InterNACHI Stucco/EIFS Inspector key terms

A traditional portland cement plaster system applied in three separate layers: scratch coat, brown coat, and finish coat, typically over metal lath and a water-resistive barrier on framed walls.

A proprietary cementitious plaster system applied in a single thick coat over a prepared substrate, often reinforced with fibers or a specially designed lath, rather than the traditional three layers.

The first layer of portland cement plaster, pressed through the metal lath to key it in place and left with a roughened surface so the next coat can bond mechanically.

The second plaster layer in three-coat stucco, applied over a cured scratch coat and floated to a flat plane that establishes the final thickness and surface for the finish coat.

The final, decorative plaster layer that provides color and texture, applied over a cured brown coat and typically thinner and more cement-rich or acrylic-modified than the base coats.

A galvanized or coated expanded-metal sheet fastened to framing or sheathing to reinforce plaster and provide the mechanical key that holds cement stucco in place.

A perforated metal accessory installed at the base of a stucco wall that supports the plaster, provides a drip edge, and allows moisture behind the cladding to drain outward.

A metal accessory with a raised edge used to terminate stucco at openings, corners, or transitions, forming a straight edge and helping shed water away from the plaster edge.

A deliberate break or accessory installed in stucco to relieve stresses and direct cracking to a planned location, typically required at changes in substrate, large spans, and specific intervals.

A metal or plastic accessory fixed at external corners of a stucco wall to reinforce the edge, provide a straight arris, and resist impact damage to the plaster corner.

The process of maintaining adequate moisture and temperature in cement plaster after application so cement hydrates properly, developing strength and reducing shrinkage cracking.

A sheet or fluid-applied membrane behind stucco that resists water passage while allowing vapor movement, protecting sheathing and framing from moisture that penetrates the cladding.

Exterior Insulation and Finish System: a cladding consisting of an insulated foam board adhered or fastened to a substrate, covered with reinforcing mesh, base coat, and a textured finish coat.

A class of EIFS in which the foam insulation and coatings are intended to keep water out at the face, with no designed cavity or drainage path behind the insulation.

An EIFS assembly that includes a water-resistive barrier, a drained cavity or drainage plane behind the insulation, and weep provisions so water entering the system can escape.

The cementitious or acrylic layer applied over EIFS insulation board, embedding the reinforcing mesh and providing the substrate to which the finish coat bonds.

A woven glass-fiber fabric embedded in EIFS base coat to add tensile strength, resist cracking, and distribute impact and thermal stresses across the lamina.

The combined base coat and finish coat layers of an EIFS that form the protective skin over the insulation board and carry the reinforcing mesh.

Rigid foam plastic panels, commonly expanded or extruded polystyrene, used in EIFS to provide thermal resistance and form the substrate for the base coat and mesh.

The bonding material, often a cementitious or acrylic-based compound, used to attach EIFS insulation board to the substrate, sometimes applied in ribbons or notched patterns.

A screw and washer assembly used to secure EIFS insulation board or attachments to framing when adhesive alone is not used or when codes require supplemental attachment.

The structural or sheathing surface to which stucco or EIFS is applied, such as wood sheathing, gypsum board, masonry, or concrete, whose condition and flatness affect performance.

The panel material, such as oriented strand board, plywood, or gypsum, fastened over framing to enclose the wall and receive the water-resistive barrier and cladding.

The surface within a wall assembly, usually the water-resistive barrier, over which water that gets behind the cladding can flow downward to flashing and out of the wall.

Waterproof material installed at wall openings, roof-wall intersections, and other transitions to direct water away from the wall assembly and prevent entry behind the cladding.

A flashing piece at the bottom of a roof-to-wall intersection that turns water out and away from the wall face rather than letting it run down behind the stucco or EIFS.

Flashing installed above a window, door, or other wall penetration to shed water onto the cladding face or into a drainage path, typically with end dams.

Flashing at the bottom of a window or door opening that collects water and directs it to the exterior, often integrated with pan flashing and the water-resistive barrier.

A continuous flashing pan under a window opening, with upturned ends and a sloped sill, that collects and drains water that passes the window unit.

The unintended entry of water or water vapor into a wall assembly through defects, gaps, or failures in cladding, flashing, sealant, or penetration detailing.

A whitish, powdery deposit of soluble salts carried to the surface of stucco or masonry by water and left behind as the water evaporates, often indicating moisture movement.

A break or fissure in stucco or EIFS finish, ranging from fine hairline cracks to wide structural separations, which can admit water and signal substrate or material problems.

Separation of one stucco or EIFS layer from another or from the substrate, often appearing as hollow-sounding areas, blisters, or loose material that can detach.

The bond between a coating or plaster layer and the surface beneath it; poor adhesion allows layers to separate and is often tested by pulling or probing.

The detail where stucco or EIFS ends near the ground; it must maintain clearance above grade and use a weep screed so water can drain and rising damp is limited.

A metal accessory with a projecting lip that sheds water off the bottom edge of stucco, used at locations other than the base of a wall where a drip is needed.

A flexible joint material applied around pipes, fixtures, and other items passing through stucco or EIFS to keep water out at the opening.

Inspection by removing or opening small areas of cladding, such as cutting an EIFS probe, to directly observe hidden layers, moisture, and flashing conditions.

An instrument used during inspection to detect elevated moisture in stucco, EIFS, sheathing, or framing, often used with probes or pinless scanning to locate suspect areas.