The mason is laying a running-bond CMU wall without a special joint profile. Which nominal bed and head joint thickness is the standard layout assumption?
Correct Answer
C) 3/8 in.
Standard modular masonry layout assumes 3/8 in. mortar bed and head joints. Other choices: 1/4 in. is too thin for ordinary modular layout, while 1/2 in. and 5/8 in. change coursing and unit coordination.
Why This Is the Correct Answer
Standard modular masonry layout assumes 3/8 in. mortar bed and head joints.
Why the Other Options Are Wrong
Option A: 1/4 in.
In masonry work, 1/4 in. is the wrong selection for Mortar joints: 1/4 in. is a different published number than the cited Mortar joints value; Mortar joint thickness and modular layout supports 3/8 in.
Option B: 1/2 in.
The trap in B is 1/2 in. That selection is wrong because 1/2 in. is a different published number than the cited Mortar joints value; Mortar joint thickness and modular layout supports 3/8 in.; Standard mortar bed and head joints are nominally 3/8 in.
Option D: 5/8 in.
Choice D (5/8 in.) is rejected because 5/8 in. is a different published number than the cited Mortar joints value; Mortar joint thickness and modular layout supports 3/8 in. The cited answer is 3/8 in.
Memory Technique
Make mortar joints a tabbed card: cite the exact condition, then choose 3/8 in.
Reference Hint
Open Modern Masonry - Brick, Block, Stone, 9th Ed., 2020; use the index entry or section for "Mortar joint thickness and modular layout" to confirm that Standard modular masonry layout assumes 3/8 in.
More NASCLA Questions
Bid instructions require bid security with each sealed bid. Which purpose should the estimator associate with that requirement?
A wood deck surface has 320 sf of coverage. Boards have a 5-1/2 in. actual face width, and the order includes an 8 percent cutting allowance. What linear footage is closest?
Using the dimensions shown for the stabilized construction entrance, what is the plan area?
A reroof area requires 14,720 sf of rigid insulation. Boards are 4 ft by 8 ft, and the order includes 5 percent waste. How many boards are needed?
Two addenda revise the drawings before bid day. What must a responsive bidder normally do with those addenda?
A utility trench is 180 ft long, 3 ft wide, and 7 ft deep with vertical sides inside a trench shield. What excavation volume is required?
A 120 ft long Type C trench is cut with a 4 ft bottom width and a 6 ft depth. If side slopes are 1-1/2 horizontal to 1 vertical, what excavation volume is closest?
A storm pipe run needs 240 ft of bedding, 4 ft wide and 6 in. thick. Including a 10 percent ordering allowance, how many cubic yards of bedding aggregate are needed?
A mass excavation produces 1,180 loose cubic yards of material for off-site disposal. End-dump trucks can haul 18 loose cubic yards per trip. What truck count is required?
An asphalt-shingle roof has a slope of 3:12. Under the IBC low-slope asphalt-shingle provisions, what underlayment arrangement is required?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass