Swimming Pool and Spa Construction: Shotcrete, Plumbing, Electrical, and Deck Finishing | Projul

Pool construction is one of those trades where you are working with structural concrete, plumbing, electrical, gas, tile, stone, and landscaping all on the same project. Every system interacts with every other system, and the sequencing has to be right or you are tearing things apart to fix problems that should have been prevented.

Whether you are a pool builder refining your process or a GC adding pool construction to your services, this guide walks through the major phases and the details that matter.

Pre-Construction Planning

Site Evaluation

Before you draw a single line on the plan, evaluate the site:

• Soil conditions: Expansive clay, high water table, rock, or fill all affect the pool design and construction approach. A soils report is not optional for most jurisdictions and should not be skipped even where it is not required.
• Access: Can your excavator, shotcrete truck, and material deliveries reach the pool location? Tight backyards with narrow side gates are common and require planning.
• Utilities: Locate all underground utilities (gas, electric, water, sewer, telecom) before excavation. Call 811 and verify with the homeowner about any private lines (irrigation, landscape lighting, septic).
• Setbacks: Check local zoning for setback requirements from property lines, structures, easements, and septic systems. These vary widely by jurisdiction.
• Drainage: Where does surface water go now, and where will it go after the pool is built? Grading and drainage plans must account for the pool deck area displacing permeable ground.

Permits and Engineering

Pool construction requires permits in virtually every jurisdiction. Typical requirements include:

• Building permit for the pool structure
• Electrical permit for pool equipment, lighting, and bonding
• Plumbing permit for water supply, drain connections, and gas lines (if applicable)
• Fence/barrier permit for pool safety enclosure
• Engineering stamped plans (structural and sometimes civil)

Some jurisdictions also require separate permits for the pool deck, retaining walls, and gas-fired heaters. Get your permit list early and submit applications before excavation starts.

Excavation

Excavation sets the stage for everything that follows. Get it wrong and every subsequent trade suffers.

Equipment

Most residential pool excavations use a compact excavator (5 to 8 ton) for the main dig and a mini excavator or skid steer for tight areas. Dump trucks or transfer trucks haul the spoil. Soil volume from a typical 15x30-foot pool runs 75 to 120 cubic yards, depending on depth and shape.

Excavation Steps

1. Layout: Stake the pool outline based on the plan. Verify setbacks and confirm the location with the homeowner before digging.
2. Over-dig: Excavate 6 to 12 inches beyond the pool shell dimensions on all sides to allow room for the plumbing, rebar, and shotcrete application.
3. Shape the contours: Cut the hopper bottom, benches, steps, and spa seat profiles to rough grade. These will be refined during the forming and steel phase.
4. Check elevations: Shoot grades throughout the excavation to confirm depths match the plan. A rotary laser or GPS machine control keeps things accurate.
5. Dewater if needed: High water table conditions may require dewatering pumps running continuously until the shell is complete and heavy enough to resist uplift.

Rock and Difficult Soil

Hitting rock during excavation adds cost and time. Options include:

• Hoe-ram (hydraulic breaker): Mounted on the excavator, effective for soft to medium rock
• Pneumatic rock drill and splitting: For harder rock formations
• Blasting: Rarely used in residential settings due to vibration and liability concerns

Budget a rock contingency in your estimate. If the soils report shows rock at or near pool depth, price it in from the start rather than surprising the homeowner with a change order.

Steel (Rebar) Installation

The rebar cage is the structural skeleton of the pool shell. This phase is where the pool takes its final shape.

