Exterior Insulation and Finish Systems (EIFS) seemed like a great idea, but something didn’t work out as well as was expected. “It’s complicated,” says ASHI Reporter. There isn’t just one EIFS system, and there’s no single way to install it. Likewise, there are numerous methods for evaluating the integrity of this common exterior wall cladding.
EIFS layering can differ from one home builder to the next.
How Synthetic Stucco Differs From the Real Thing
Originating in Europe and making its way to the U.S. in the 1960s, synthetic stucco made real headway in the 1990s. This system of cladding was originally used only on masonry walls. But in time, its use broadened wood frame construction as well.
Because it’s an inexpensive system, builders, and home improvement companies switched to synthetic because of its impressive ability to insulate and its “architectural flexibility,” says ASHI. But whether it’s less expensive than real stucco depends on your contractor. Home Advisor asserts that EIFS is more expensive than the real thing.
Most synthetic stucco installations consist of sheathing such as plywood, a water-resistant barrier, insulating foam board, a base coat of the stucco material, and then a finish coat of acrylic on top. But the layering order, as well as the types of layers, can vary. Authentic stucco has no underlying insulation but does have felt paper, wire mesh, a base coat of Portland cement, or metal lath and a cement layer on top.
Where EIFS Went Wrong
Two of the biggest attractors of EIFS were its insulating power and its flexibility. Real stucco doesn’t insulate as well as EIFS. And installers could apply an EIFS system over intricate details, unlike authentic stucco. It’s a watertight system, which sounds like a good idea. But it’s only a good idea in a perfect world.
Problems started creeping up in the southeast but ultimately spread around the country. Water infiltration caused the wood framework to rot, says ASHI. What’s worse is that the damage didn’t take a decade or more to emerge, sometimes it happened within the first year or two.
EIFS keeps water out, but it also holds water in. “It’s a little bit like putting a building in a plastic bag,” says ASHI. EIFS is not breathable. And anywhere the watertight seal was compromised, such as around windows and doors or where a light fixture was installed, water had an entry point. But unfortunately, it didn’t have a way back out. Real stucco absorbs water and lets it drain away.
ASHI identifies certainly “problem areas” that inspectors should always investigate. Those include the windows and doors already mentioned, every penetration through the stucco (plumbing, electrical, etc.), along roof flashing, fancy architectural details and everywhere EIFS runs below grade.
The simplest way to know whether you’re dealing with EIFS and not stucco is the knock test. EIFS sounds more hollow and it’s got a softer, almost flexible feel. Conversely, stucco produces a hard tap sound and has a rigid feel that doesn’t “give.”
Water infiltration with EIFS can clue you in on substantial and costly structural problems. When reported, customers should be advised to hire a pro in EIFS installation and repair. That’s the safest way to gauge the scope of damage and get an accurate quote for restoring the home.
A home inspector’s work is never done, and thankfully Home Inspection Report is here to make it simpler. You can take clear images of EIFS defects or any other issues, and add them to the report in a snap. Download our home inspection app for Android and see why so many inspectors rely on this technology every day.