Difference Between Gunite, Concrete, & Shotcrete in Swimming Pool Construction

model house poolGunite, concrete, and shotcrete are basically the same thing with variations in inherent water-tightness, strength, and construction methods. People throwing around these terms so carelessly must know that they are just different types of concrete with unique weaknesses and strengths.

Concrete can be considered as a man-made strong rock. There have been many forms of concrete since the Assyrian times and the Romans made huge strides in constructing some structures out of crude effective concrete forms. The different types of concrete come from differences in the specific formulas used by engineers while designing these structures. Admixture chemicals, water, aggregate and cement are part of every concrete formula. The quality of a swimming pool will have to do with the strength and water-tigthness of the concrete used in the construction. Now that you know something about concrete, we are going to talk about the differences between cast-in-place concrete, gunite and shotcrete.

Cast-In-Place Concrete

A form is built using wooden boards. Then workers pour runny and wet concrete mixture into this mold before smoothing out its surface. Then this concrete will dry hardening into this structure. Walls, floors and decks are the typical concrete structures comprising any aquatic facility. Many contractors and designers use the cast-in-place methods because of its ease of use. To control cracking in any concrete structure, designers use joints between concrete sections of any pool. The reason for this is that tons of water is lost in this process.

Cast-in-place concrete system may be considered as straightforward systems. Workers will place steel reinforcement and fresh concrete on temporary molds. A ready mix supplier may deliver ready mixed concrete to any location, though workers can also batch concrete on site. Steel, wood and aluminum are the most commonly used formwork materials to cast concrete. Aluminum and steel forming systems allow for saving on costs as they are designed to be used multiple times.

Cast-in-place concrete produces very strong walls resistant to disaster. In addition to this, this type of material is resistant to mildew, rot and mold having sound-blocking ability. Constructors tend to like cast-in-place concrete due to their familiarity with this type of material and its cost-effective technology. Remember that most contractors have been using this type of material for quite some time, and they might prefer to use it for the construction of swimming pools. However, make sure that this type of technology is part of a group of technologies used for the construction of your swimming pool.

Pools must have joints properly designed so that they can become waterpoof in every possible way. Proper maintenance must also be given to every joint so that the swimming pool can remain waterproof. Any joint may become a source of water loss if it is not well constructed or designed.

Pros

– Most contractors have experience with this type of concrete. Remember that this is the most used type of concrete.
– The structure can be waterproof and strong if designed properly.
– You can also expect to get a smooth surface if this material is properly designed which allows for the use of epoxy based pool painting systems.

Cons

– The pool sections might have problems.
– It is the weakest of the three methods.

Shotcrete Concrete

Shotcrete concrete allows designers to create watertight and strong structures. Shotcrete concrete can also be used to form any underside of a ceiling as well.

Shotcrete systems are durable, strong, resistant to fires, insects and vermin, mold, disasters, and have good thermal mass, low permeability, and create tight envelopes. Shotcrete’s hardness is similar to cast-in-place concrete, but the nature of shotcrete’s placement provides further benefits such as fast erection which is particularly true on complex shapes or forms including archs and curved walls. Because of its minimal equipment requirements and speed of construction, shotcrete is a cost-effective building method.

There are 2 main types of walls that can be made with shotcrete: plain uninsulated walls and sandwich insulated panel systems. The latter are made of polystyrene insulation’s prefabricated panels put into two wire mesh’s parallel sheets. Galvanized welded wire is used to connect those two faces of mesh piercing the insulating at acute angles in order to create a truss-like, strong support system. Depending on the concrete layers and core insulation, these walls may achieve R-values from seven to thirty three. This concrete can also provide thermal mass benefits.

Shotcrete systems’ wall forms are lightweight, and this is the reason why these systems can be installed so quickly. Since they are very easy to handle and make, workers can erect the shape of any construction in a straightforward way. In addition to this, workers will avoid using tons of equipment. Panels tend to brace each other once connected before shotcrete hold them together. Shotcrete methods require pouring materials onto the mold.

Pros

– Shotcrete can make the most watertight and strongest concrete pool possible if well constructed and designed.
– Fewer joints will be found in the pool.

Cons

– The finish tends to be a little bit rougher than that of cast-in-place concrete.

Gunite

Gunite is a type of concrete applied pneumatically to any surface. Gunite is also used in many vertical surfaces like pool walls. Workers do not use any water to apply gunite to a surface until the actual moment of the application using a gunite nozzle.

Pros

– Gunite can make the most watertight and strongest concrete pool possible if well constructed and designed.
– Fewer joints will be found in the pool.
– Higher compressive strengths than shotcrete and cast-in-place concrete.

Cons

– The construction process tends to be more time consuming than shotcrete.
– Fewer people are skilled in using this type of concrete.

We are proud to say that we use gunite for all our inground pool constructions.

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