Hey there! I‘m Lillie, your home improvement friend here to guide you through building your very own inground hot tub. As an expert with over 15 years of experience renovating bathrooms, upgrading kitchens, and taking on exciting DIY projects, I‘ve helped dozens of homeowners successfully install custom backyard hot tubs.
In this comprehensive guide, I‘ll walk you through everything involved so you can determine if a DIY inground hot tub is the right project for you. Building your own hot tub takes time and skill, but soaking in a hydrotherapy spa right in your own yard makes it so worthwhile!
Let‘s get started planning out your perfect backyard oasis.
Planning Your Dream Hot Tub
The first step is deciding exactly what you want your inground hot tub to look like. Grab a notebook and let‘s start jotting down some ideas! Here are the key factors to consider in your planning:
Size
Typical hot tubs range from as small as 5×5 feet up to large 10×10 feet tubs. Measure out your space and determine an ideal size. Keep in mind, bigger doesn‘t always mean better when it comes to hot tubs. The larger the tub, the more building materials, equipment, and regular maintenance it will require.
- 5×7 feet – seats 4-5 adults comfortably
- 7×7 feet – seats 6-8 adults comfortably
- 8×8 feet – seats 8-10 adults comfortably
- 10×10 feet – seats 10-12 adults comfortably
Shape
Rectangle, square, circle, oval, freeform – the options are endless! The shape you choose impacts the excavation requirements and building materials needed. Rectangle and square tubs are the easiest for DIY installation. Circles involve curved forms. Freeform shapes take more planning.
Depth
A typical depth for hot tubs falls in the 3-4 feet range. Going deeper than 4 feet significantly increases the amount of water volume and building materials needed. More depth also increases the size of equipment like pumps required.
- 3 feet depth – great for sitting
- 4 feet depth – allows standing with shoulders above water
- 5+ feet depth – requires taller side walls
Location
Finding the perfect backyard spot for your hot tub takes some thought. You‘ll need a site that is:
- Level and stable
- Has good drainage
- Allows for access to electrical and plumbing
- Meets local codes for setback requirements – often 5 feet from property lines
Consider views, sunlight, and privacy when choosing your location.
Materials
The shell, or outer structure, is a big decision. The most common inground hot tub shell options include:
- Concrete – reinforced with rebar, durable, less flexibility in shapes
- Fiberglass – prefab shells, lighter than concrete, flexible sizing
- Acrylic – vivid color options, softer material prone to scratching
Consider insulation capability, durability, appearance, and ease of installation. Acrylic and fiberglass shells simplify the process compared to poured concrete.
Features
It‘s time to dream about the features that will make your hot tub unique! Consider elements like:
- Jets – From bubbling back jets to massaging foot jets, the types and placement impact experience
- Lighting – Underwater lighting sets a mood; exterior lighting adds ambiance
- Extras – drinking fountains, waterfalls, fountains, sounds systems
- Seating – Ottomans, benches, loungers customize the space
- Access – Steps, handrails, corner entry
The more features you add, the more complex the installation and higher the cost. Focus on what matters most to your vision.
Budget
As you make decisions on size, features, and components, add up estimated costs. Materials and equipment for a basic 200 square foot hot tub with limited features can cost around $7,000-$10,000. Sprawling multi-featured tubs with premium materials can cost upwards of $30,000.
I always recommend building a scale model with rough dimensions, materials, and features before finalizing plans. This allows you to visualize your dream hot tub design before investing in the full project!
Excavation – Digging In!
You‘ve got your plans – now it‘s time to break ground! The excavation phase creates a solid foundation to support your hot tub.
Here are the key steps:
- Mark out the footprint of your hot tub based on dimensions chosen. Use spray paint or stakes and string.
- Excavate the area to a depth of at least 18-24 inches below final ground level.
- Create a slope of 1-2 inches per foot for proper drainage.
- Remove any large rocks, roots, or debris within the space.
- Store and reuse excess soil later for landscaping needs.
- Call 811 to identify any underground utilities prior to any digging!
Pro tip: Renting an excavator for a few hours makes this process fast and easy. Otherwise, expect a full day or more of manual labor.
Foundation
Once digging is complete, it‘s time to construct the foundation. The base layer provides stable support for the weight of your hot tub.
A 4-6 inch thick reinforced concrete slab is the best option. Here are the steps:
- Lay down gravel fill and compact with a plate compactor.
- Install rebar grid, wiring conduit, and plumbing as needed.
- Build secure forms.
- Fill with 4000 psi concrete, screed, and float.
