Gunite versus Shotcrete

First we need to define both and identify common misunderstandings.

Gunite for Swimming Pools

As described here is a dry mixture of sand and cement (grout) that is pneumatically projected for the purposes of building a gunite swimming pool.

Shotcrete for Swimming Pools

As described here is a wet "or" dry mixture of sand, aggregate, and cement (concrete) that is pneumatically projected for the purposes of building a shotcrete swimming pool.

Misconceptions

Many people believe that all dry mix applications are gunite.

Shotcrete can be applied from a wet mix or from a dry mix.

Many people believe that gunite ( grout) is as strong as shotcrete (concrete).

A mixture of sand and cement without aggregate is mortar or grout. To make that mix stronger aggregate (gravel) is added. The mortar mix becomes concrete when the aggregate is added. Mortar is just not as strong as concrete. This why you will not see a mortar driveway. The weight of vehicles would eventually destroy the weaker mix. The aggregate binds and locks up the mix.

Shotcrete: Wet or Dry?

Each has its own advantages and disadvantages.

The wet mix requires less equipment to apply and a substantially less powerful compressor can be used. The wet mix is subject to the use of "hot loads". Hot loads are concrete that has been sitting in the mixer too long. The cement begins to set so the operator adds more and more water to stop it from curing. The addition of water to a concrete mix severely weakens the concrete.

The dry mix water ratio can be tuned instantly at the nozzle. This allows the least possible amount of water to be added to the mix which increases the strength of the shotcrete. If the nozzle operator, nozzle man, applies the mix with too little water rebound is produced. Rebound is dry mix that didn't get the water needed to bond. The rebound is thrown out of the swimming pool and discarded which can lead to additional materials being used.

What I should know?

If you can afford it, go with shotcrete, All of the features of your swimming pool are applied and tied to the swimming pool shell. If it fails, all of the features can be affected. This is why many of the original gunite companies won't do gunite applications at all. They do shotcrete only. They still have the same names like 'ABC Gunite', but they refuse to use anything but shotcrete.

Swimming Pool Information Pages

Vanishing Edge Swimming Pools

Salt Swimming Pools

Swimming Pool Automation

Swimming Pool Coping Choices

Swimming Pool Remodels

Swimming Pool Grottos and Caves

Shotcrete versus Gunite?