Robert Thomas is a nationally recognized EIFS consultant, based in Jacksonville, Fla.
He was the manager of technical services for a major EIFS producer, is the
author of several books about EIFS and chairs the ASTM committee on EIFS.
There are lots of small details and design features about EIFS that can help create a better-completed EIFS project. This month’s column is a list of many known-and not-so-well-known-design features that you should be aware of.
In the May column “Keep it Dry,” I talked about issues to be dealt with when using EIFS that incorporate a water resistive barrier. WRBs are most often used in the increasingly common EIFS with drainage. Most of the discussion in that article was about various design aspects.
In EIFS, water resistive barriers are a layer between the EIFS substrate and the EIFS insulation. They are most commonly used in EIFS with drainage wall assemblies. They are an additional layer within the wall cladding system and present some unique issues that are worth knowing about. Here are some of the issues.
Because EIFS are a jointless type of wall cladding that can be installed over a huge wall area without joints at all, it’s clear that the only way for water to get behind the EIFS is somewhere at the edge of the EIFS. This penetration is most often at windows, openings and flashings.
Expanded polystyrene insulation and polyisocyanurate foam polyiso are the two main insulation types used in EIFS in North America. Overseas, many other types of insulation are used to make EIFS, such a mineral wool and “glass foam.”
I often get calls from people wanting to “beef up” the performance of their EIFS walls. There are some things you can do to improve performance and this month’s column has a potpourri of strategies for common problems.
There is work underway to develop a standardized protocol for inspecting EIFS as it is being installed. This work is being done by the ASTM technical society.
When I do technical seminars about EIFS, one of
the most frequent questions is, “Should I use adhesives or mechanical fasteners
(screws plus washers), or even both, to attach the foam insulation to the
wall?” The answer depends on a number of factors, and sometimes you have no
choice about which to use.
When
EIFS with drainage is used, the details at the termination of the EIFS are
different from traditional EIFS. This is especially true at the bottom edge of
an EIFS wall.