Materials & Equipment Knowledge Flashcards
7 cards from real CRC practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 7 Materials & Equipment Knowledge flashcards as text
What is the maximum allowable gap between a roof sheathing panel and the next panel to allow for expansion?
Answer: 1/8 inch
APA recommendations call for a 1/8-inch spacing between roof sheathing panels to allow for expansion due to moisture and temperature changes.
Which masonry unit type is classified as 'lightweight' and has a maximum density of 105 pcf?
Answer: Lightweight CMU
ASTM C90 classifies lightweight concrete masonry units (CMU) as having an oven-dry density of 105 pcf (pounds per cubic foot) or less.
What is the primary purpose of a capillary break between a concrete foundation and wood sill plate?
Answer: To prevent moisture from wicking up from concrete into wood
A capillary break, typically a sill gasket or sill seal, prevents concrete from wicking moisture up into the wood sill plate through capillary action.
Which gypsum board type is designed specifically for use in high-humidity areas such as bathrooms and should be used as a backer for tile?
Answer: Cement backer board
Cement backer board is the appropriate substrate for tile in wet areas because it will not deteriorate when exposed to sustained moisture, unlike gypsum products.
A residential contractor is installing CPVC pipe for a hot water supply line. What solvent cement color is typically used for CPVC?
Answer: Purple primer, then gray or orange cement
CPVC requires purple primer followed by yellow or orange CPVC-rated solvent cement; using PVC cement on CPVC creates a weak joint that can fail.
What is the minimum thickness of rigid foam insulation required beneath a concrete slab on grade to qualify as 'continuous insulation' under most energy codes?
Answer: 1 inch
Most energy codes require at least R-5 (approximately 1 inch of EPS or XPS) beneath a heated slab on grade to reduce conductive heat loss to the ground.
Which type of flashing material is NOT compatible with cedar or redwood siding due to chemical reactions that cause corrosion?
Answer: Aluminum
Aluminum flashing corrodes rapidly when in contact with cedar or redwood because the tannic acid in these woods reacts with aluminum.