Throughout various industries, a multitude of individuals refer to all vertical shoreline structures as “seawalls” however, there is a dramatic difference between a seawall and a bulkhead:
A wall or embankment erected to prevent the sea from encroaching on or eroding an area of land but also retains soil.
A retaining structure of timber, steel, or reinforced concrete, used for shore protection and provides minimal protection from waves.
Seawalls are usually located on coastal fronting bays and canals throughout Southwest Florida. Wood Bulkheads are located primarily on freshwater lakes in golf course communities.
TIMBER BULKHEAD CONSTRUCTION
As is with most significant factors in life, natural deterioration and age leads to the expected weakening of the wooden structure over time. A bulkhead or components of a wood seawall are relentlessly subjected to harsh natural environmental factors such as water/rainfall, which are specifically corrosive elements found in Southwest Florida. Over time, corrosion of the galvanized hardware and cables along with deterioration of wood seawall structural components can advance seawall failure.
A timber sheet/wale/pile system is a popular wood bulkhead structural configuration used throughout our geographical area. Most of the developers who had golf courses constructed , selected wood bulkheads because of generally economical material.
Bulkheads in Southwest Florida were primarily constructed when lakes were excavated first and then the bulkheads installed dry (meaning no water in the lake). First, the process commenced with driving/vibrating the wood piling into substrate to support the wall. Next, horizontal whalers were installed usually a 3” x 8” and attached to the wood pile with galvanized fasteners. Then install the 2” x 8” vertical wood sheathing that constitutes the bulk of the wood bulkhead. These timbers were nailed into the whalers with 20D nails. After that is complete, a layer of filter cloth was then draped across the entire back of the structure to prohibit soil from escaping from the uplands. Finally, the structural task was to install a dead-men and tie-back system to hold the wall in vertical alignment. This usually consisted of driving a pile 12 foot behind the wall and connecting a ½” galvanized cable or piece of all-thread to the piling sustaining the wood wall.
WOODEN BULKHEAD LONGEVITY
The wooden walls all have minimal preservative treatment as they are not as essential in freshwater lakes as they are in harsh saltwater environments. Heavier chemical treatments are required for service in warm saltwater environments where marine organisms and teredo worms (water- borne termites) exist that cause piling decay. The life expectancy of a wood golf course wall is typically less than 25 years.
IMMINENT SIGNS OF FAILURE
- Bowing or tilting of wall
- Erosion behind the bulkhead
- Bulkhead rotating out at base
- Wooden pilings with wear and decay
- Top cap in poor condition
- Missing pieces
BULKHEAD LEANING OUT
Another main problem to be visually aware of is if the top of the wall is leaning out. This predominately occurs on wood bulkhead walls over time (15 to 20 years) and is a major indication that some, or all, of the tie-back rods have decomposed. If the whalers, piling, and sheeting all look fine, but the bulkhead is leaning out at the top, your tie-back rods are gone.
This situation must be remedied quickly, otherwise the bulkhead will completely fail and collapse into the lake. There is an immediate decision that will have to be made which will influence the cost of the repair. The choice to just stabilize the bulkhead, or to “pull” the bulkhead back into its original position?
The steps to stabilize the wood bulkhead and prevent further leaning or collapse of the bulkhead depends on the location of bulkhead. Our seawall tie-back anchor helical systems will prevent the collapse of your wall and extend its life longevity.
SINKHOLES (EROSION HOLES)
Sinkholes or voids are an early warning that you may be facing imminent wall failure. Upland soils are washed out by continuous broken sprinkler heads, water movement, and rainfall events, voids begin to appear behind the bulkhead and can escalate to further complications, such as sinkholes or dropping of the soils along the wood bulkhead.
