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Reinforced Masonry Pier Construction
Home Builder’s Guide to Coastal Construction
FEMA 499/June 2005
Technical Fact Sheet No. 14

Purpose: To provide an alternative to piles in V zones and A zones in coastal
areas where soil properties preclude pile installation, yet the need for an
“open foundation system” still exists. Examples of appropriate conditions for
the use of piers are where rock is at or near the surface or where the potential
for erosion and scour is low.

Key Issues
--The footing must be designed for the soil conditions present. Pier foundations
are generally not recommended in V zones or in A zones in coastal areas.
--The connection between the pier and its footing must be properly designed and
constructed to resist separation of the pier from the footing and rotation to
due to lateral (flood, wind, debris) forces.
--The top of the footing must be below the anticipated erosion and scour depth.
--The piers must be reinforced with steel and fully grouted.
--There must be a positive connection to the floor beam at the top of the pier.
--Special attention must be given to the application of mortar in order to
prevent saltwater intrusion into the core, where the steel can be corroded.

Piers vs. Piles
Graphic:
Piers are subject to upward, downward, and horizontal loads. Pier reinforcement
and footing size are critical to resisting these loads; therefore, pier and
footing design must be verified by an engineer.

Pier: used only where the potential for erosion and scour is low or where the
pier can be anchored to underlying bedrock or other stratum that terminates
erosion and scour.
Pile: used where the potential for erosion and scour is high.

In coastal areas, masonry pier foundations are not recommended in V zones with
erodible soils, or in A zones subject to waves and erosion—use pile foundations
in these areas.

Pier foundations are most appropriate in areas where:
--erosion and scour potential are low,
--flood depths and lateral forces are low, and
--soil can help resist overturning of pier.

The combination of high winds and moist (sometimes salt-laden) air can have a
damaging effect on masonry construction by forcing moisture into even the
smallest of cracks or openings in the masonry joints. The entry of moisture into
reinforced masonry construction can lead to corrosion of the reinforcement steel
and subsequent cracking and spalling of the masonry. Moisture resistance is
highly influenced by the quality of the materials and the quality of the masonry
construction at the site.

Graphic: The small footings on the piers in this photograph did not prevent
these piers from overturning during Hurricane Iniki.

Good Masonry Practice
--Masonry units and packaged mortar and grout materials should be stored off the
ground and covered.
--Masonry work in progress must be well protected.
--Mortar and grouts must be carefully batched and mixed. The 2003 International
Building Code (IBC 2003) specifies grout proportions by volume for masonry
construction.

Recommendations for Masonry Piers in Coastal Regions
--Head and bed joints must be well mortared and tooled to prevent water
intrusion. Type S mortar for below grade is recommended. Concave joints and v-
joints provide the best moisture resistance.
--Reinforcing bars must be protected from saltwater to prevent corrosion. Good
grout practice will normally protect reinforcing. Galvanized or epoxy-coated
bars may enhance pier performance, but holidays and chipped coatings must be
painted, and lap splice lengths must be increased by 50 percent for epoxy-coated
bars.
--Grout should be in conformance with the requirements of the IBC 2003.
Cleanouts should be placed at the bottom of fully grouted cells to ensure that
the grout completely fills the cells from top to bottom.