A gunite pool is a pool built in place: an excavated shape, a steel cage, and concrete sprayed over it to form the shell. Because nothing arrives pre-made, the shape, depth, ledges, steps and spa are designed for your lot. This page explains how a gunite pool is built, what to expect on Houston clay, and what to ask any builder before you sign. Astorga builds gunite pools throughout Greater Houston.
What gunite is
Gunite is concrete, sand and water applied by spray over reinforcing steel. It cures into a hard, monolithic structural shell. Pool builders also use the word shotcrete. Both are sprayed concrete; the technical difference is that gunite is mixed dry and water is added at the nozzle, while shotcrete is mixed wet before it is pumped. In everyday pool talk the two words are often used for the same thing, so ask your builder which method they use rather than assuming.
How a gunite pool is built
- Design and engineering. The shape is drawn to your lot, then engineered. On Houston clay the structural plan is designed per site, not copied from a catalog. The design decisions are listed in order on our custom pools page.
- Permits and HOA review. Approvals run on municipal and association calendars. Who approves what depends on where you live.
- Excavation. The hole is dug to the design depth. Where the water table is high, dewatering is planned in advance.
- Steel and plumbing. A rebar cage defines the shell. Plumbing, drains and electrical bonding are set before any concrete goes on.
- Shell. Concrete is sprayed over the steel and shaped. The shell then has to cure before the next stage continues.
- Tile, coping and decking. The waterline tile, the pool edge and the deck are built around the cured shell.
- Interior finish. Plaster, pebble or another finish goes on the shell and also has to cure before the pool is used.
- Fill and start-up. Equipment is commissioned and water chemistry is balanced before swimming.
Two stages are fixed waits no matter who builds: the shell cure and the interior finish cure. How long a project takes overall depends on design revisions, permits, weather and how quickly selections are made. We do not quote a guaranteed duration; here is what drives the calendar, and our six-phase process shows what you decide at each step.
Why gunite suits Houston
Much of Greater Houston sits on expansive clay that shrinks when dry and swells when wet. A gunite shell is engineered for the soil your site actually has, with steel and thickness designed for that movement. Decks need the same attention: slope, drains and joints are design decisions on clay. Pool construction on Houston clay walks through the soil data with sources.
Gunite also lets features build as one structure: raised walls, spillover spas, tanning ledges and benches. If a smaller footprint is the goal, see small and plunge pools.
Gunite or fiberglass
Fiberglass has real advantages, mainly speed and a smooth surface from day one. It is limited to factory shapes and to what a truck and crane can deliver to your backyard. Gunite takes more decisions and more patience and gives a pool drawn for your yard. The full tradeoff is in our gunite vs. fiberglass comparison, and if a catalog shell fits your lot and budget better, we will say so at the consultation.
Finishes, features and salt systems
The shell is only structure. The interior finish, tile, coping, lighting and equipment decide how the pool looks and how it is maintained. Finishes renew over time without rebuilding the shell, which is one reason gunite is treated as the long-term structure.
We install salt systems. A salt system generates chlorine from salt in the water rather than relying on added chlorine alone, so the pool still needs regular testing and balanced water. Salt can also be harder on some natural stone and metal fittings, so material choices for coping, decking and equipment should be made with the water system in mind. Ask us about it during design, not after the shell is poured.
What a gunite pool costs in Houston
Cost depends on size, shape, site conditions, access, equipment and finishes. We publish current Houston ranges, our own starting prices and what is and is not included on what a pool costs in Houston, and the questions to ask are in what a pool quote should include.
Questions to ask any gunite builder
- Who engineers the structure for my soil, and can I see the plan before I sign?
- Is the shell gunite or shotcrete, and how long is the cure before work continues?
- What is in the price, and what is excluded (deck, fencing, electrical, permits)?
- Where does water drain from the deck and roof, and what happens in a heavy rain?
- What finish do you recommend for my use, and what is its maintenance?
- Who is my single point of contact from contract to start-up?
Common questions
Is a gunite pool the same as a concrete pool?
Yes, in practice. The shell is sprayed concrete over a steel cage. Gunite is the method; concrete is the material. Builders also say shotcrete, which is concrete mixed wet before it is pumped rather than dry-mixed and wetted at the nozzle. Ask which method your builder uses rather than assuming.
What is the difference between gunite and shotcrete?
Both are sprayed concrete over reinforcing steel, and both produce the same kind of custom, built-in-place shell. Gunite is mixed dry and the water is added at the nozzle; shotcrete is mixed wet before it is pumped. In everyday pool talk the words are used for the same thing. What matters more than the word is the engineering behind the shell and the cure time your builder holds to before work continues.
Can a gunite pool have a salt system?
Yes. We install salt systems. A salt system generates chlorine from salt in the water, so the pool still needs regular testing and balanced water. Salt can be harder on some natural stone and metal fittings, so coping, decking and equipment should be chosen with the water system in mind, during design rather than after the shell is in.
Does a gunite pool crack on Houston clay?
Cracking is a design and drainage question more than a material one. Much of Greater Houston sits on expansive clay that moves with the seasons, so the shell is engineered per site, with steel and thickness designed for that movement, and the deck gets slope, drains and joints drawn for clay. Pool construction on Houston clay walks through the soil data with sources.
How long does a gunite pool last in Houston?
The shell is built to be generational: a steel-reinforced concrete structure engineered, on Houston clay, for seasonal soil movement. What wears is the interior finish and the equipment. Plaster typically needs renewing after roughly a decade of Houston sun and water chemistry; pebble and aggregate finishes go longer. Pumps, heaters, and automation are replaced on their own cycles. A well-built shell with its finish renewed on schedule is the pool the next owner inherits, which is what pool remodeling and restoration is for when a pool reaches that point.
Why gunite instead of fiberglass?
Gunite (concrete) pools are built in place, so shape, depth, ledges, and spas are fully custom, and they handle Houston’s expansive clay soils well when properly engineered. Fiberglass shells install faster but come in fixed shapes and sizes. We build gunite because our work is custom design.
We build gunite pools across Greater Houston; where we build lists each area with its permit path and soil.
Talk to us about your lot.
Every Astorga project starts with an in-person consultation and site visit, then a written proposal. We will tell you plainly what the yard can take and what the shell needs on your ground.
Prefer to ask a question first? Use the contact page.