Your building’s exterior won’t last forever. It needs cleaning and upkeep.

And to do that correctly, you need to know what material you’re dealing with. Brick, stone and concrete are easy to tell. But stucco and EIFS are harder to figure out.

It may be hard to tell what surface your building has if you’re not trained in what to recognize. But it’s not that hard if you know what you’re looking for. Here’s how you can tell whether your building’s exterior is EIFS or stucco.

What are EIFS and stucco?

EIFS is an abbreviation for Exterior Insulated Foam Systems. It’s an exterior material that’s made out of insulated foam covered in an impervious outer layer that looks like stucco. Older EIFS installations had problems with water retention, but newer EIFS is built with drainage channels that let water get out.

Stucco is a coating of Portland cement, sand, lime and water. It’s one of the oldest building materials still in use. Usually stucco is applied directly to concrete, but it can also be applied over top of metal mesh.

Figuring out which exterior you have

You can’t usually tell the difference between EIFS and stucco by just looking at it. But EIFS is installed differently than stucco. Stucco should never sound or feel hollow when you tap on it, but EIFS will. That’s because the insulation board is installed away from the wall. It will be rigid, but not as solid-feeling as stucco.

Stucco will feel like a layer over top of something solid. The concrete or metal mesh backing means it’s hard as a rock if you tap it with your knuckles.

You can also tell if you pull out a light fixture or something like that and can see the insulation behind the outer layer. The insulation board will be visible because the outer acrylic layer won’t wrap all the way around under the fixture.

There’s another way to check too. On most EIFS buildings, there’ll be a gap between the cladding and the ground. Reach down to the ground and probe with your fingers. If you catch the edge of the cladding, it’s EIFS, not stucco.

Both surfaces are great exterior finishes. But if you don’t know which one you have, it’s not hard to tell. Taking care of your exteriors is important for the health and longevity of your building.