InterNACHI Stucco/EIFS Inspector flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Scratch coat thickness

The first coat of three-coat portland cement stucco, nominally about 3/8 inch thick, applied over lath or masonry and scored to provide a key for the brown coat.

Brown coat purpose

The second coat of three-coat stucco, nominally 3/8 inch thick, applied over the cured scratch coat to build thickness, provide a level plane, and receive the finish coat.

Weep screed function

A metal base screed with weep holes installed at the bottom of stucco walls to allow incidental water to drain out from behind the stucco and to provide a straight termination.

Metal lath furring

Self-furred lath or furring fasteners hold metal lath at least 1/4 inch off the sheathing so stucco can key through the openings and embed the lath completely.

Control joint spacing

Keyed or surface control joints in stucco are typically spaced about 10 to 15 feet in each direction and placed at substrate changes, corners, and penetrations to control cracking.

Casing bead use

A metal accessory with a flange used to terminate stucco at openings and penetrations, providing a straight edge and a joint line for sealant without crushing the lath furring.

Water-resistive barrier laps

The WRB behind stucco is lapped shingle-fashion so upper courses overlap lower courses, keeping water flowing outward and downward rather than behind the barrier.

Barrier EIFS definition

An EIFS assembly with no drainage cavity that relies on the sealed face lamina to prevent water entry; a breach in the finish or sealant admits water behind the insulation.

Drainage EIFS components

A water-managed EIFS with a WRB, a drainage plane, grooved or notched insulation forming a cavity, and a base drainage track or weep detail to discharge water.

EIFS lamina definition

The outer EIFS layers consisting of reinforced base coat and textured finish coat over EPS insulation; the lamina provides weather resistance and appearance but is not structural.

Mesh embedment

Alkali-resistant fiberglass mesh is embedded in the base coat with specified laps, typically at least 2.5 inches, and backwrapped at terminations to reinforce the lamina.

EPS board joints

Insulation board joints in EIFS must be tight and offset from substrate joints; gaps wider than about 1/16 inch are filled to keep the lamina flat and continuous.

Backwrapping EIFS

Folding the reinforcing mesh around the edge of the insulation at terminations and openings so the base coat wraps the edge, protecting the lamina from water and impact.

Sealant joint limitation

Sealant at EIFS penetrations and windows is a secondary seal; it does not replace flashing, and failed sealant is a common water entry path in barrier systems.

Four water entry paths

Common stucco and EIFS water entry points are penetrations, terminations, horizontal ledges, and cracks or failed sealant, each requiring a flashing or drainage remedy.

Wood moisture threshold

Elevated sheathing moisture in stucco or EIFS walls is often flagged at roughly 16 to 20 percent wood moisture content, confirmed by probing or destructive testing.

Kick-out flashing

A flashing at the bottom of a roof-to-wall intersection that diverts roof water away from the wall; it must extend above the roof and project past the wall face.

Sill pan flashing

Flashing installed under a window or door sill, with a sloped sill and back dam, to collect and drain water that enters at the opening instead of relying on sealant.

Weep screed clearance

The weep screed should sit at least 4 inches above grade or 2 inches above paved surfaces so the drainage path stays open and the stucco base does not stay wet.

Diagonal crack significance

Diagonal cracks radiating from the corners of openings suggest stress concentration or movement and warrant further evaluation, unlike fine random shrinkage map cracking.

Efflorescence meaning

A white salt deposit on stucco or masonry that indicates water has moved through the assembly and evaporated at the surface; it is evidence of moisture, not the cause.

Shingle-fashion flashing

The rule that upper layers overlap lower layers so water flows down and out; the WRB laps over the top flange of flashing and head flashing laps jamb flashing.

Window flashing sequence

At an opening, install sill flashing first, then jamb flashing, then head flashing with a drip edge and end dams so water is directed out and over the layers below.

Deck ledger flashing

A Z-flashing or spacer at a deck ledger keeps the ledger off the stucco and directs water away, preventing trapped moisture at the wall-to-deck connection.

Penetration flashing rule

Penetrations such as hose bibs and vents need a flanged, sealed flashing that laps the WRB above and is sealed at the face; sealant alone is not an acceptable flashing.

Roof-to-wall termination

At a roof-to-wall junction, the wall WRB laps over the roof flashing and the stucco terminates above the roof with a weep screed or casing bead and sealant joint.

Chimney chase flashing

A chimney chase or bump-out needs a cricket or diverter at the top and base flashing with a drainage path at the bottom to shed water away from the stucco.

Identify system before inspection

Determine whether the wall is three-coat stucco, one-coat stucco, barrier EIFS, or drainage EIFS before judging compliance, because requirements differ by system.

Concealed work verification

Substrate, WRB, lath, flashing, and weep screed must be inspected before they are covered by subsequent coats, since defects cannot be seen afterward.

Moisture meter grid

Take moisture readings on a regular grid across suspect walls and record location, date, and meter mode; confirm elevated readings with a second method or probe.

Delamination sounding test

Tapping the stucco or EIFS lamina with a sounding tool; a hollow sound indicates separation from the substrate and is a reportable defect requiring evaluation.

Report condition versus opinion

A report should state the observed condition and measurement, cite the applicable requirement, and recommend specialist evaluation, clearly separating observation from inferred cause.