BULKHEAD ROTATING OUT AT BASE
Indications of major imminent disaster are the bottom of wood bulkhead leaning or kicking out at the base. This symptom usually indicates that major soil loss has occurred allowing the wall to kick out. Another cause for this condition is in adequate sheet piling penetration. This a predominate condition throughout southwest Florida where sub-surface rock is located close to the surface. Most contractors installing wood bulkheads did not penetrate the rock with piling and sheeting.
If you elect to ignore any of the revealing signs of bulkhead toe failure, you are putting the golf course property at risk. Coastal Foundation Solutions Repair costs are far less if you initiate remedies early. You will also avoid damage to adjacent structures, such as golf course greens and fairways, not to mention the possibility of catastrophic failure.
The top of the bulkhead usually has a top cap which consist of a 2” x 10” pressure treated top cap to finish off the bulkhead template. This also acts a protection device prohibiting water intrusion into the wood sheeting portion of the bulkhead. Over an extended period of time these timbers tend to rot-out and disintegrate. When this occurs, water intrusion begins, and the lower wood timbers are subjected to deterioration and failure. Placing this wood timber in a fashion to prohibit this from occurring is always overlooked at the initial construction stage (grow rings facing down). Also, landscapers are always adding to the caps demise by constantly chewing away at it with weed eaters.
INSPECTING WOOD PILINGS
Wood piling used in construction of bulkheads have a service life of twenty (20) to twenty-five (25) years before major deterioration sets in. The early signs of complications commencing at the top of the wood piling. Years of rainfall accumulating at the pile top causes water penetration down through the top of pile creating weakening elements. As this erosion continues, the main structural support for the wall is compromised. When one or even a few pilings have decayed the tie rods holding them in place can rip through the wood. The tie-back systems already weak from corrosive properties on supporting ½” cables now also face loss of structural hardware bearing. The galvanized eye bolt attached to the cable tie-back losses its integrity as the piling top starts to rot away. This component configuration makes up the entire support for the bulkhead/wood seawall.
Once this tie-back/deadman system is compromised, the wall is in immediate danger of collapsing.
Coastal Foundation Solutions has the experience and capacity to save the structure from collapse if notified in a timely fashion. Our helical tie-back system has been erected in many emergency bulkhead failure scenarios.
Parts and pieces randomly fall off or become dislodged on golf course bulkheads over time. The most frequently encountered setback is the structural whaler falling off due to fastener being corroded and losing the connection to the vertical wood sheeting. In addition, the 3” x 8” wood whaler timber becomes cracked in the middle due to excessive strain on the timber from hydrostatic pressure on the wall.
The main culprit in this scenario is age and water, plus lack of maintenance. It is imperative that someone investigate the bulkhead structure on an annual basis to prevent failures from occurring.
BULKHEAD REPAIR SOLUTIONS
Coastal Foundation Solutions can repair the bulkhead quickly, costing a fraction of the cost of replacement. Our solutions provide minimum disruption to the course or delays in tee time schedules. The repair solutions can take place on the water side of the wall, consequently with no disruption to the course or greens.
In most cases no digging or impact to the course or greens occurs. Our golf course techniques and repair process will allow the General Manager or Golf Course Superintendent to meet his schedule, insuring no course down time or loss of revenue.
Coastal Foundation Solutions helical anchors are an ideal solution to maintain your vertical alignment on wood golf course bulkheads while protecting your greens and fairways from usual damage caused by traditional repair methods.
Our installation procedure is suitable for the environment and ECO FRIENDLY, no negative impacts to bodies of water occur, because we only USCG approved hydraulic fluids are used, which are totally sheen free.
Should The Wall Be Repaired Or Replaced?
Multiple variables contribute to factors on whether it’s time to replace or repair a bulkhead structure. If sufficient damage and deterioration is evident, the best decision is to consult with a licensed marine contractor. Factors that could influence the decision are:
- Amount of structural damage present
- Cost of seawall repair vs. replacement
- Decision to use different materials
Most wood bulkheads can be structurally repaired rather than replaced. While this may not be a permanent solution, selecting an inexpensive repair, may add years of life to an existing bulkhead. In some circumstances, we have implemented repairs and renovations to walls increasing their longevity by 10 to 15 years.