Rebar Specifications

Most residential pools use:

• #3 rebar (3/8-inch diameter) at 12-inch spacing in both directions for walls and floor
• #4 rebar (1/2-inch diameter) for beam sections, cantilevered areas, and raised bond beams
• Overlap/splice length: 24 inches minimum (40 bar diameters for #3)
• Chair supports: Hold the steel at proper position within the shell (typically 1.5 to 2 inches from the soil side)

Key Details

• Beam: The pool perimeter beam (bond beam) ties the top of the walls together and anchors the coping. It is typically 8 to 12 inches square with #4 rebar, two bars top and two bottom, with #3 stirrups at 12-inch spacing.
• Steps and benches: Form these with rebar and shape them during the steel phase. Step riser height should be consistent (typically 10 to 12 inches) and tread depth adequate for comfort.
• Spa tie-in: Where the spa connects to the pool, the spillway or connection wall needs proper steel continuity. This is a high-stress area that cracks if the rebar is not detailed correctly.
• Plumbing stub-ups: Coordinate rebar placement with plumbing penetrations. The steel crew needs to know where every pipe enters the shell.

Inspection

Most jurisdictions require a rebar inspection before shotcrete. The inspector checks bar sizes, spacing, coverage, lap splices, and beam reinforcement. Do not schedule your shotcrete crew until the inspection passes.

Plumbing

Pool plumbing runs between the pool shell and the equipment pad. Getting the pipe routing, sizing, and connections right during this phase prevents problems that are extremely expensive to fix after the shell is shot.

Suction Side

• Skimmers: Typically 2-inch PVC from each skimmer to the pump. Most residential pools have two skimmers. The skimmer bodies are set during the steel phase and must be at the correct elevation for the waterline tile.
• Main drain: 2-inch PVC from the main drain to the pump. Current code (VGB Act) requires two main drains per pool, spaced at least 3 feet apart, connected with a split line. Single main drains are no longer compliant.
• Spa suction: Separate suction line from the spa to allow independent spa operation.

Return Side

• Return inlets: 1.5-inch or 2-inch PVC from the filter/heater back to the pool. Place returns to create proper circulation, typically pointing down and toward the skimmers to create a circular flow pattern.
• Spa returns: Separate returns for the spa, including jet fittings for hydrotherapy.
• Water features: Dedicated return lines for waterfalls, deck jets, bubblers, and other features. Size these for the specific flow requirements of each feature.

Equipment Pad Plumbing

The equipment pad is where the pump, filter, heater, chlorinator, and automation system live. Plan the pad location for:

• Easy access for maintenance
• Proximity to the pool (shorter pipe runs mean less friction loss)
• Adequate drainage (heater discharge, backwash water, winterization drainage)
• Code-required setbacks from doors, windows, and property lines

Pressure Testing

After all plumbing is installed and before shotcrete, pressure test every line. Standard practice is 20 to 25 psi for 24 hours with no drop. Mark every pipe and fitting with paint or flagging so the shotcrete crew can see them during application.

Shotcrete Application

Shotcrete day is the big event. The pool shell goes from a cage of rebar and pipes to a solid concrete structure in a single day.

Pre-Shoot Preparation

• Dampen the excavation walls to improve bonding (but no standing water)
• Verify all plumbing is pressure tested and flagged
• Confirm rebar inspection has passed
• Protect any adjacent structures, landscaping, and hardscape from overspray
• Have a cleanup crew ready because shotcrete overspray goes everywhere

Application

Shotcrete is applied at 400 to 600 psi nozzle pressure by a trained nozzleman. Key practices:

• Shoot from bottom up on walls to support the fresh material
• Build to proper thickness (typically 6 to 8 inches for walls, 6 inches for floors)
• Minimize rebound by holding the nozzle at the proper distance (3 to 5 feet) and angle (perpendicular to the surface)
• No cold joints: The entire shell should be shot in one continuous session. Stopping and restarting creates weak planes.
• Embed all plumbing fittings including return fittings, light niches, and skimmer bodies to their proper depth

Quality Control

After application:

• Probe the shell thickness at multiple points using a probe rod or small drill
• Check that plumbing fittings are at the correct position and depth
• Verify the shell profile matches the plan dimensions
• Begin curing. Wet cure for a minimum of 7 days, either by flooding the pool or using sprinklers and wet burlap.

Shotcrete core samples may be required by the engineer or building department. Typical compressive strength requirement is 4,000 psi at 28 days.

