Coastal construction projects face engineering challenges not typically experienced by those building inland. Shifting sands tend to weaken foundations, and the constant salt exposure accelerates material deterioration. Five key challenges arise for structures in locations exposed to saltwater.
Table of Contents
1. Foundation Damage From Coastal Scour
Storm surge-induced bed scour threatens building foundations in coastal zones. During a storm, powerful waves and surging water strip soil and sediment away from a structure’s base. This erosion usually starts at the front corners and spreads, weakening the foundation.
Scouring also increases water velocity near the base, which amplifies the wave force on the structure. Builders address this threat by installing deep foundations and specialized pilings that can remain stable even when scour removes the surrounding soil.
Waves and tides alter the coastal landscape throughout seasonal cycles and storm events. Builders must account for these ongoing conditions when designing foundations that will last for decades.
2. Corrosion of Equipment and Materials
Saltwater and saline air create highly corrosive conditions for metal components used in construction equipment and building materials. Equipment corrosion degrades structural integrity and requires frequent tool and machinery replacement — a high cost in terms of time and resources.
Corrosion protection can be achieved by galvanizing components with a zinc coating. Wire ropes and other metal components are protected from saltwater damage through this process. By employing various protective measures, construction teams can prevent metal corrosion, extend equipment lifespan and maintain structural safety.
Building materials are subject to the same constant exposure to salty air that threatens equipment. That said, specialized and durable materials, such as stainless steel and marine-grade aluminum, become necessary. High-grade treated timber and corrosion-resistant fasteners also serve critical functions in coastal building assemblies.
Standard materials that perform well inland often fail prematurely in coastal applications, making material selection a critical planning consideration that affects initial costs and long-term maintenance requirements.
3. High-Velocity Wind Loads
Tropical storms, nor’easters and persistent onshore breezes can create continuous stress on structures, eventually leading to their decline. High winds push and pull on buildings simultaneously, and these eventually cause stress on every structural element.
The building envelope usually fails first, as roofing, walls, windows and doors take direct hits from wind and flying debris. Coastal projects need wind-resistant and wind-driven water-resistant envelopes that can hold up during storms.
Engineers must calculate wind loads specific to their target coastal location when designing structural frames and selecting exterior materials. These estimates should consider the presence of sustained winds and wind gusts in the area, plus the compounding effects of saltwater sprays that can degrade protective coatings over time.
4. Humidity and Mold Growth
Coastal air stays humid all year round, and this can threaten building materials and indoor air quality. Moisture constantly penetrates components and creates ideal conditions for mold growth.
As mold needs only moisture and oxygen to thrive, it can grow on almost any organic substance, including wood, paper, carpet and insulation. The dust commonly found in buildings provides sufficient nutrients from paper particles and skin cells, allowing mold to establish itself wherever moisture accumulates.
Coastal structures require proper ventilation and dehumidification systems to prevent mold growth. Vapor barriers and moisture-resistant building materials provide extra protection against humidity infiltration. Equipment corrosion also relates to humidity issues, as moisture in the air accelerates the oxidation of metal surfaces, even without direct water contact. Builders must integrate moisture management strategies as early as the design phase to avoid costly remediations after construction is complete.
5. Complex Coastal Building Regulations
Coastal zones must comply with local, state and federal requirements, which often overlap. Agencies regulate coastal construction heavily to account for hurricane winds, storm surge, saltwater corrosion and long-term erosion patterns. Project teams need to budget ample time for permits and make sure everyone understands the rules before construction starts.
The Federal Emergency Management Agency’s (FEMA) start of construction date marks a critical permitting milestone. This date determines which regulatory requirements and building codes apply to a project.
Environmental regulations add another layer of complexity to coastal projects. FEMA standards control where and how teams can build by limiting building footprints, restricting changes to natural features such as dunes and shorelines, and setting specific site-selection criteria.
For example, Florida’s Coastal Construction Control Line Program sets a boundary along the coast where builders must meet stricter siting and design rules to protect beaches, dunes and public use. At the federal level, the Coastal Barrier Resources Act discourages any development on designated coastal barriers by prohibiting most expenditures and financial assistance within the Coastal Barrier Resources System, which spans 3.5 million acres across 23 states and territories.
Remote locations with limited road access also make material transport difficult, and environmental protection zones can prohibit certain construction methods entirely.
Final Considerations for Coastal Construction
Shoreline construction must address foundations, corrosion, wind forces, moisture and regulations from the very beginning. Projects that account for these factors as early as the design phases will meet the durability and safety standards that coastal conditions demand.