- Allow to fully cure for 5-7 days before continuing.
This robust foundation will provide a flat, stable base designed to last for decades!
Hot Tub Shell Selection
Now for the fun part – picking the actual shell or vessel to hold all that wonderful, relaxing hot water!
Let‘s take a closer look at the pros and cons of some common hot tub shell options:
Concrete
- Pros: Extremely durable, custom sizes, can be decorated, good insulator
- Cons: Heavy, permanent, difficult to change shape later, cracking risk
- Cost: $3,000-$5,000
Fiberglass
- Pros: Lightweight, available in many sizes, smooth gelcoat interior
- Cons: Can be damaged if mishandled, limited color options
- Cost: $3,500-$6,000
Acrylic
- Pros: Built-in insulation, vivid colors, easily customized
- Cons: Prone to scratching, needs additional bracing
- Cost: $4,000-$7,500
An acrylic or fiberglass shell delivers benefits like light weight, insulation, and eye-catching color. This simplifies installation compared to poured concrete.
I‘d love to hear your thoughts on which shell material sounds most appealing!
Plumbing – Piping in Relaxation
The plumbing circulates and filters the water, so smooth flowing pipes are crucial. Typical components include:
Pipes: Use 2 inch PVC plastic pipes and flexible hoses rated for hot water environments. Runs from the water supply line to the tub, sump pump, filter, and jets.
Pump: This circulates the hot tub water. Match power and size to the volume of your tub. Install with easy access for maintenance.
Skimmer: Collects debris from the water surface into a basket. Position away from jets to prevent interference.
Drains: Install a main drain and overflow drains with a minimum 4 inch diameter. This controls water level and allows for draining.
Filter: The pump pushes water through a filter to trap debris and keep it clean. Size appropriately for tub volume and jet count. Allow easy access to clean regularly.
Jets: Install stainless steel adjustable body jets wherever you want massage bubbles focused. Use a variable valve to control strength.
Having a plumber tackle the technical plumbing work is highly recommended. Future you will appreciate the accessible layout for maintenance duties.
Heating Systems – Warm It Up!
What‘s a hot tub without the heat? The heating system keeps the water temperature comfortable year round.
Electric
- 220v hardwired system
- Simplest for DIYers to install
- Lower operating costs than gas or wood
Gas
- Heat with natural gas or propane
- More complex installation
- Lower operating costs than electric
Wood Stove
- Beautiful and eco-friendly
- Requires manual heating
- Higher operating effort
Select a heating system sized appropriately for the volume of your hot tub. Include an exterior control panel to easily adjust target water temperature.
Electrical – Safety First
Improper electrical work poses serious safety risks. Consulting a licensed electrician is advised. Key requirements include:
- Dedicated 220v GFCI circuit
- Copper wiring sized appropriately for heater wattage
- Outdoor rated junction box above flood level
- Waterproof conduit running to equipment
- Bonding wire connecting metal components
- Local permits and inspections
Take the electrical phase seriously. The last thing you want is avoidable hazards putting your family at risk.
Insulation
Insulation plays an important role in efficiency by preventing heat loss. Here are some common options:
- Foam panels – cut to fit seamlessly around shell exterior
- Polystyrene beads – poured between shell and hole walls
- Spray foam – applied to excavation walls
- Rigid foam sheets – attached to shell exterior
2-3 inches of insulation is usually adequate for heat retention. Avoid underside insulation if installing on a deck.
Properly insulating your inground hot tub can reduce heating costs by up to 30%!
Waterproofing
Preventing water seepage helps avoid damage and foundation issues. Consider these tips:
- Select waterproof shell material like fiberglass or acrylic
- Use waterproof adhesive/sealant on all shell joints
- Concrete shells require waterproof liner
- Install drainage slope away from home
- Inspect for leaks before decking and finishing
Catching any moisture issues early on prevents major headaches down the road!
Safety First!
Safety should always be the number one priority when installing a hot tub. Follow these tips:
- Install childproof fencing with self-closing gate
- Use a locking hard cover when not in use
- Provide slip-resistant steps for safe entry and exit
- Post clear safety signage
- Ensure electrical meets all local codes
- Keep chemicals locked up securely
- Check water chemistry prior to each use
- Limit alcohol consumption in tub
With proper precautions, you can ensure safe and responsible hot tub enjoyment for years to come.
Finishing Touches
It‘s time to add those final touches that make your DIY hot tub uniquely yours!
Decking
Blend your hot tub into the landscape with composite or natural wood decking.
