Interior Construction, Materials, and Specifications
This domain tests interior construction, materials, and specifications: how partitions, ceilings, floors, doors, hardware, and finishes are selected, detailed, and specified. Expect questions on fire ratings, acoustic assemblies, substrate and finish compatibility, and specification format.
Core rules
- Match the assembly to the performance requirement: fire-resistance (ASTM E119), surface burning (ASTM E84), acoustic (ASTM E90/E413), and durability.
- Specify by reference standard and performance criteria; avoid vague 'or equal' language without a basis of design.
- Use CSI MasterFormat divisions for organization (Division 09 finishes, Division 08 openings, Division 10 specialties).
- Coordinate wall thickness, door frames, casework, and ceiling heights; a nominal 2x4 wall is not 4 in thick after finishes.
- In wet areas and food service, specify substrates, sealants, and slip resistance, not just the finish color.
Worked example
A 40-ft-long, 9-ft-high corridor partition has one 3-ft by 7-ft door. One side: 40 x 9 = 360 sf; subtract 21 sf = 339 sf. Both sides = 678 sf. Add 10% waste = 746 sf. At 32 sf per 4x8 sheet, 746 / 32 = 23.3, so order 24 sheets per layer. If the assembly is a 1-hour rated partition, confirm the listed assembly, type X board, studs, insulation, and penetration details; the quantity calculation does not make it rated.
Traps
- Confusing fire rating with STC or NRC.
- Forgetting both sides of a partition, openings, waste, or ceiling height.
- Specifying a finish that cannot bond to the substrate or that exceeds the flame-spread class for a corridor.
- Using a door leaf size as clear width; frames and stops reduce it.