The short answer
Traditional three-coat stucco is cement plaster (scratch, brown, and finish coats) over lath and a weather-resistive barrier. EIFS, the synthetic stucco system, is foam insulation board with a mesh base coat and a flexible synthetic finish. Three-coat is hard and sounds solid; EIFS is lighter and sounds hollow. They repair differently, so the first job is identifying which one is on your wall.
Traditional three-coat stucco
Three-coat stucco is a cement-based system: a scratch coat and brown coat troweled over metal lath, then a finish coat, all over a drainable weather-resistive barrier. It is hard, durable, and the default exterior assembly we recommend for new and replacement work in our climate because it stands up to Pacific Northwest rain. When it fails, it is almost always the barrier or flashing behind it, not the cement itself.
EIFS, the synthetic stucco system
EIFS stands for Exterior Insulation and Finish System. Instead of cement over lath, it is a foam insulation board adhered or fastened to the wall, a base coat embedded with reinforcing mesh, and a flexible acrylic finish coat on top. It adds insulation value and a crisp, uniform look, and it is common on some commercial buildings and mid-century and newer residential builds. Because there is foam behind the finish, it is lighter and sounds hollow when tapped.
How to tell which one you have
Tap the wall. Three-coat stucco is hard and solid; EIFS sounds hollow and gives slightly. Look at the edges around windows and at trim, where the two systems terminate differently. If it still is not obvious, we confirm it during the walkthrough, because the repair approach depends entirely on getting this right.
Why the difference matters for repair
A cement patch belongs on three-coat stucco, not on EIFS, and vice versa. EIFS repair means matching the base coat, mesh, and synthetic finish and, critically, getting the flashing and sealant details right, because early barrier-style EIFS with no drainage path is where the system earned its bad reputation. Modern drainable EIFS performs well when the details are correct. Either way, most EIFS and stucco failures in our climate are water-related and start at a detail, which is covered in our guide on why stucco cracks.
We install and repair both
Stucco Repair Services works on traditional three-coat stucco and EIFS across Everett, Seattle, and the Eastside. See our stucco repair service, and if you are weighing a fix, the repair vs. replace and cost guides.
EIFS vs. three-coat, answered.
What is the EIFS stucco system?
EIFS (Exterior Insulation and Finish System), sometimes called synthetic stucco, is a multi-layer cladding: a foam insulation board, a base coat with reinforcing mesh, and a flexible synthetic finish coat. It looks like stucco but is built and repaired very differently from traditional cement stucco.
How do I know if I have EIFS or real stucco?
Tap the wall. Traditional three-coat stucco is hard and sounds solid over cement and lath. EIFS sounds hollow and feels slightly soft because there is foam behind the finish. Edges at windows and trim also look different. When it is not obvious, we confirm it during the walkthrough before scoping any repair.
Is EIFS bad?
EIFS is not inherently bad, but early barrier-style EIFS with no drainage path earned a poor reputation because water that got in had no way out. Modern drainable EIFS performs well when installed correctly. The problems are almost always at the details: flashing, sealant joints, and terminations, not the field of the wall.
Can you repair both EIFS and three-coat stucco?
Yes. Stucco Repair Services installs and repairs both traditional three-coat stucco and EIFS. The two systems fail and repair differently, so identifying which one you have is the first step in any accurate repair scope.