Calculate maximum spans for ceiling joists in attics
For attic not accessible by a stairway
Maximum Allowable Span
5.37 m
Calculation Details
Species:Douglas Fir - Larch
Grade:Select Structural
Size:38 x 140 mm (2 x 6)
Spacing:300 mm (12 in)
Application:Attic not accessible by stairway
⚠️ Important Disclaimer:
This calculator is for reference only and provides preliminary estimates based on BC Building Code 2018 Table 9.23.4.2.-C.
Always consult with a qualified structural engineer or building professional for structural design and code compliance verification.
Important Notes:
• These spans apply to ceiling joists in attics not accessible by a stairway
• Deflection limits and loading assumptions are per BC Building Code requirements
• For accessible attics or storage areas, different span tables apply
• Proper bearing and connection details must be followed per Code requirements
Main Index