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

The amount of earth fill needed can be entered
in Part II of the Design Worksheet shown in Ap-
pendix F. The total cost can be estimated from
Table 5.3 above or the cost per cubic yard can be
secured from a local excavation and hauling con-
tractor and applied to the amount of fill required.

Piers
As presented in Chapter IV, piers can be east-
in-place, built-up concrete masonry units, or brick.
The cost of piers will vary due to local material and
labor costs and will also be affected by constant
fixed costs such as contractor equipment set-up.
For instance, the Dodge Manual for Building Con-
struction Pricing and Scheduling shows costs of
$8.86 to $16.76 per linear foot for a cast-in-place
concrete pier 12 inches square, while Marshall and
Swift show $22.50 to $31.00 per linear foot. These
costs do not cover footings, excavation, contrac-
tor set-up, and reinforcement costs.
For the purpose of estimating the cost of a pier
foundation, the general cost ranges per pier shown
in Table 5.4 can be used.
Based on the desired height above grade and
number of piers needed to elevate the manu-
factured home, Part II of the Design Worksheet
in Appendix F can be completed for the purposes
of estimating the design costs. If piers are a design
option, it is strongly suggested that a local con-
tractor cost estimate be secured.
Assuming piers are installed at 10 foot intervals,
the cost per foot of manufactured home, based

3

4

5

on height above grade, is shown in Table 5.5.
-Where additional ground anchors are used, a
cost of $35.00 to $75.00 per ground anchor should
be used.

Post and Piles

Depending upon the anticipated height, spac-
ing, and anticipated loads, a post or pile design
may be an option. The cost of these members will
vary depending upon their length, diameter,and
depth of embedment and will also be impacted by
contractor fixed costs, such as equipment set-up.
Of critical importance is the type of soil and ease
with which these members can be secured in the
ground. Marshall and Swift, for instance, show
$8.20 installed for 10 inch and $10.15 for 12 inch
creosoted wood piles plus fixed set-up costs.
Based on estimates of $10.00 to $15.00 per foot
of length, the general costs shown in Table 5.6
can be used.
Based on the desired height above grade and
number of posts or piles needed to elevate the
manufactured home, Part II of the Design Work-
sheet in Appendix F can be completed for the pur-
pose of estimating the design costs. Not that a
review of local costs will most likely indicate a small
difference in pile costs regardless of diameter such
that use of a larger diameter pile will provide ad-
ditional support and may allow a reduction in the
number of vertical members.
Assuming posts and piles are installed at 10 foot
intervals, the cost per foot of manufactured home,

Table 5.4

PIER COSTS
(dollars)

Height of Pier (ft.)

6

7

8

9

10

Cast-in-Place 150-210 200-280 250-350 300-420 3:;0-490 400-560 450-630 500-700
Built-up Masonry 100-150 133-200 166-250 200-300 233-350 266-400 300-450 330-500
Table 5.5
COST PER FOOT OF MANUFACTURED HOME
(dollars)
Height of Pier (ft .)
3 4 5 6 7 8 9 10
Single Section 20-42 27-56 33-70 40-84 47-98 53-112 60-126 66-140
Double Section 40-84 54-112 66-140 80-168 94-196 106-224 120-252 132-280

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