Because of the soil conditions on the coast, typical strip foundations are often not effective at offering the support needed for a house. Due to this and other factors such as extreme coastal weather, beach houses often require pile foundations to create sufficient support for the structure.
Pilings in areas away from the coast can reach supportive bedrock at around eight feet. However, on the coast, sufficiently stable support is usually reached at a minimum of sixteen feet. In some areas such as Florida, piles may need to be driven to thirty feet to create a stable structure.
There are many factors that determine the depth of piles for a beach house, and the installation of these highly important elements will always require professional input. In order to ensure the best structural support for your house, make sure that the proper investigations are done to establish the correct depth for your pilings.
How Deep Are Pilings On A Beach House?
Pile foundations are typically driven to a minimum depth of 8 feet. This differs drastically on the coast, with 16 feet of depth generally required. Piles should be driven below scour depth, with the building above flood levels (bear in mind the need to accommodate for waves).
The scour depth can sometimes be between 10 and 20 feet, meaning that the piles will need to be driven further than this depth in order to anchor the support structure.
In the Florida panhandle area, the scour can be deeper than 20 feet due to subsurface conditions, with the result that piles in coastal residential projects have to be driven between 20 and 35 feet below grade.
Pile Foundations
A piling foundation is one of the best foundation options for a seaside property. Individual supports are pushed into the ground until they reach a stable bedrock support layer.
This allows the house to withstand flooding and storms while also providing a solid support structure in less-than-ideal soil conditions, such as those found in sandy coastal areas.
Pile foundations enable structures to be built in such a way that floodwaters cannot enter and cause damage.
Pilings are placed in the ground by injecting water, which is subsequently held in place by the pressure of the surrounding sand.
8″ by 8″ pilings are buried a minimum of 8 feet deep and up to 16 feet deep for projects near the sea.
Another advantage of homes built on piles is that they can be moved if they have settling or erosion issues. This is a relatively simple process, and these homes can be elevated or reset as needed. The house can even be put into a vehicle and transferred to a new location if necessary.
How To Install Pilings
In order to install pilings, there are numerous processes to go through before construction can begin. Firstly, you will need to obtain a building permit. This can be achieved through contacting your local government and enquiring about the existing building codes and requirements in your jurisdiction.
The next step is to clear the area where the pilings are to be installed and to level the lot. A flat plot of land is required in order for the pile-driving crane to perform its job. Next, you will need to place stakes along the perimeter and corners of the area. This will assist you in knowing where the piles will need to be driven.
You will need to contact your supplier in order to choose the type of piling and its material. The options include piles made of steel, concrete, timber, and fiberglass. Different regions tend to have different preferences for materials.
The best length of piling will need to be verified. This will help to ensure that the correct depth of piling is achieved that will resist any uplift in a vertical direction as well as horizontal loads. The correct length of piling will ensure that no issues are encountered regarding flood elevations, grade elevation, and the potential for erosion.
Once the criteria for embedded depth have been satisfied, the piles can be driven into the ground.
Types of Pilings
Timber pilings have been employed in coastal construction projects for many years. They’re ideal for wet environments and soils with a lot of loose particles. Most construction standards mandate that buildings in flood zones, such as coastal areas, be elevated above the floor level.
Due to the exposure to harsh conditions and the need for a stable foundation to keep the building intact, the pilings become the most structurally crucial aspect of the construction process.
Despite their numerous benefits, pile foundations are more expensive and take significantly longer to build than conventional foundations.
There are numerous varieties of pilings used in coastal construction projects, each with its own set of benefits and drawbacks depending on whether they are made of concrete or wood.
Square and circular timber pilings made of southern yellow pine have a good strength-to-cost ratio. This sort of wood can also be treated in a variety of ways, allowing it to be used in a wide range of applications.
Polymer-coated pilings are timber pilings that have been wrapped in a protective polymer membrane that adheres to the wood. This polymer barrier guards against wood borers, dry rot, and termites, all of which can cause harm if the wood is not sufficiently protected. The polymer layer also shields the skin from harmful UV rays as well as the effects of cold weather.
Solid pilings with a uniform diameter along their length are commonly used for gun barrel pilings. This piling style offers the benefit of combining the strength of round pilings with the uniformity of square pilings.
When it comes to water, rifle barrel pilings are ideal because water is able to flow more quickly and smoothly around the pilings, resulting in less damage to the structure.
Another advantage of gun barrel pilings is that they keep marine borers and termites at bay. This is due to the absence of exposed heartwood.
Conclusion
While pilings in areas away from the coast can meet requirements at only eight feet deep, coastal areas will often require piles that are driven to a depth of up to 30 feet. This is all dependent on soil conditions and the depth at which sufficient support can be achieved.
Sources
- https://www.eng-tips.com/viewthread.cfm?qid=427458
- https://www.ehow.com/how_7891751_install-piling-beach-house.html
- https://askinglot.com/how-deep-are-beach-house-pilings
- https://buildingproductsplus.com/beach-home-materials/
