Bulkhead Components Explained: From Cap to Toe

Inspection reports and contractor quotes describe bulkheads in a specialized vocabulary: wales, deadmen, weep holes, toe stone. Knowing what each term means makes it far easier to follow a recommendation, compare quotes, or describe a problem accurately.

This guide walks through a typical anchored bulkhead from top to bottom and front to back. Not every wall has every part, and names vary by region and material. For how these parts share load, see how bulkhead walls work.

DiagramSimplified illustration — not an engineering drawing

The components at a glance

Above the waterline

Cap

The cap runs along the top of the wall. On concrete canal walls it is often a continuous concrete beam, and the City of Cape Coral's residential seawall permit process, for example, includes a cap and tieback inspection. On timber and vinyl walls it is often a timber or composite cap board. FEMA's example of an anchored sheet pile bulkhead labels this element "coping" and shows a splash apron next to it to reduce overtopping damage.

A cap ties the tops of individual sheets or panels into one line and protects sheet tops from weather and impact. Because it is visible, its alignment is also one of the easiest ways to notice movement. See bulkhead cap repair.

Wales

The USACE homeowner guide defines a wale as a "horizontal beam on a bulkhead used to laterally transfer loads against the structure and hold it in a straight alignment." It notes that wales at or near the top of the wall facilitate construction and distribute anchor loads along the wall. In the trade the word is often spelled or pronounced "whaler." Some walls have more than one row.

Tie rods

Tie rods are steel rods that tie back the top of the wall, as Maryland's guidelines define them. They pass through the wale, run back through the backfill, and connect to an anchor. A VIMS publication's bulkhead schematic shows tie rods with turnbuckles for adjustment.

The USACE guide calls for wrought iron, galvanized, or otherwise corrosion-protected steel and states that plain carbon steel should not be used for long-term protection. A corroded or broken rod is a common reason for the top of a wall to tilt. See tieback and anchor repair.

The wall itself

Sheeting or panels

The sheeting is the face of the wall. Maryland's glossary describes pile sheeting as piles with a slender, flat cross-section driven into the ground and meshed or interlocked with like members to form a wall. The USACE guide lists steel, aluminum and timber sheeting, and state guidance adds vinyl, fiberglass and concrete.

Interlocking steel sheets fit tightly enough that the USACE guide says filters are generally not needed behind them, though weep holes are recommended. Timber sheeting and plank facings have joints that can pass soil, so filter fabric or graded stone behind them is important. Compare materials in our guides to vinyl, steel, timber, concrete and composite sheet piling.

Piles

Piles are long members of timber, concrete or metal driven into the ground for support, according to Maryland's glossary. In a post-supported bulkhead, regularly spaced posts carry the soil load and a facing is attached to them. In sheet pile walls, piles may support the wale and cap. FEMA's anchored bulkhead example shows a round timber pile in the anchor system behind the wall.

Behind the wall

Deadmen and anchors

The USACE guide describes anchors as "a row of piles or line of heavy objects with a large surface area (deadmen) driven or buried a distance behind the bulkhead." Maryland's glossary describes tie backs as piles and rods set in the backfill to provide lateral support. Deadmen may be timber, concrete or other heavy elements, and in some designs anchor piles or brace piles replace them.

Deadmen are rarely visible. Their condition is usually inferred from the wall's behavior or checked by excavation.

Backfill

Backfill is the soil the wall retains. North Carolina's homeowner handbook states that "backfill must be retained for the bulkhead to function," and that cracks or holes let soil escape, weakening support. The USACE guide recommends only granular backfill behind timber bulkheads because it drains freely.

Filter fabric

Filter fabric, or filter cloth, is a synthetic textile placed between the sheeting and the backfill, which VIMS describes as preventing soil loss while providing permeability. USACE notes that untreated synthetic fibers degrade under ultraviolet light and that fabric should be UV-stabilized even when covered, since small openings can admit enough light to cause deterioration.

Installation quality matters as much as the fabric. Maryland's guidelines state that improper installation of filter cloth "has caused more structures to fail than any other contributing factor."

Weep holes

A weep hole is a "hole through a solid revetment, bulkhead, or seawall for relieving pore pressure," in the USACE guide's definition. The guide recommends regularly spaced weep holes in steel sheet pile walls and states that drain holes must always be backed by filter cloth or crushed stone. A weep hole without a working filter can become a path for soil loss. See seawall drainage.

DiagramSimplified illustration — not an engineering drawing

In front of and around the wall

Toe protection and riprap

Toe protection is supplemental armoring of the bottom in front of the wall that prevents waves from scouring and undercutting it, as the USACE guide describes. It is commonly riprap, which VIMS defines as hard, angular stone that will not disintegrate from exposure to water or weathering. Maryland's guidelines recommend armor stone over a bedding layer of small stone and filter cloth, which reduces the chance of tearing the fabric.

Splash apron

A splash apron is a structural component, often rock, that prevents waves from scouring material from the top of a revetment or bulkhead, according to VIMS. The USACE guide suggests one where it is impractical to build a wall high enough to prevent overtopping.

Return walls

Return walls are end sections set perpendicular to the shoreline. VIMS describes them as tying the bulkhead into the upland to prevent it from being flanked as the shoreline retreats on either side. The USACE guide notes that flank protection is important because erosion could otherwise continue around the ends.

How components fail together

Components rarely fail alone. A typical sequence might start with a corroded tie rod. The top of the wall rotates slightly, joints open, and the filter fabric tears or pulls away. Backfill then washes out with each tide, leaving voids that appear as sinkholes behind the cap. In another sequence, scour removes soil at the toe, the base kicks outward, and the same soil loss follows.

The visible symptom is often far from the original cause. That is why a professional assessment looks at the whole system. See signs of bulkhead failure and why is my yard sinking behind my seawall.

Recording what your wall has

A short component record is useful before any inspection or quote:

1. Wall material and whether the face is sheet piling or a facing on posts.
2. Cap material and whether its line looks straight.
3. Whether wales and tie rod ends are visible on the face.
4. Whether weep holes are present and whether soil stains appear below them.
5. Whether stone protects the toe, and its condition at low tide.
6. How each end of the wall meets the bank or the neighboring wall.

The inspection checklist and the bulkhead inspection guide build on this list.