Southwest Florida wooden bulkheads are a part of golf course living and enjoyment, they protect the property from upland erosion, and they provide aesthetic value to our beautiful courses.
In the content below, we will explore some of the more modern repairs that are commissioned on bulkheads and the extent of these restorations. There are engineered and proven steps to stabilize the wood bulkhead and prevent further lean or collapse of the bulkhead.
Wood decay and degradation creates voids in the planks of a bulkhead, consequently soil can wash out and migrate through the plank seams. The filter cloth material used on most walls was a cheap weed mat and not designed to contain soil. Repairing a few small holes is relatively easy, but once the wall commences loss of soil the problem accelerates.
Capping of a wood bulkhead can be performed to repair a bulkhead which is loaded with voids and holes. The capping process is very effective as long as the pilings and horizontal whalers are structurally sound. The capping process entails placing new 2” x 8” pressure treated wood planks over the existing aged planks. This is done on the exterior (water side) of the bulkhead. A D.O.T. filter fabric is attached over the old existing planks and fastened with stainless steel hardware to prevent future soil loss. The capping planks are screwed and secured into place with # 304 Stainless Steel 3 ½” long screws. This bulkhead repair may gain a wall an additional 18 years of life expectancy.
HELICAL TIE-BACK ANCHORS
The introduction of helical tie-back anchors ushers in a new era in seawall/bulkhead anchor technology. Coastal Foundation Solutions is a premier helical contractor with a plethora of knowledge gathered over the last 28 years in installment of these systems.
What Are The Benefits Of Helical Tie-Back Anchor Systems?
Our “Chance” helical anchors are built extra tough to stringent American standards thereby guaranteeing safe products and consistent quality. The installation procedure allows the anchor pile to be drilled and installed at the same time, offering advantages to tension holding capacities. The type of machinery used for installation is relatively compact and has a very small carbon footprint, dramatically increasing the productivity on site.
Our system is one of the most effective and versatile tie-back anchor engineering solutions available to our clients.
Helical Tie Back anchors can be designed to meet a 100 year service life. This is founded on the systems steel properties and allowances for sacrificial loss of cross section.
We maximize the space provided for our equipment to perform the helical anchor process. Additionally, our company maintains a fleet of various sizes of floating barges with excavators to match.
Traditional approaches of internal propping and shoring of the bulkhead, driving batter piling or excavating holes for concrete are now obsolete.
STRUCTURAL WHALER SUPPORT
Structural Whalers are massive treated wooden crossbeams attached to the piling which will sustain the weight of the wood bulkhead. Nothing less than 4” thick timbers should be used for whalers supports. There is must be adequate whalers to withstand the hydraulic pressure the bulkhead will have to oppose. The whaler is bolted to the piling with a large galvanized timber bolt passing through the whaler and the pile.
We have reinforced failing whalers by attaching new wood or galvanized whalers above or below the existing ones. This process ensures the integrity of the wood bulkhead and prevents further bowing of the sheeting. The supplemental whalers are notched to conform to round pilings and usually have a helical anchor supporting it.
NEW TOP CAP
The top cap timber of the wood bulkhead is a significant timber that adds to the longevity of the structure. While it provides an aesthetic feature, it also stops water from intruding into the end grain of the wall sheeting. This timber is subjected to constant abuse by landscapers who routinely are attacking it with their weed eaters, consequently adding to the deterioration of the timber.
Coastal Foundation Solutions has introduced PVC structural plastic timbers as a replacement for the traditional wood timber. The PVC timber once installed shall be in place long after the existing wood bulkhead fails. The additional cost of the structural plastic while more expensive, outweighs the labor to keep replacing the wood top cap. Our plastic top cap installation is performed using the best product available and attaching everything with stainless steel screws.