Landscaping
Strategically place trees, plants, rocks, and lighting to complement the space.
Accessories
Customize with conveniences like cup holders, towels hooks, USB charging ports.
Cover
Protect your investment with an insulated, locking vinyl cover.
Shade
Add a pergola, gazebo or umbrella for lounging out of the sun.
Steps
Non-slip steps with sturdy handrail ease entry and exit.
Choose finishes that enhance your yard while complementing your home‘s style.
Expected Cost Breakdown
Here‘s an overview of typical price ranges for major components:
- Excavation – $800 – $2,500
- Foundation – $1,500 – $4,000
- Shell – $3,000 – $7,500
- Plumbing – $2,000 – $4,000
- Heater – $2,000 – $5,000
- Electrical – $3,000 – $6,000
- Insulation – $500 – $1,500
- Waterproofing – $300 – $800
- Accessories – $800 – $2,500
- Cover – $1,200 – $3,000
- Landscaping – $2,000 – $5,000
Total Range: $15,000 – $40,000+ depending on size and features
Performing labor yourself saves substantially on costs. Focus budget on critical steps like plumbing and electrical.
Expected Timeframe
Most DIY inground hot tub projects take 4-10 weeks total. Here‘s a rough timeline:
- Excavation & Foundation: 2-3 weeks
- Shell Installation: 2-5 days
- Plumbing & Electrical: 3-4 weeks
- Heater & Accessories: 2-3 days
- Insulation & Waterproofing: 3-5 days
- Decking & Landscaping: 2-3 weeks
- Filling & Balancing Water: 3-5 days
Hiring pros for complex work like electrical can condense the schedule. Patience and persistence pay off in the end!
Tips for DIY Success
Installing a hot tub yourself is extremely rewarding, but also challenging. Follow these tips to make the project smoother:
- Assemble a team of friends to help – you‘ll need extra hands!
- Rent any equipment you may need – excavator, concrete mixer, etc.
- Have materials delivered to avoid hauling everything yourself
- Start with a simplified rectangular or square design before tackling unique shapes
- Follow all local codes for permits, inspections, etc. to avoid issues
- Watch online video tutorials to visualize each step
- Take photos throughout the process to document progress
- Be prepared for minor problems like leaks or wiring and have a contingency budget
- Research thoroughly before taking on complex steps like plumbing and electrical
- Oh, and don‘t forget to celebrate when you finish!
The passion, effort, and patience required will make enjoying your custom spa even more rewarding.
Hiring Out the Project
For those interested in leaving the hot tub construction fully to professionals, finding an experienced contractor is key:
Benefits of Hiring a Contractor
- Expertise gained from dozens of hot tub installs
- Proper tools, equipment, and team for efficient installation
- Discounts on materials purchased in bulk
- Manages permits and inspections
- Multi-year warranty on work and equipment
- Far faster completion time than DIY
Be sure to get multiple bids and read reviews before selecting your contractor. Cost will typically range from $25,000 – $50,000+ depending on the size and features desired. Maintenance costs also remain.
Either way, soon you‘ll be soaking away sore muscles in your own backyard paradise!
Ongoing Hot Tub Maintenance
To keep your hot tub investment functioning safely for years to come, plan to:
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Test and adjust pH and sanitizer (chlorine/bromine) levels 2-3 times per week. This prevents harmful bacteria growth.
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Run the filtration system for at least 6 hours daily for proper water circulation.
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Drain and refill the tub every 3-4 months to replenish minerals and clean surfaces.
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Remove and clean filters monthly to remove collected debris and buildup.
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Deep clean interior surfaces monthly to control oils, scale, and biofilm.
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Inspect equipment regularly – pumps, heater, jets, for leaks, odd noises, or other issues.
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Keep the insulated cover secured when not in use to retain heat and prevent accidents.
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Watch carefully for any leaks, which could signal plumbing problems.
With proper care and maintenance, your custom inground hot tub can provide decades of warm, relaxing enjoyment! Reach out anytime if you need help keeping your hot tub sparkling.
We‘ve covered everything from initial planning to ongoing upkeep. The prospect of building your own inground hot tub may seem daunting, but the payoff is having your own affordable, custom backyard oasis.
Focus on the features most important to your vision, be diligent in the preparation and installation, and soon you‘ll have an at-home spa experience unmatched even at the nicest resorts.
I hope this guide provided a helpful overview of the entire process. Reach out with any other questions and I‘ll be happy to help! Here‘s to many years of stress-melting soaks in your personal backyard hot tub paradise.
