Competitive in the 1980's with the more popular PB systems, PM systems are not used to any great extent today, although many manufacturers still carry them as part of their product line.

(4) Class PI EIFS:

PI in this reference refers to Polyisocyanurate Insulation boards. PI boards generally have a higher density than extruded or expanded polystyrene insulation board, with a higher thermal value of approximately R7/ inch. They are distinct in that the core is yellow in color and a fiberglass facer is installed over the surface of the board. Because of these physical characteristics, PI board is typically installed mechanically with screws and polypropylene discs over substrates generally of sheathing board. Because of the fiberglass facer, rasping of the board is prohibited. Like PB systems however, a proprietary polymer base coat is applied over the surface of the insulation board and a fiberglass reinforcing mesh is embedded into it. Finish is applied in a similar manner to PB EIFS. PI systems have had a larger following in the residential market because of their simplicity of installation. Occasionally they are used in a commercial setting as a substrate for darker pigmented finishes. This is because the in-service temperature of the PI board exceeds that of expanded polystyrene. Like PM systems however, their use have diminished over the years in favor of products that have been developed for EIFS with drainage.