Exterior Insulation and Finish System (EIFS) is an exterior wall cladding that utilizes rigid insulation boards on the exterior of the wall sheathing with a plaster appearance exterior skin. EIFS in its current basic form was developed in West Germany in the 1960s and introduced in the United States in 1969 by Dryvit. The Dryvit system consisted of expanded polystyrene (bead board) attached adhesively to the sheathing and covered with a lamina composed of a modified cement base coat with woven glass fiber reinforcement and a textured colored finish coat. Over the years, variations of this system have been developed.
Problems observed with in-service EIFS installations are primarily related to moisture intrusion. EIFS provides protection against moisture infiltration at the base coat; however, moisture migration through openings for windows, flashings and other items, or holes and cracks in the EIFS itself, have allowed leakage to occur on EIFS clad buildings. With barrier EIFS installations, or where weather barriers and flashing are improperly installed in conjunction with wall drainage EIFS installations, moisture has entered the wall system at these locations and caused damage to the wall sheathing and framing. The extent of these occurrences on wood frame structures has led to class action lawsuits.
Do not use at temperatures below +5°C.
Wall to be treated must be absolutely clean, free of dust and dry to the touch. Remove loose or powdering elements with a hard broom or wire brush. Then rinse or hose down with water and let dry completely. Do not use soap or synthetic cleansers. Residue thereof is hard to remove, thus reducing water repellent action and penetrating power of Bison Buitenmuur Coating. Fill deteriorated mortar joints or cracks in wall with cement mortar. Cracks no wider than 0,3 mm will be covered up by Bison Exterior Wall Coating.
Brush or air pressure atomizer.
Do not dilute coating.
1 - 3 m˛/l, treated twice, strongly depending on nature of surface. Test treat about 1 m˛ of intended surface to get a good indication.
Apply coating in two generous layers with a brush or air pressure atomizer. Apply second layer while first one has penetrated into surface but has not yet dried completely (wet on wet). Apply both layers until surface has been completely saturated. Wall should, so to speak, be dripping with Exterior Wall Coating. One layer, no matter how generously applied, is not sufficient. Do not treat large surfaces all at once.
Apply Bison Exterior Wall Coating from top to bottom. Surfaces not to be treated, such as window frames, door posts and windows, should be carefully taped off or covered. When painting over woodwork, stains caused by Bison Exterior Wall Coating will affect the paint's quality and adhesiveness. Stains on windows are not removable. Prevent Bison Exterior Wall Coating from coming into contact with plants, bushes or grass by covering them up. Do not use Bison Exterior Wall Coating in case of rain or fog, when rain is expected or at a relatively high humidity level. Recently cast concrete needs 3 to 4 weeks to harden before being fit to be treated with Bison Exterior Wall Coating, otherwise coating cannot penetrate sufficiently.
A freshly treated wall will show a pearl-effect: rain pearls down the wall. After some time, this effect will subside. However, wall will continue to be rain- and moisture resistant. To find out if surface is suitable for impregnation, perform a test with water or, even better, try impregnating a small area with Bison Exterior Wall Coating.
Remove fresh stains immediately with water. Dried residue can only be removed mechanically.