EIFSFACTS.ORG
The Real Facts About EIFS
- Can Barrier EIFS be Maintained? -
As discussed in the EIMA Lies and Contradictions page, barrier EIFS has gone from initially being touted as "maintanence free" to "virtually maintenance free" to "low maintenance" to "requiring minimal maitenance" to "easy to maintain compared with other types of siding".
EIMA says "Like any other kind of home cladding, your EIFS requires some normal minimal maintenance. In addition, you should inspect the sealant around your windows and other penetrations each year as you go about your normal yard work. Cracked or dried-out sealant should be replaced."
EIMA, "I've Heard About Problems With EIFS. I've Got an EIFS on my Home. Should I be Concerned? - Questions and Answers from EIMA", 1997
So, EIMA's premise is that a face-sealed barrier system, such as barrier-EIFS, can be built water-tight and kept that way through a reasonable maitenance program. Unfortunatly, many building experts say that not only is this concept not reasonable, it is simply impossible:
"U.S. Gypsum believes that the relative quality of construction of EIFS claddings in New Hanover County is representative of other markets in the U.S. Factors that influence the integrity of EIFS walls include design, workmanship, window quality, sealant performance and long-term maintenance of sealants. Additionally, local climatic conditions and vapor-control practices will affect wall-drying potential. As such, U.S. Gypsum [a manufacturer of EIFS] has concluded that barrier-EIFS wall construction and maintenance is impractical and EIFS performance is unreliable."
U.S. Gypsum Company, "USG Press Room: Summary of EIFS Research", 1996
The face-seal approach attempts attempts to eliminate all openings in the wall through which water can pass. However, the materials used to seal all these openings are exposed to extremes of weather and the movements of the building. Even if the problems of the jobsite inaccuracies and poor workmanship can be overcome and a perfect seal can be achieved, the in-service weather conditions will eventually cause the deterioration of and failure of these seals, creating openings in the wall through which water can pass. Unforunately, these openings can be extremely tiny and difficult to identify, so that even an extensive maintanence program may not keep the building free of openings."
Rousseau, J. and Quirouette, R.L, "Water Leakage Through Building Facades, ASTM STP 1314", ASTM, 1998
"It is not conceivable that a building designer can prevent the exterior surface of a wall from getting wet nor that he can guarantee that no openings will develop to permit the passage of water. It has, however, been shown that through-wall pentration of rain can be prevented by incorporating an air chamber into the joint or wall where the air pressure is always equalt to that on the outside [brick, masonry, siding, etc.]. In essence, the outer layer is then an 'open rain screen' that prevents wetting of the actual wall or air barrier of the building. The success of the traditional walls ... is explained by this principle. ... It should be empahsized that that the open rain screen principle of rain penetration control can be employed for any situation where rain penetration of walls and wall components can occur, especially at joints between prefabricated components."
Garden, G. K., Canadian Building Digest, Volume 40, "Rain Penetration and its Control", CBD, 1963
"Openings that permit the passage of water are quite numerous on the face of a building in the form of pores, cracks, poorly bonded interfaces and joints between elements or materials. Very small pores and cracks can be covered with impermiable or semi-impermiable coatings or treated with surface waterproofing compounds, but these treatments are less likely to be effective for larger pores or cracks. Joints between elements or materials can be sealed with gaskets or sealants. If they are located where they can be wetted by rain, however, the seal must be perfect, and this is difficult to achieve because of fabrication or job site inaccuracies.Even more difficult is the maintenance of a perfect joint over a reasonable period of time, because of the aging of the sealant and because differential movements between the elements constantly flex and stress the joint material. Skill and new sealing materials can be employed, but it is seldom possible to guarantee that no openings will develop to permit the passage of water."
Garden, G. K., Canadian Building Digest, Volume 40, "Rain Penetration and its Control", CBD, 1963
"When the sealants of a face-sealed cladding fail, the walls lose their water-tightness and air-tightness; this translates into severe disability of the envelope in performing its intended functions. As a consequence, face sealed walls require frequent and costly maintenance during the life of the building. The approach has little to recommend it and is considered impracticle for buildings in Canada."
National Building Code of Canada, Part 5, 1990 Edition