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

Connections

Vertical Member to Horizontal Beam

The vertical member loads presented in Table 4.10 are directly transferred to the connection of the
vertical member and horizontal beam. The number of bolts of a given size are determined as follows:

Fr/Q or Fw/Q (whichever is greater)

Fr = Vertical member load <Ib) from Table 4.10 or calculated for other conditions
or
Fw

Q = Bolt design capacity (I b)

The bolt design capacity is based on the type of wood, length of bolt in the horizontal beam, diameter
of bolt and direction of load to wood grain.
The values in Tables 4.21 and 4.22 of the manual were derived from the vertical member loads in
Table 4.10 at the stated design conditions and the following bolt design values for spruce-pine- fir, setka
spruce, yellow poplar, and eastern spruce and lodgepole pine.

Q - Bolt Design Value (Ib)
Horizontal Beam Size

Bolt Diameter (in) 2@3 in. 4@~in. 4@3 in.

5/8 990,0 1012.5

3/4 1170.0 1295.0

7/8 1290.0 1505.0 1 (\15.0

1 1410.0 1687.5 2147.5

11/4 1655.0 1985.0 3117.5

To be capable of supporting the imposed load the total bolt capacity (bolt design value x no. bolts)
must be greater than or equal to the vertical load from Table 4.1 0 or calculated as previously discussed.

Chassis I-beams
The lag screws used to connect the chassis I-beam clips to the horizontal beam must be capable
of resisting uplift and shear loads resulting from wind.
The lateral wind load per vertical member is calculated as follows:

= [(~)(12)(Wf)(S)(h)]

W'e

a

Where:
W'f = Lateral wind load per vertical member (I b)
h = Manufactured home height (ft)
Wi = Lateral wind load (pst)
s = Vertical member spacing lengthwise (ft)
a = I-beam spacing
The uplift wind load per vertical member is calculated as follows:
W'u = [(Wu)(s)(W)] + 2.5Wu[(s)(W + 2)]
2

95