Example
A 1.75×11.25 in. LVL beam spans 14 ft + 14 ft (two spans, pinned interior support). Uniform dead 25 plf, live 100 plf. Plus point load 500 lb at 7 ft from left (concentrated load from column or beam). Check per NDS 2024. CD = 1.0 for D+L.
How StructSuite solves this
StructSuite's free wood beam calculator NDS: select Floor Joist, Design per NDS. Enter spans [14, 14], supports pinned-pinned-pinned. Add uniform load D 25 plf, L 100 plf. Add point load 500 lb at 7 ft. Select product LVL, species/grade. StructSuite runs beam analysis; two-span has negative moment at interior support. LVL from NDS Supplement or manufacturer ESR.
Steps
- Step 1: Select member type
Design consideration: LVL has higher Fb than sawn—typically 2–3× for same depth. Used for headers 14–24 ft, girders. 1.75×11.25 common; deeper for longer spans. Manufacturer ESR required—Fb, Fv vary by product. No IBC span tables for LVL.
In StructSuite: In the "Select member type" section at the top, click the Floor Joist card.
- Step 2: Select design method
Design consideration: NDS with product-specific values. Two-span: negative moment at interior often governs. Point load + uniform: check moment at point, at interior support, and midspan. LVL stiffness (E) higher—deflection less critical than sawn.
In StructSuite: In the "Select design method" section, click the "Design per 2024 NDS (National Design Specification for Wood Construction)" card.
- Step 1: Geometry & Configuration
Design consideration: 14+14 ft = 28 ft total; interior support gets large negative moment. Point load at 7 ft creates local moment peak. Deeper LVL (14 in., 16 in.) for 20+ ft. Manufacturer span tables available for quick check.
In StructSuite: Open the Geometry section. In the beam schematic, enter span lengths: 14, 14. For each support, use the support type dropdown to select: Pinned, Roller, Pinned. NDS 2024 Eq 3.3-1, 3.4-2 for flexure and shear.
- Step 2: Load Definition (ASCE 7-22 / NDS 2024)
Design consideration: 125 plf uniform + 500 lb point. Point at 7 ft from left: adds moment; combined with uniform, governing may be at point or interior. Tributary from floor: 25 plf D ≈ 2 ft width × 12.5 psf. 500 lb from column, beam, or concentrated load.
In StructSuite: Open the Loads section. Add load items with these exact values: D 25 plf; L 100 plf; 500 lb at 7 ft. For each uniform load: set Type (D, L, Lr, S), enter the plf value in Uniform (plf). For point loads: set category Point, enter magnitude (lb) and position (ft). Include self-weight. NDS 2024 Table 2.3.2 sets CD.
- Step 3: Material & Section
Design consideration: LVL CF often 1.0 (no size factor for typical depths). Wet service: check manufacturer. No Cr for single beam. Deflection L/360; LVL stiffness helps. Microllam 2.0E common; 1.5E for lower grade.
In StructSuite: Open the Materials section. In Product category select the type; in Species select Microllam (Weyerhaeuser); in Grade select 2.0E; in Size select 2.0E LVL 1.75x11.25. Open Design Parameters: set Wet service (CM) to No; set Repetitive member to No; select Deflection limit. NDS 2024 §4.3.
Live design (pre-filled)
The form below is the real StructSuite module with example data loaded. Display only—values cannot be changed.
Select member type
Select design method
Floor Joist — Design per 2024 NDS
National Design Specification for Wood Construction