When a contractor talks about building a gunite swimming pool, don't let the terminology throw you off. Gunite refers to the method in which the contractor mixes the concrete compound used to form the shell of the pool. The process of constructing a gunite pool does not really differ from that of constructing any other in-ground concrete pool. Educate yourself on the pool-building process; learn the basics of gunite, its application and the best practices for building an in-ground pool.
The only difference between gunite and shotcrete---the two most popular choices of concrete used for in-ground pools---involves their use on the site of the pool project. Both comprise a mixture of cement, sand and water. The contractor will mix shotcrete before bringing it to the site and then mix it again with air when while spraying it through a hose onto the walls of the pool. Gunite, on the other hand, is a dry mixture that the contractor will mix with water and air while spraying it in place. Contractors have made gunite a popular choice due to its ease and quickness of use, along with the possibility of mixing it right on site,
Excavation and Preparation
Before starting any pool installation, check with your local municipality to find out whether you need to pull a building permit. Then begin planning the dimensions and location for your pool.
To dig the hole for the pool, you will need heavy earth moving machinery, such as a backhoe or gravel hauler. Lay out the perimeter of the pool with stakes, or outline the area on the ground with lime.
After staking out the site, break ground and dig to the desired depth. The excavation makes up a very important part of the construction process for concrete pools, as you'll need to make the dimensions precise. With this in mind, initially fill the hole to make it 6 to 12 inches smaller than what will become the actual size of the pool. Later, you will use hand tools to carve out the exact shape, preventing the difficult process of backfilling the hole if you make it too large. By using hand tools, you will shape the walls and get rid of any rocks or debris.
To give the in-ground pool more strength and durability, reinforcement rods need to be put in place. These rods, called rebar, look like steel fencing and are added all the way around the inside of the pool. These are later sprayed with the concrete.
After the rebar is in place, the mechanical systems are installed. These systems include all of the plumbing for the pump and filter, any electrical systems for lights or a heater. The piping needs to be put in place, fitted through the rebar and brought to the surface.
Spraying the Concrete
Finally, pump the gunite will through a hose and spray it over the rebar. First spray the concrete over the bottom of the pool and smooth it out with a trowel. After the bottom has dried, spray the concrete over the rods on the walls. Again, use a trowel to give the walls shape. Make the walls somewhere between 6 and 9 inches thick, which will require you to add another layer of concrete later.
Installed coping last along the edges of the pool. This material will create a transition from the inside of the pool to the outside.