Three of the most commonly used construction materials in Australia are wood, concrete and steel. Coincidentally, piling comes in these three materials. A pile is essentially a heavy column or section of a strong construction material that is driven deep into the soil or ground to provide a steady support for the foundations of structures put up on top of it.
If you are planning to construct your new residential or commercial building on a piled foundation, you should first learn about the three types of piling, so you can make an informed decision on what type of piling is best for your construction project.
Wood is the traditional choice of material for making piling. Wood piles are basically wood posts made from trees that have exceptionally straight trunks. These piles are mostly round in shape because trees are cylindrical objects. The length of a wood pile is restricted to the length of the tree from which it is made. There's no way one wooden post can be joined to another without compromising on the overall strength of the piling.
Because wood is susceptible to moisture damage, wood piling is normally pre-treated with waterborne preservatives to minimise such damage. Wood piles can be capped with wood, concrete, steel or stone. If the capping is done with timber, the cap should permanently remain below the lowest water mark. The best thing with wood piles is that they can be cut easily, allowing for modifications as needed onsite.
Concrete piles are concrete columns that are made offsite and transported to the project site for installation. Unlike with wood piles, these piles can be tailored to come in different lengths and diameters. This makes them ideal for use in a wide range of building construction and civil engineering projects. Factory-based production means precast concrete piles can be made to tolerate high loadings. Concrete piles are usually top-driven deep into the ground by hammering with hydraulic drop hammers.
Because of the inherent strength of steel, steel piles are used to take on very heavy loads. A variety of steel sections, including tubes, universal columns (commonly referred to as H piles) and quadrangular hollow sections, can be used to make the piles. A combination of two or more steel sections can be used when driving the piling deep into the soil. Where corrosion is an issue, a superior grade of steel than otherwise required should be adopted. Applying protective coating onto the steel may not be an effective solution as the coating can get scraped off as the piles are being pushed into the ground.