Shotcrete vs Gunite: What’s the Difference?

Is gunite just another word for shotcrete, or a different material? The American Shotcrete Association (ASA) answers with one sentence about process, not material. Every source in this article is an ASA page; no DOT or PCA page was read.

Is Gunite the Same as Shotcrete?

Not quite: gunite is one kind of shotcrete. ASA calls shotcrete “an all-inclusive term” for spraying concrete or mortar through either a dry-mix or a wet-mix process. In that same FAQ, ASA says gunite refers only to the dry-mix process.

The page labels follow the same logic. ASA’s About Shotcrete page shows the heading “Dry Mix” with the note “sometimes referred to as Gunite”, and a separate heading, “Wet Mix”. ASA also says shotcrete has often been described not as a material but as a process.

ASA gives no strength figures for either process on the pages read, so none appear here.

How Does Each Process Get the Material to the Wall?

ASA describes two different routes to the nozzle. In wet-mix, all concrete materials, including water, are mixed first and pumped. In dry-mix, the water joins at the nozzle.

For wet-mix, ASA says the wet concrete is pumped to the nozzle, where compressed air is added to place and consolidate it on the receiving surface. ASA adds that the previously prepared mixture is typically ready mixed concrete. Our guide to ready-mix vs bagged concrete covers that starting point.

For dry-mix, ASA says pre-blended dry or damp materials go into the delivery equipment. Compressed air carries them through a hose at high velocity to the nozzle, where water is added. ASA says complete mixing is not possible in the nozzle, so mixing is finished as the material hits the receiving surface, through manipulation of the nozzle.

Once you know the process, the next question is volume. Our shotcrete calculator turns an area and a thickness into a supply volume with a rebound allowance you choose. It does not choose wet or dry.

What Differs Between Wet-Mix and Dry-Mix?

ASA names production, air entrainment, rebound, dust, aggregate and operator skill as points of difference. Most of the contrast comes from one ASA structural FAQ answer, written for a question about a dam. Treat the table as ASA’s statements, not a ranking.

ASA also tempers that contrast. Its About Shotcrete page says rebound levels, dust levels, bond strength, compressive strength and durability can be similar today, whichever method is used. It says advances in materials and equipment make the two processes almost interchangeable.

So the sources do not say one process always wins. ASA says the preferred method is usually set by economics, availability of material and equipment, site access, and the expertise and preference of the contractor. No rebound percentage is given here because none was verified.

Where Did the Word Shotcrete Come From?

ASA says “shotcrete” first appeared in Railroad Age magazine, in place of the then proprietary word “Gunite”. The page says this was more than 50 years ago and gives no year. ASA adds that the American Concrete Institute has used the term since at least 1967 to describe all sprayed concrete or mortar.

In ASA’s definition, the older name now points only at the dry-mix process. This article does not state the legal status of the name, because no source on that was read.

The process itself is old too. ASA’s pools page says swimming pools were first built using shotcrete in the 1930s (ASA pools page, accessed 2026-10-21). The ASA tanks and domes page (accessed 2026-10-21) says tanks have been built since the process was pioneered in the early 1930s. ASA does not say pools or tanks use only one process.

What Is Shotcrete Used For, and Who Should Place It?

ASA’s About Shotcrete page lists seven application areas. The same page calls shotcrete one of the most versatile processes available for concrete in new construction and repairs.

ASA’s own pages add a few details for three of those areas, as the list shows.

• Ground support. ASA says earth and rock excavations are effectively stabilized with shotcrete and a variety of reinforcement and anchoring systems. It also calls shotcrete ideal for ground support in tunneling and mining (ASA ground support page, accessed 2026-10-21).
• Repair and restoration. ASA says shotcrete is often the best alternative when repair and restoration are being contemplated. It says the method can suit both reinforced and nonreinforced construction (ASA repair page, accessed 2026-10-21).
• Pools and skate parks. ASA says shotcrete is especially suited to pools and skate parks with many curves, because it is shot against excavated soil and no forms are needed (same ASA pools page, accessed 2026-10-21).

On who places it, ASA’s Underground FAQ says a qualified shotcrete contractor will use ACI-certified nozzlemen. It says that contractor should provide a resume of similar, successfully installed projects, with current contacts for the owners or engineers involved. The ASA architectural FAQ (accessed 2026-10-21) says ASA does not have certified contractors, though many member contractors have ACI Certified Nozzlemen on their teams.

ASA’s Underground FAQ also covers slopes. It says shotcrete slope paving alone is not generally considered a retaining wall, and that as a retaining structure it is generally done with soil nailing, tie backs or some type of structural footing. For wall limits, see retaining wall height limits.

A Worked Example: From Area to Supply Volume

The sizing arithmetic below uses the tool’s default inputs. It is arithmetic, not a rate from any source: the 10 percent rebound allowance is the tool’s default input, and no ASA page read here gives a rebound figure.

1. Volume in place. The area is 100 sq ft and the thickness is 3 in, which is 3 / 12 = 0.25 ft. So 100 x 0.25 = 25 cu ft.
2. Add the allowance. At the tool’s default 10 percent, multiply by 1.10. So 25 x 1.10 = 27.5 cu ft.
3. Convert to cubic yards. There are 27 cu ft in a cubic yard. So 27.5 / 27 = 1.0185, which rounds to 1.02 cu yd.

Hand-check: 25 x 1.10 is 25 + 2.5, which is 27.5, and 27 x 1.02 is 27.54, so 1.02 cu yd matches. The result is the same whichever process is used, because the sum has no wet or dry input. Related tools sit on the concrete volume and ordering calculators page.

FAQs About Shotcrete and Gunite

Sources and Further Reading

This article reports what the American Shotcrete Association says and is not a specification or mix design. Shotcrete is the whole family and gunite names only the dry-mix process, so ask your contractor which process they will use. Reviewed for accuracy by Prof. Dr. Khalil Mudassar, PhD. Last updated 2026-10-21.