Construction Materials and Methods
Materials and Assemblies
Know common structural and finish materials: concrete (mixing, curing, reinforcement), masonry (mortar, flashing, weep holes), wood (grading, moisture content, fasteners), steel, and gypsum assemblies. Understand concrete curing, control joints, and the role of reinforcement. Know masonry wall drainage: flashing, weep holes, and cavity. Understand wood shrinkage and the need for correct fasteners and connectors.
Traps to Watch
Questions often test that concrete gains strength over time and must be cured, not just dried. Watch for masonry walls missing weep holes or flashing, which trap water. Another trap is using the wrong fastener for treated wood or dissimilar metals, causing corrosion. Know that control joints manage cracking but do not eliminate it.
Worked Example
A brick veneer wall shows efflorescence and water staining at the base. Rule of thumb: veneer is a drainage wall. It needs a flashing at the base with weep holes and a clear air cavity. If weep holes are blocked by mortar, water accumulates and migrates inward. The fix is restoring drainage, not sealing the face of the brick.
Key Points
- Concrete must be cured to develop design strength.
- Control joints manage, not eliminate, cracking.
- Masonry veneer relies on flashing and weep holes.
- Fasteners must suit the material and treatment.
- Dissimilar metals can cause galvanic corrosion.