Question 1

Control joints are required to be more closely spaced on a stucco surface backed by a stud wall than on a stucco surface backed by a masonry wall.

Accepted Answer

This is because stud walls have more movement and flexibility than masonry walls, which can cause stress and cracking in the stucco surface. Therefore, control joints need to be spaced closer together to accommodate this movement and prevent damage.

Question 2

On wood- stud and cold- formed steel- stud- wall assemblies, stucco is typically applied in three coats. Beginning from the first to the last, the coats are generally called

Accepted Answer

The three coats of stucco applied on wood-stud and cold-formed steel-stud-wall assemblies are typically called the scratch coat, brown coat, and finish coat, in that order. The scratch coat provides a good base for the stucco, the brown coat evens out the surface, and the finish coat is the final, visible layer.

Question 3

The term EIFS is an acronym for

Accepted Answer

The term EIFS stands for Exterior Insulation and Finish System.

Question 4

In addition to water, a stucco base coat mix consists of

Accepted Answer

A stucco base coat mix typically consists of Portland cement, lime, and sand. These ingredients work together to create a strong and durable base layer for the stucco finish coat. Glass fibers are sometimes added to the mix to increase its strength and flexibility, but they are not a standard ingredient in stucco base coat mixes. Gypsum is a common ingredient in plaster, but it is not typically used in stucco base coat mixes.

Question 5

The thickness of the lamina in PB EIFS is approximately

Accepted Answer

The thickness of the lamina in PB EIFS is approximately 1/8 in. This information can be found in the technical data sheet provided by PB EIFS manufacturers.

Question 6

The total thickness of stucco on a concrete or concrete masonry wall is generally

Accepted Answer

Since concrete and concrete masonry walls are already solid and durable, they do not require as much thickness in the stucco layer as stud-backed walls which require a thicker layer to compensate for the lack of structural stability. Therefore, the total thickness of stucco on a concrete or concrete masonry wall is generally smaller than that on a stud-backed wall.

Question 7

Control joints on a stucco surface are formed by using accessories, which consist of

Accepted Answer

Control joints on a stucco surface can be formed using accessories made of zinc, galvanized steel, or PVC, making any of these materials a suitable choice.

Question 8

EIFS is classified into two categories: polymer- based (PB)EIFS and polymer- modified (PM)EIFS. Which of these two is more commonly used?

Accepted Answer

PB EIFS (Polymer-Based Exterior Insulation and Finish Systems) are more commonly used due to their comprehensive system that includes a fully adhered, water-resistant barrier and insulation board, making them a popular choice for both residential and commercial buildings for their energy efficiency and aesthetic flexibility.

Question 9

In an adhered masonry veneer, the most commonly used masonry unit is

Accepted Answer

Lightweight manufactured stone is the most commonly used masonry unit in adhered masonry veneers due to its ease of installation, cost-effectiveness, and aesthetic versatility.

Question 10

Masonry units in an adhered masonry veneer

Accepted Answer

Grouting of joints is typically done after the masonry units are adhered to ensure the joints are properly filled and sealed.

Question 11

Metal lath is required when stucco is applied on

Accepted Answer

Metal lath is specifically required for stucco application on stud-wall assemblies because these structures do not inherently provide a sufficient base for the stucco to adhere to, unlike concrete or masonry walls which can often support stucco directly.

Question 12

In PB EIFS, the insulation commonly used is

Accepted Answer

Expanded polystyrene (EPS) is the most commonly used insulation in PB EIFS. It offers good thermal insulation properties, is lightweight, and easily shaped to fit the contours of the building. Polyisocyanurate and extruded polystyrene are also used, but not as commonly as EPS. Fiberglass is not typically used as insulation in EIFS systems.

Question 13

Control joints on a stucco surface are provided primarily to

Accepted Answer

Control joints in a stucco surface are primarily provided to control drying shrinkage of the stucco. This helps to prevent cracking by accommodating the shrinkage as the stucco dries and cures.

Question 14

On wood- stud and cold- formed steel- stud- wall assemblies, stucco is typically applied in three coats. The total typical thickness of the three coats is

Accepted Answer

The typical total thickness of the three coats of stucco applied on wood-stud and cold-formed steel-stud wall assemblies is 7/8 inch.

Question 15

The required color of a stucco surface is

Accepted Answer

The required color of a stucco surface is typically achieved by adding integral color to the mix of the finish coat. This ensures a consistent color throughout the entire stucco surface and eliminates the need for additional painting or coloring after the finish coat has fully cured.

Question 16

When control joints are provided in a stucco- clad wall, expansion joints are unnecessary.

Accepted Answer

Control joints are provided to allow for minor movement and prevent cracking, but they do not accommodate for major expansion and contraction. Therefore, expansion joints may still be necessary in certain situations.

Question 17

Masonry units in an adhered masonry veneer on a stud wall are applied directly on

Accepted Answer

Adhered masonry veneer is typically applied over a stucco scratch coat over metal furring lath to ensure proper adhesion and support.

Question 18

In PB EIFS, the EIFS lamina consists of

Accepted Answer

The EIFS lamina consists of a base coat, mesh, and finish coat. Insulation is incorporated into the system separately. Lath is also not a part of the EIFS lamina.

Question 19

In an adhered masonry veneer, masonry units are adhered to the backup surface using

Accepted Answer

Polymer-modified masonry mortar is the most commonly used adhesive for adhered masonry veneer. It provides a strong bond and excellent resistance to water and other environmental factors. Epoxy resin and acrylic polymer bonding agents can also be used, but they are typically more expensive and may require special handling and equipment. Portland cement slurry is not typically used as an adhesive for adhered masonry veneer.

Question 20

Metal lath, when used in stucco, is installed on the wall

Accepted Answer

Metal lath is installed on the wall before the application of the first stucco coat to provide a strong mechanical bond and support for the stucco layers.

Quiz 29: Exterior Wall Cladding-III Stucco, Adhered Veneer, Eifs, Natural Stone, and Insulated Metal Panels