Tile and Coping

Once the shell has cured, the finish work begins. This is where the pool starts looking like a pool.

Waterline Tile

The waterline tile band sits at the water surface level and provides a durable, cleanable surface at the most visible and chemical-exposed area of the pool. Typical details:

• Height: 6 inches (one row of 6x6 tile) or 12 inches (two rows) is standard
• Setting material: Thinset morite rated for submerged application
• Grout: Epoxy grout or polymer-modified grout rated for pool use. Standard sanded grout will fail in the chemical environment.
• Elevation: The top of the tile should be 1/4 to 3/8 inch below the bottom of the coping to create a reveal line

Coping

The coping caps the pool beam and provides the finished edge between the pool and the deck. Options include:

• Precast concrete coping: Factory-made units in various profiles (bullnose, flat, cantilevered). Durable and cost-effective.
• Natural stone: Travertine, limestone, flagstone, and bluestone are popular choices. Set on a mortar bed over the bond beam.
• Poured-in-place concrete: The deck is poured right up to and over the pool edge with a formed bullnose. Clean look but requires careful forming.
• Brick: Traditional look, set on mortar with proper drainage behind the coping.

All coping must slope away from the pool at a minimum of 1/4 inch per foot to prevent deck water from running into the pool.

Electrical

Pool electrical work is governed by NEC Article 680, which has specific requirements that go beyond standard residential electrical.

Bonding

Bonding is the most misunderstood and most frequently failed inspection item in pool construction. NEC 680.26 requires bonding of:

• All metal parts within 5 feet of the pool (ladders, rails, light niches, drain covers)
• The pool shell reinforcing steel (a #8 solid copper conductor connected to the rebar at four points around the perimeter)
• Metal parts of the pool equipment (pump, heater, filter housing)
• Any metal within 5 feet horizontally of the pool water’s edge (fence posts, window frames, conduit)
• The pool water itself (through a listed pool water bonding device or metal return fitting)

The bonding grid connects all of these components together, not to ground, but to each other. This equalizes voltage potential and prevents electrical shock.

GFCI Protection

Every circuit serving pool equipment, lighting, or receptacles within 20 feet of the pool must have GFCI protection. This includes:

• Pool pump motor (GFCI breaker or GFCI disconnect)
• Underwater lights
• All receptacles within 20 feet of the pool edge
• Receptacles serving the equipment pad

Underwater Lighting

Pool lights are installed in niches (stainless steel or plastic housings) set into the pool wall during the steel and plumbing phase. Key details:

• LED is now the standard. Color-changing LED fixtures consume 15 to 50 watts compared to 300 to 500 watts for the old incandescent fixtures.
• Conduit: 1-inch rigid or flexible conduit from the niche to the junction box (J-box) behind the pool wall. The J-box must be at least 4 inches above the waterline and at least 4 feet from the pool edge.
• Extra cable: Leave 12 to 18 inches of extra cable coiled in the niche so the light can be pulled up to deck level for bulb replacement without draining the pool.
• Circuit: Dedicated 20-amp circuit with GFCI protection.

Equipment Electrical

The equipment pad needs:

• Dedicated circuits for pump(s), heater, and automation system
• A disconnect within sight of the equipment
• A convenience receptacle (GFCI) for maintenance equipment
• Conduit to the automation panel for control wiring

If the pool has a gas heater, coordinate the gas line installation with the plumber. The heater needs a gas shutoff valve, proper BTU-rated gas line, and clearances per the manufacturer and local code.

Interior Finish

The interior finish is the final coating applied to the pool shell. It is what you see when you look into the water, and it needs to be both beautiful and durable.

Plaster

Traditional white marcite plaster (Portland cement, marble aggregate, and water) is the most economical option. It provides a smooth, white finish that makes the water look blue. Lifespan is 7 to 12 years before resurfacing is needed.

Quartz/Pebble Finishes

Premium aggregate finishes mix colored quartz, river pebbles, or glass beads into the plaster mix. These finishes are more durable (12 to 20+ years), more stain-resistant, and available in a wide range of colors and textures.

