FLOOD02929

• County: Statewide
• Community: na
• Basin: Statewide
• Title: Manufactured Home Installation in Flood Hazard Areas
• Date: 9/1/1985
• Prepared By: FEMA
• Floodplain - Doc Type: Educational/Technical/Reference Information

a = Chassis I-beam spacing (in)
As discussed in Section B of Chapter IV, the following design conditions were used.
Rf = 20, 30 or 40 psf based on roof live load zone (figure 4.1)
Ar = Width (W) X length (L) (including eaves)
Df = 20 psf
Ff = 40 psf
Af = Width (W) X length (L)
h = 9.75 ft.
Wf = 15 or 25 psf based on wind load zone (Figure 4.2)
a = 75 1/2 in., 82 in., and 99 in.
s = 5, 6, 7, 8, 9, and 10 ft.

Pier Design
As presented in Section B of Chapter IV, various pier designs in Table 4.11 are recommended based
on the anticipated loads which impact the manufactured home and are transferred to the pier. The recom-
mended pier designs were determined using the interaction equation as follows:

fa + fb
1.33 = Fa Fb

Where:

fa = computed axial stress in psi
= [W x s x 60] -;- Ap
Where:
W = Outside width of manufactured home (ft)
s = Vertical member spacing (ft)
Ap = Cross sectional area of pier (in2)

fb = Horizontal loading in psi
= [Wf x h x s x f x 12] -;- Sx
Where:
Wf
h
s
Sx
f
= 0.20 f'm

= 0.30 f'm
Where:
f'm = Strength of concrete (psi)

The following design conditions were used in calculating the acceptable conditions under which pier
failure would not occur for the pier designs in Section B of Chapter IV.
W = 12 and 14 ft.

s = 5, 6, 7, 8, 9, and 10 ft.
We = 15 and 25 psf.

f'm = 1500 and 2500 psi.
f = 5,6,7,8,9,10,11,12,13, 14, and 15 ft.

Sx = Based on pier designs A-F

Ap = Based on pier designs A-F

Fa
Fb

= Lateral windload (psI)
= Outside height of manufactured home (ft)
= Vertical member spacing (ft)
= Section modulus of pier (in3)
= Length of pier (ft)

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