EXAMPLE DECK2×10 joist12 ft span · 16″ o.c. · Douglas Fir-Larch
APP SCREEN / EXAMPLE
WHY IT’S USEFUL
Joist capacity changes quickly with species, spacing, and span. The calculator gives you a transparent table-based starting point and shows which smaller members fall short.
WHAT IT DOES
Useful detail without the spreadsheet.
01
Species + spacing
Choose the framing species group and 12-, 16-, or 24-inch on-center spacing used in the deck plan.
02
Load awareness
Set live and dead load, with a clear warning when concentrated loads such as hot tubs require engineered design.
03
Readable comparison
See the minimum joist plus the maximum span for nearby member sizes, not just a single unexplained answer.
USE IT WHEN
The answer needs to travel with the work.
✓Early deck layout and material conversations
✓Checking how spacing changes the minimum joist size
✓Reviewing a simple residential deck against the source table