Popular brands include PebbleTec, PebbleSheen, and NPP (National Plasterers & Pool). Each has specific application requirements that the plasterer must follow.

Application

Plaster application is a one-day, time-critical process:

1. Prep the shell surface (acid wash or bond coat application)
2. Apply the base coat (scratch coat) and let it set briefly
3. Apply the finish coat and trowel to a smooth surface
4. Begin filling the pool immediately. Do not let the fresh plaster dry out.
5. Follow the manufacturer’s startup procedure for chemical treatment and brushing

Pool Deck Construction

The deck is the largest visible element of the pool project and takes the most abuse from weather, chemicals, and foot traffic.

Concrete Decks

Most pool decks are poured concrete with a decorative finish:

• Broom finish: Basic, slip-resistant, cost-effective
• Stamped concrete: Imitates stone, brick, or tile patterns. Requires experienced finishers.
• Exposed aggregate: Seeded or revealed aggregate for a textured, slip-resistant surface
• Cool deck / spray texture: Acrylic-based coatings that reduce surface temperature. Very common in hot climates.

Concrete decks should be 4 inches thick minimum on 4 inches of compacted base. Control joints every 8 to 10 feet and expansion joints at the pool coping and any adjacent structures.

Paver Decks

Concrete or natural stone pavers set on a compacted sand bed offer easy repair and replacement. Pavers also flex slightly with ground movement, reducing cracking. Edge restraints and proper base preparation (6 to 8 inches of compacted aggregate) are essential.

Drainage

Deck drainage must move water away from the pool and away from the house:

• Slope: Minimum 1/4 inch per foot away from the pool edge (except the coping, which slopes away from the pool)
• Perimeter drains: Channel drains or slot drains around the deck perimeter capture runoff
• Area drains: Point drains in low spots where water collects
• No deck drainage into the pool: This washes dirt, chemicals, and debris into the pool water

Managing the Pool Construction Process

A pool project involves excavation, steel, plumbing, electrical, shotcrete, tile, coping, plaster, decking, fencing, landscaping, and equipment installation. That is 10 to 12 trades on a single project, often in a residential backyard with limited space and an anxious homeowner watching from the kitchen window.

Keeping all of those trades coordinated and on schedule requires a real project management system, not a whiteboard and a phone. Projul is built for this kind of multi-trade residential construction. You can schedule each phase, track material deliveries, share updates with the homeowner through a client portal, and keep your entire crew aligned on what is happening next.

If you are building pools and managing the chaos with spreadsheets and text messages, schedule a demo of Projul and see how it simplifies the process. Or check the pricing page to find a plan that fits your operation.

Safety and Compliance

Pool Barriers

Every jurisdiction requires a barrier (fence) around the pool area. Common requirements per the IBC and IRC:

• Minimum height of 48 inches (some jurisdictions require 60 inches)
• No openings that allow a 4-inch sphere to pass through
• Self-closing, self-latching gates that open away from the pool
• Latch height at least 54 inches from grade on the outside of the gate

Anti-Entrapment

The Virginia Graeme Baker Pool and Spa Safety Act (VGB Act) requires:

• Drain covers compliant with ASME/ANSI A112.19.8
• Dual main drains for pools and spas
• Safety vacuum release systems (SVRS) or equivalent for single-drain configurations (where allowed)

Chemical Safety

If the pool has an automated chemical feed system (salt chlorine generator, liquid chlorine feeder, acid feeder), make sure the equipment is installed per manufacturer specs with proper ventilation and containment.

Wrapping Up

Pool and spa construction is a rewarding niche that combines structural concrete work, plumbing, electrical, and finish craftsmanship into a single project. The key to doing it well is getting the sequencing right, coordinating your trades, and paying attention to the details that affect long-term durability.

Take the time to plan each phase, communicate with the homeowner about realistic timelines, and use a project management tool that keeps everyone on the same page. The projects that go smoothly are the ones where nothing is left to chance.