# TR.20.9 Applying Fireproofing on members

STAAD.Pro includes a method to automatically consider the weight of fireproofing material applied to structural steel.

## General Format

`MEMBER FIREPROOFING`
`member-list FIRE { BFP | CFP } THICKNESS f1 DENSITY f2`

Where:

ParameterDescription
THICKNESS f1 thickness (T in the figures below) in length units
DENSITY f2 density of fireproofing material in (force / length3) units

In the actual load case itself, nothing besides the SELFWEIGHT command is necessary to instruct the program to include the weight of the fireproofing material in the selfweight calculation.

Two types of fireproofing configurations are currently supported. They are:

• block fireproofing
• contour fireproofing

## Block Fireproofing (BFP)

The following figure shows this configuration. The fire-protection material forms a rectangular block around the steel section.

The area of fireproofing material (Afp) at any section along the member length is calculated in the following manner.

For Wide Flanges (I-shaped sections), Channels and Tees,

Afp = [(Bf + 2T)*(D+2T)] - Asteel

For single angles,

Afp= [(Bf + 2T)*(D+2T)] - Asteel

where
 Bf = the flange width D = the overall depth of the steel section T = the thickness of the fireproofing material beyond the outer edges of the cross section as dimensioned in the next figure Asteel = area of the steel section

Where:

## Contour Fireproofing (CFP)

In this configuration, the fire-protection material forms a coating around the steel section as shown in the next figure. The area of fireproofing material (Afp) for this case is calculated in the following manner.

For Wide Flanges (I-shaped sections)

Afp = [(Bf + 2T)*(Tf+2T)]*2 + [(D-2T-2Tf)*(Tw+2T)] - Asteel

For single angles,

Afp = [(L1+2T)*(2T+Ta) + (L2-Ta)*(2T+Ta)] - Asteel

For Tees,

Afp = [(Bf + 2T)*(Tf+2T)] + [(D-Tf)*(Tw+2T)] - Asteel

where
 Bf = the flange width D = the overall depth of the steel section T = the thickness of the fireproofing material beyond the outer edges of the cross section as dimensioned in the next figure Tf = the thickness of the flange for the I shape and Tee Ta = the thickness of the leg of the angle Tw = the thickness of the web for the I shape and Tee Asteel = area of the steel section

### Contour fireproofing (CFP) on various shapes

The number of input items required to apply this attribute is:
1. the type of fireproofing
2. the thickness T shown in the above figures
3. the density of the fireproofing material
4. the members on which it is to be applied

For each such member, Afp is calculated and multiplied by the density of the fireproofing material to obtain the weight per unit length of the member. This is added to the weight per unit length of the steel section itself and the total is used in calculating selfweight. Hence, SELFWEIGHT must be one of the load components of load cases if the weight of the fireproofing material should be considered as part of those load cases.

## Notes

1. STAAD calculates the fire proofing weight only for the following sections:

For block fireproofing - I-shaped sections like those from the built-in tables (American W,S,M,HP, British UC and UB, etc.), tapered I shaped sections, single channels, angles and Tees.

For CFP-contour fireproofing - the sections are I-beam straight or tapered, angle, Tee.

I-shaped sections like those from the built-in tables (American W,S,M,HP, British UC and UB, etc.), tapered I shaped sections, angles and Tees..

2. Fire proofing weight is not calculated for the following section types: Pipe, tube, composite I beams with slab on top, double channel, double angle, HSS, I-beam with cover plates, prismatic, solid circle or rectangle, castellated, cold formed sections, wood, aluminum, tapered poles, etc.

## Example Problem

``````STAAD SPACE
UNIT KIP FEET
JOINT COORDINATES
1 0. 0. ;2 0. 15. ; 3 20. 15. ;4 20. 0.
MEMBER INCIDENCE
1 1 2 ; 2 2 3 ; 3 3 4
MEMBER PROPERTY AMERICAN
1 3 TABLE ST W12X26
2 TABLE ST W14X34
CONSTANTS
E  STEEL ALL
POISSON STEEL ALL
DENSITY STEEL ALL
SUPPORT
1 FIXED ; 4 PINNED
UNIT POUND INCH
MEMBER FIREPROOFING
1 3 FIRE BFP THICK 2.0 DENSITY 40
2 FIRE CFP THICK 1.5 DENSITY 40
UNIT KIP FT