Standard EIFS installations involve adhering and/or fastening the rigid insulation board directly to a substrate. Recently, EIFS with drainage systems (water management systems) have been designed and made available by EIFS manufacturers. Although the drainage systems differ somewhat in design from manufacturer to manufacturer, the principal of this system is to allow water that may infiltrate behind the EIFS to channel safely out of the system. The sheathing is protected by a water resistant material (in many cases this is 15# felt paper) and the channel is created by grooves in the foam or more typically, use of Tyvek Stucco Wrap. Because of the channel design, the drainage system often uses mechanical fasteners in lieu of adhesive.

There is a lot of controversy about whether to use a drainage system or a standard barrier system. Our position on this matter is as follows:

  • If the code requirements or specifications call for a drainage system, then definitely install it that way.
  • A drainage system will give added protection against water damage, however, it is not a "fail‑safe" system and there is added cost in labor and materials.
  • If a standard barrier EIFS is installed and maintained properly, it will not leak. 

Our position on this issue certainly doesn't solve the controversy. We stand behind our products and our approved and certified applicators. If you need an EIFS with a drainage system, we have an excellent system. If you need barrier class PB EIFS, direct applied class DA EIFS or a hard coat class PM EIFS, we continue to have the best products and systems available there too.