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Five of 115 scored questions covering framing members and load paths, fasteners and shear walls, and engineered wood, trusses and temporary bracing.
Five questions, and the material most residential-background contractors find easiest.
The three subtopics
- Framing members, spans and load paths
- Fasteners, connectors and shear walls
- Engineered wood, trusses and temporary bracing
Spans are lookups
Allowable span depends on species, grade, spacing and load, and it is read from a table in the code. Nobody is expected to know it.
Which makes span questions pure navigation. Tab the span tables and they become quick marks; leave them untabbed and each one costs three minutes.
Load paths
The idea that load travels from roof to foundation through a continuous path, and that any interruption has to be carried by something.
Questions describe a modification and ask what it affects. Understanding the path answers them without a lookup.
Temporary bracing during erection is the contractor's responsibility, and trusses are unstable until it is in place. A collapse during erection is a recurring scenario in this category and the answer is about the contractor's duty rather than about the truss design.
Shear walls
Resist lateral load in the plane of the wall. The sheathing, the nailing pattern and the hold-downs all matter, and altering any of them alters the capacity.
Moisture
Nineteen percent moisture content is the usual threshold above which lumber is considered green. It affects shrinkage, fastener performance and finish work applied over it.
Common questions
How many wood questions are on the NASCLA exam?
5 of the 115 scored questions.
Do I need to memorize span tables?
No. They are lookups, which makes tabbing them worthwhile since each untabbed lookup costs minutes.
Who is responsible for temporary truss bracing?
The contractor. Trusses are unstable until it is in place and collapse during erection is a recurring exam scenario.
What is a shear wall?
A wall resisting lateral load in its own plane, through sheathing, nailing pattern and hold-downs.
What moisture content counts as green lumber?
19 percent is the usual threshold.