Presets

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Beam Presets

Beams are girders and headers that support other structural members like joists. They typically use multi-ply construction and tributary width loading.

Common Characteristics

Most beam presets share these attributes:

Attribute	Typical Value	Description
n_com	2-3	Number of plies (multi-ply construction)
repeat	"Repeating"	Repetition factor
LTB_bracing	"None"	No lateral bracing assumed
flag_SD	"Yes"	Simplified deflection enabled

Load Format

Beams use explicit tributary width format:

Code
 
["Label", start_ft, end_ft, TW_start_ft, TW_end_ft, {"D": [psf], "L": [psf]}]

Or point loads for joist reactions:

Code
 
["Label", position_ft, {"D": [lbs, moment], "L": [lbs, moment]}]

---

Floor Girder

Multi-ply beam supporting floor joists.

Preset Code: floorGirder

Default Values

Attribute	Value	Description
n_com	3	3-ply beam
repeat	"Repeating"	Repetition factor
LTB_bracing	"None"	No lateral bracing
LLT	"Occupancy"	Floor live load
Delta_Span_ST	360	L/360 short-term
Delta_Span_LT	240	L/240 long-term
Delta_Span_DL+LL	180	L/180 simplified
flag_SD	"Yes"	Simplified deflection enabled

Example with Distributed Loads

Code
 
{
  "preset": "floorGirder",
  "attributes": {
    "L_X": 12,
    "member": "2x12 D.Fir-L No. 1",
    "n_com": 3,
    "supports": [
      ["Pinned", 0, 3.5],
      ["Pinned", 12, 3.5]
    ],
    "loadsDist": [
      ["Floor Load", 0, 12, 7, 7, {"D": [10], "L": [40]}]
    ]
  }
}

Example with Point Loads (Joist Reactions)

Code
 
{
  "preset": "floorGirder",
  "attributes": {
    "L_X": 18,
    "member": "2x12 D.Fir-L No. 1",
    "n_com": 3,
    "supports": [
      ["Pinned", 0, 5.5],
      ["Pinned", 9, 5.5],
      ["Pinned", 18, 5.5]
    ],
    "loadsConc": [
      ["Joist Reaction", 4.5, {"D": [800, 0], "L": [1600, 0]}],
      ["Joist Reaction", 13.5, {"D": [800, 0], "L": [1600, 0]}]
    ]
  }
}

→ Try in API Reference

---

Floor Header

Header beam over openings in floor framing.

Preset Code: floorHeader

Default Values

Attribute	Value	Description
n_com	3	3-ply beam
repeat	"Repeating"	Repetition factor
LTB_bracing	"None"	No lateral bracing
LLT	"Occupancy"	Floor live load
Delta_Span_ST	360	L/360 short-term
Delta_Span_LT	240	L/240 long-term
Delta_Span_DL+LL	180	L/180 simplified
flag_SD	"Yes"	Simplified deflection enabled
doubleCantileverDeflection	"Yes"	Double limits for cantilevers

Example

Code
 
{
  "preset": "floorHeader",
  "attributes": {
    "L_X": 8,
    "member": "2x10 D.Fir-L No. 1",
    "n_com": 3,
    "supports": [
      ["Pinned", 0, 3.5],
      ["Pinned", 8, 3.5]
    ],
    "loadsDist": [
      ["Floor Load", 0, 8, 14, 14, {"D": [10], "L": [40]}]
    ]
  }
}

→ Try in API Reference

---

Ridge Beam (Roof Girder)

Multi-ply beam supporting roof rafters at the ridge.

Preset Code: roofGirder

Default Values

Attribute	Value	Description
n_com	3	3-ply beam
repeat	"Repeating"	Repetition factor
LTB_bracing	"None"	No lateral bracing
LLT	"Occupancy"	Live load type
Delta_Span_ST	180	L/180 short-term
Delta_Span_LT	120	L/120 long-term
Delta_Span_DL+LL	100	L/100 simplified
flag_SD	"Yes"	Simplified deflection enabled
doubleCantileverDeflection	"Yes"	Double limits for cantilevers

Example with Distributed Loads

Code
 
{
  "preset": "roofGirder",
  "attributes": {
    "L_X": 24,
    "member": "2x12 D.Fir-L No. 1",
    "n_com": 3,
    "supports": [
      ["Pinned", 0, 5.5],
      ["Pinned", 12, 5.5],
      ["Pinned", 24, 5.5]
    ],
    "loadsDist": [
      ["Roof Load", 0, 24, 7, 7, {"D": [20], "S": [30]}]
    ]
  }
}

Example with Point Loads (Rafter Reactions)

Code
 
{
  "preset": "roofGirder",
  "attributes": {
    "L_X": 24,
    "member": "2x12 D.Fir-L No. 1",
    "n_com": 3,
    "supports": [
      ["Pinned", 0, 5.5],
      ["Pinned", 12, 5.5],
      ["Pinned", 24, 5.5]
    ],
    "loadsConc": [
      ["Rafter Reaction", 6, {"D": [600, 0], "S": [1200, 0]}],
      ["Rafter Reaction", 18, {"D": [600, 0], "S": [1200, 0]}]
    ]
  }
}

→ Try in API Reference

---

Roof Header

Header beam over openings in roof framing.

