Thanks for your response. I just wonder why it would be in a contract if it's not what they use, technically. Oh well, I guess it doesn't really matter at this point. I was just curious as to what you guys would think. Thanks!

The terms are used interchangeably by many in the industry. I like to specify that we spray shotcrete but that term is often met with blank stares, while the word gunite receives knowing nods LOL

A&S just switched over to shotcrete here in Charlotte. Maybe your company did the same.

Good point, Cascade. I've never heard anyone say "I have a Shotcrete Pool" :)

I believe for the most part, shotcrete is superior due to the fact that it's premixed and doesn't rely on the applicator being at the top of his game. I wouldn't be concerned.

Our pool is shotcrete, btw.

http://theaustindude.blogspot.com/

Here is a link that might be useful: our shotcrete pool build

According to the American Shotcrete Association:

Question 1: What is the difference between shotcrete and Gunite?

Answer: Shotcrete is an all-inclusive term to describe the spraying of concrete or mortar that may be accomplished through either a dry- or wet-mix process. Gunite refers only to the dry-mix process in which the dry cementitious mixture is blown through a hose to the nozzle, where the water is injected immediately prior to application. Because complete mixing of the water and dry ingredients is not possible in the nozzle, mixing is completed as the material impinges on the receiving surface, through manipulation of the nozzle. This requires a very highly skilled nozzleman, especially in the case of thick or heavily reinforced sections. Large aggregate is seldom used with the dry-mix process. Wet-mix shotcrete involves pumping of a previously prepared mixture, typically ready mixed concrete, to the nozzle. Compressed air is introduced at the nozzle to impel the mixture onto the receiving surface. The mixture usually contains minus 1/2 in. aggregate, although larger-size aggregate has also been used.

The use of the term "shotcrete" first occurred in Railroad Age magazine more than 50 years ago in place of the then proprietary word "Gunite," and has been used by the American Concrete Institute since at least 1967 to describe all sprayed concrete or mortar.

Here is a link that might be useful: FAQS

Thanks guys! You all are very knowledgable. I'm not really concerned, as I've read Shotcrete was superior to Gunite anyway, it was just the technicality in the contract. It may sound petty, but PB has gone back to the contract several times to justify ridiculous charges that did not exist until after an argument last week. All of a sudden I owe thousands extra from the dig 2 months ago. Thanks for your responses!

Shotcrete is superior to Gunite? I assume you read that from the shotcrete institute. They both have their positives and negatives. Anytime you add water to concrete it weakens it. Shotcrete can actually be weaker than gunite due to this. You might want to read other opinions other than from the shotcrete institute.

The ASA supports both wet and dry methods and as far as I know they do not recommend one over the other for pools. For other applications, there may be a preference.

However, I have heard that Gunite (dry Shotcrete) is a stronger than wet Shotcrete for the reasons Devildog mentioned above. I have also heard that Gunite is harder to apply correctly because it is mixed at the nozzle and it requires a well experienced nozzleman to get the correct mix for strength. This may be why there are fewer companies providing Gunite. Here is what the ASA says about the difference:

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Question 45: As a specifier, should I specify which processÂdry or wetÂshould be used on my projects? What are the significant differences?

Answer: The application of shotcrete can be done successfully with either method. The dry-mix shotcrete process tends to be more favorable for lower volume placements. It is also a more flexible method, allowing for more frequent relocations of equipment. Equipment is more easily cleaned at the end of the placement. The nozzleman must exercise great care in adding the necessary amount of water while shooting.

The wet-mix shotcrete method is more favorable for larger volume placements. Rebound is substantially less than in the dry-mix shotcrete process. The nozzleman does not have to be concerned with controlling the water addition. This method is less efficient when there is a requirement for frequently starting and stopping placements. The wet shotcrete mixture has a limited "pot-life."

Remember, shotcrete is not a special product. It is a method of placing concrete. All the recommended practices for concrete placed by any other method, such as curing and protection, also apply to shotcrete.

Mas985, thanks for your response, and Devildawg, didn't mean to step on anyone's toes. After reading about the two, instead of superior I should have said easier. My crew had a hard enough time with the shotcrete. If they were responsible for mixing it, too, who knows what would have happened. Gunite pool owners please forgive me!

Shotcrete is only as good as the plant mixes... consider travel time from plant and size of pool...friction and evaporation loss..... as the mix gets sticky the only thing the operator can do is dilute it.... Gunite on the other hand is mixed to the current conditions every time.. either one PROPERLY applied can last forever.... in my area there are more Shocrete builders for the simple fact that is costs less to shoot and costs less to get in the business if they choose to shoot themselves...

I went with the wet-mix shotcrete and we requested a specific local supplier to our builder that we thought would supply a good mix.

However, I realized that the type of shotcrete (wet-or- dry) was only one factor in the pool shell construction process to consider, others being: the wall & floor thickness, the grade, size and spacing of the rebar, the depth of the bond beam, the skill of the various construction crews, soil conditions, the pool engineering design and more.

If you follow this link there are some good articles that may be helpful regarding the proper application of shotcrete and pros and cons of the wet & dry products.

http://www.pooleng.com/Shotcrete---Gunite/ca-24.aspx

I'd be happier with shotcrete, as it is more thoroughly mixed throughout, and removes 'operator error' sometimes experienced at the nozzle end of gunite applications. Shotcrete will provide a more uniform strength, with minimal opportunity for errors.

Shotcrete over Gunite. My test is called the pick axe test. Take a pick axe and see which one your going to stick in or bounce off. That simple

Shotcrete is premixed as indicated by many her e- the importance of having a ready mix company control the water ratio by use of plasticisers can not be understated. With gunite the moisture control is through the nozzle operator - and let me tell you when you are on a nozzle then you have your hands full already. The potential for compromised concrete due to over-inundation with water at the nozzle is quite possible with gunite - much less so with shotcrete.

Shotcrete and gunite are genuinely interchangable in the industry and I am certain that your builder is switching these terms innocently since almost everybody calls concrete pools gunite pools - when in fact there are many different types of concrete pools like cast and shotcrete. If he says shotcrete you might choose another builder who said gunite - when in fact they are both selling you the same thing...usually shotcrete. This is of course regionally dependant but shotcrete pools outnumber true gunite pools in North America by orders of magnitude.