Yes. As with all wall cladding, flashing is an important component required by building codes. At points where water can enter the wall it should be directed to the exterior face of the cladding with flashing. Transition areas such as decks or roof/wall intersections are typical areas where flashing must be installed. Openings for windows and similar through-wall penetrations require jamb, head, and sill flashing to direct water to the exterior face of the cladding.
Note: Complete moisture protection requires rough opening protection and the integration of air seals, sealants, and flashings.
As with all claddings, the most common water entry points in a wall are through or around windows, transitions from roof to walls, and transition from wall claddings to doors and chimneys. This coupled with improperly installed or missing flashing and sealants, can allow water to penetrate behind EIFS, or any other cladding, and into the wall cavity, where it can potentially cause moisture damage.
Some of these problems are inherent in the components themselves and other result from incorrect installation practices.
No. Moisture intrusion is a potential threat to durability of materials in wall construction, regardless of cladding type. Moisture intrusion should be avoided by following sound design and construction practices mandated by building codes.
Yes, but depending on the manufacturer and the product selected, the EIFS vapor permeability may vary. When requested, the EIFS manufacturers can perform a Water Vapor Transmission Test for specific walls to evaluate the tendency for condensation to occur.
EIFS with drainage is conventional EIFS installed over a water-resistive barrier, with provisions for discharging of incidental water that may enter behind the insulation board. In the event of a breach of the EIFS, the drainage path for moisture exists behind the EIFS to drain water to the exterior.
Note: EIFS with drainage is not meant to accommodate rainwater that penetrates through other components of construction. Flashing is required where rainwater may penetrate other components and at the interface of different components.
EIFS manufacturers recommend the use of water-resistive barriers over moisture sensitive substrates to provide additional protection in the event of a component failure. Local building codes will stipulate whether this is a requirement or not.