Preset Code: roofHeader

Default Values

Attribute	Value	Description
n_com	2	2-ply beam
repeat	"Non-Repeating"	Non-repeating member
LTB_bracing	"None"	No lateral bracing
LLT	"Occupancy"	Live load type
Delta_Span_ST	360	L/360 short-term
Delta_Span_LT	240	L/240 long-term
Delta_Span_DL+LL	180	L/180 simplified
flag_SD	"Yes"	Simplified deflection enabled
doubleCantileverDeflection	"Yes"	Double limits for cantilevers

Example

Code
 
{
  "preset": "roofHeader",
  "attributes": {
    "L_X": 10,
    "member": "4x12 D.Fir-L No. 1",
    "n_com": 2,
    "supports": [
      ["Pinned", 0, 5.5],
      ["Pinned", 10, 5.5]
    ],
    "loadsDist": [
      ["Roof Load", 0, 10, 12, 12, {"D": [20], "S": [30]}]
    ]
  }
}

→ Try in API Reference

---

Deck Beam

Multi-ply beam supporting deck joists with wet service conditions.

Preset Code: deckBeam

Default Values

Attribute	Value	Description
wet	"Wet"	Wet service (outdoor)
n_com	3	3-ply beam
repeat	"Repeating"	Repetition factor
LTB_bracing	"Top Braced"	Top edge braced
LLT	"Occupancy"	Deck live load
Delta_Span_ST	360	L/360 short-term
Delta_Span_LT	240	L/240 long-term
Delta_Span_DL+LL	180	L/180 simplified
flag_SD	"Yes"	Simplified deflection enabled
doubleCantileverDeflection	"Yes"	Double limits for cantilevers

Example

Code
 
{
  "preset": "deckBeam",
  "attributes": {
    "L_X": 14,
    "member": "2x12 D.Fir-L No. 1",
    "n_com": 2,
    "supports": [
      ["Pinned", 0, 4.5],
      ["Pinned", 7, 4.5],
      ["Pinned", 14, 4.5]
    ],
    "loadsDist": [
      ["Deck Load", 0, 14, 8, 8, {"D": [10], "L": [60]}]
    ]
  }
}

Note: Wet service conditions reduce allowable stresses. Consider using pressure-treated lumber or naturally durable species.

→ Try in API Reference

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Combination Beam

Beam supporting combined loading conditions (floor + roof loads).

Preset Code: comboBeam

Default Values

Attribute	Value	Description
n_com	2	2-ply beam
LTB_bracing	"None"	No lateral bracing
LLT	"Occupancy"	Floor live load type
Delta_Span_ST	360	L/360 short-term
Delta_Span_LT	240	L/240 long-term
Delta_Span_DL+LL	180	L/180 simplified
flag_SD	"Yes"	Simplified deflection enabled
doubleCantileverDeflection	"Yes"	Double limits for cantilevers

Example

Code
 
{
  "preset": "comboBeam",
  "attributes": {
    "L_X": 14,
    "n_com": 2,
    "member": "3-1/8x16-1/2 No. 2 DF",
    "supports": [
      ["Pinned", 0, 3.5],
      ["Pinned", 14, 3.5]
    ],
    "loadsDist": [
      ["Roof Load", 0, 14, 12, 12, {"D": [20], "S": [25], "Lr": [20]}],
      ["Wall Load", 0, 14, 8, 8, {"D": [10]}],
      ["Floor Load", 0, 14, 12, 12, {"D": [15], "L": [40]}]
    ],
    "loadsConc": [
      ["Alt Min LL", 7, {"L": [100, 0]}]
    ]
  }
}

Use Case: Combination beams support loads from multiple sources - for example, a beam supporting both floor joists from above and a roof structure.

→ Try in API Reference

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Next Steps

• Joists - Floor, ceiling, deck joists, and rafters
• Special - Generic, flitch, and hip/valley presets
• Attributes Reference - Complete attribute documentation