Masonry Construction: Masonry Wall Construction

Question 1

What are the five types of masonry walls?

Answer 1

• composite masonry walls (traditional or contemporary)
• masonry cavity walls
• masonry load bearing walls
• reinforced masonry walls
• post-tensioned masonry walls

Question 2

What are composite masonry walls? (3)

Answer 2

• use different masonry materials in different parts of the wall
• exterior face of stone, brick, or other masonry material
• inner wythes of less expensive CMU or clay units

Question 3

How are solid wythes bonded in composite masonry walls?

Answer 3

• header units

- metal ties or reinforcing

Question 4

What are masonry cavity walls? (3)

Answer 4

• multi-wythe
• a continuous air space between wythes acts as an internal drainage plan
• water that penetrates the outer wythe runs down the cavity and is drained back to the exterior through weep holes

Question 5

What is a cavity?

Answer 5

minimum recommended width is two inches to allow space for masons to keep the cavity clear of mortar droppings during construction

Question 6

What are weep holes?

Answer 6

allow water to drain from wall cavity

Question 7

What is flashing?

Answer 7

continuous waterproof membrane that intercepts water in the cavity and directs it to the exterior through weep holes

Question 8

What bonds wythes across the cavity?

Answer 8

corrosion-resistant metal ties

Question 9

What is insulation?

Answer 9

water-resistant insulation boards can be inserted into the cavity, but a minimum of one inch of clear airspace should be preserved

Question 10

What are load bearing masonry walls? (3)

Answer 10

• carry gravity loads from floors and roofs
• may be composite, cavity, or single-wythe
• in load bearing cavity walls, the inner wythe is usually load bearing and the outer wythe or veneer is nonstructural

Question 11

What are reinforced masonry walls? (2)

Answer 11

• vertical reinforcing bars in grouted cells

- horizontal joint reinforcing

Question 12

What does reinforcing provide?

Answer 12

• greater strength
• improved resistance to lateral forces
• thinner walls when compared to reinforced masonry

Question 13

What are post-tensioned masonry walls? (4)

Answer 13

• steel plates placed at top of CMU wall
• high strength threaded steel rods or cables anchored to foundation
• after mortar has cured, steel rods are placed in tension
• places wall in compression and strengthens wall against tensile forces

Question 14

Why are post-tensioned masonry walls used?

Answer 14

allows the use of thinner walls with fewer grouted cores

Question 15

What is thermal insulation? (3)

Answer 15

• masonry tends to conduct heat which means it is a poor insulator
• therefore, thermal insulation needs to be part of the design for exterior masonry walls
• thermal insulation can be applied to the outside face of a masonry wall, interior face of a masonry wall, or within the wall

Question 16

What insulation is used for exterior faces?

Answer 16

rigid foam, part of an Exterior Insulation and Finish System (EIFS), can be applied to the exterior side of a masonry wall

Question 17

What insulation is used for cavities?

Answer 17

rigid foam or mineral fiber boards can be inserted into the masonry wall cavity

Question 18

What is core insulation? (2)

Answer 18

• CMU cores can be insulated with loose granular insulation or rigid foam inserts
• proprietary CMUs with special insulating foam inserts can improve energy efficiency by reducing thermal bridging

Question 19

What insulation is used for the interior?

Answer 19

rigid foam boards can be fastened to the interior side of a CMU wall with vertical metal furring

Question 20

What does EIFS stand for?

Answer 20

Exterior Insulation and Finish System