How To Build a Deck In 2026: A Complete Guide
Building a backyard deck is one of the most effective ways to expand your outdoor living space and increase your home’s curb appeal. But before you start cutting lumber, you need to know what the project involves. A deck must safely support weight, withstand the weather, pass inspections and last for years. This guide walks you through everything: planning, framing, materials, and realistic cost expectations.
Deck Planning & Design: Start With a Solid Deck Plan
Every successful project starts with a clear deck plan. Before building a backyard deck, define the basics:
- How will the space be used?
- Ground-level or elevated?
- Attached to the home or freestanding?
Measure your yard carefully and sketch the layout to scale. When planning, account for:
- Property setback rules
- Utility lines
- Door clearance
- Proper drainage away from the home
If the deck will attach to your house, ensure the ledger board is secured directly to structural framing. This is one of the most critical structural components.
Finally, verify local permit requirements. In many Illinois municipalities, attached decks or decks over 30 inches high require permits and inspections.
Proper planning prevents costly mistakes later.
Best Tools for Building a Backyard Deck
To build safely and accurately, you’ll need:
- Circular or miter saw
- Drill or impact driver
- Measuring tape
- Speed square
- Chalk line
- Level
- Post hole digger or auger
- Safety glasses and gloves
Use blades rated for composite or pressure treated lumber to ensure clean cuts.
How to Build a Deck Step by Step
Step 1: Plan and Mark the Layout
Start with a clear deck plan. Measure your space, account for setbacks, and mark the perimeter using stakes and string lines. Double-check that the layout is square by measuring diagonally corner to corner.
Step 2: Dig Footings and Pour Concrete
Footings anchor your deck to stable ground and prevent shifting or settling over time. Two common approaches:
Traditional concrete footings need holes dug below the frost line.
In Illinois, that is usually 42 inches deep.
After that, you pour the concrete and wait until it fully cures.
Afterwards, you can continue building on it.
Helical piers are a faster alternative. Specialized equipment drives them into stable soil. They provide immediate structural support without waiting for concrete to cure. They’re a popular choice for both new builds and deck replacements.
Step 3: Install the Ledger Board (If Attached)
If the deck connects to your home, secure the ledger board directly to structural framing using approved fasteners. Install flashing above it to prevent water damage.
Step 4: Build the Frame
Install posts, beams, and joists according to your deck plan. Most wood decks use 16-inch joist spacing, while composite may require 12 inches for added support. To protect the framing long-term, apply joist tape along the top edge of each joist before laying decking boards. This prevents water from sitting on the wood and extends the life of the structure significantly.
Step 5: Install Deck Boards
Lay decking boards perpendicular to joists. Leave proper spacing for expansion and secure them using corrosion-resistant screws or hidden fasteners.
Step 6: Add Stairs and Railings
Measure carefully when building deck stairs to ensure consistent rise and run. Install railings if required by local code.
Step 7: Finish and Protect
If using pressure treated lumber, apply stain or sealer once the wood has dried. Composite decking does not require sealing.
Deck Building Materials: Choosing the Right Option
Choosing the right materials ensures your deck lasts and looks great. Here’s an overview of common options:
Pressure Treated Wood
Lower upfront cost ($15 – $25 per sq. ft.).
Needs regular staining and sealing to protect against rot and warping.
Prone to splinters and insect damage.
Composite Decking
Made from recycled plastics and wood fibers.
Low maintenance – no staining or sealing needed.
Durable and resistant to rot, warping, and insects.
Available in premium lines like Trex Signature®. Transcend®, Enhance®, or Select®.
Higher initial cost but saves money long-term on upkeep.
PVC Decking
100% synthetic, very low maintenance.
Resistant to mold, mildew, and stains.
Typically higher cost, ideal for extreme weather.
Fasteners and Finishes
Use corrosion-resistant fasteners like stainless steel or Trex’s Hideaway® hidden fasteners.
Choose stains or sealers suited for your material if using wood.
Deck Building Materials: Choosing the Right Option
Material selection affects cost, maintenance, and long-term durability.
Pressure Treated Wood
Pressure treated lumber is one of the most common materials used when building a backyard deck. It has a lower upfront cost and is widely available.
However, pressure treated decking requires regular sealing or staining to prevent cracking, splintering, and moisture damage. Maintenance costs increase progressively over time.
Composite Decking
Composite decking is made from recycled wood fibers and plastic. Composite decking is durable, resisting rot, insect damage, and warping, and requires no staining or sealing.
Many homeowners prefer it for long-term performance and lower maintenance demands. Although the initial costs are higher, this investment often reduces long-term expenses.
PVC Decking
PVC decking is fully synthetic and highly resistant to moisture. It works well in wet environments and offers minimal maintenance. Manufacturers typically price it higher than both wood and composite options.
Common Mistakes When Building a Backyard Deck
Many DIY builders focus heavily on surface boards and overlook structural details.
Common mistakes include:
- Installing footings too shallow
- Improper ledger flashing
- Incorrect joist spacing
- Using the wrong fasteners
- Ignoring slope for drainage
If you are unsure about framing or load needs, ask your local building department or a professional first.
DIY Deck or Hire a Professional?
A ground-level, freestanding deck is a realistic DIY project if you have solid carpentry skills. It also helps to be patient with permits. But the scope changes quickly once you elevate a deck or attach it to your home.
Attached decks involve ledger board connections that directly affect your home’s structural integrity. Elevated decks require precise load calculations and framing. Both typically require permits, inspections, and work that has real safety consequences if done incorrectly.
If you are unsure at any point, like footing depth, joist sizing, or code compliance, consult a licensed contractor.
It costs much less than correcting errors once you’ve already built.
Final Thoughts
Learning how to build a deck requires more than just laying boards. From developing a proper deck plan to installing footings below frost depth, every stage impacts performance and safety.
Regardless of whether you build the deck yourself or hire a professional, proper planning and material choice are critical.
Consult a licensed professional if you have any doubts, ensuring your deck is safe, compliant, and durable.
A properly built deck adds usable living space, increases home value, and enhances your backyard for years to come.
FAQs About Deck Building
How much does it cost to build a deck?
Deck costs vary depending on materials, size, and complexity. Composite decks typically run $80 to $120 per square foot installed, including labor, permits, and extras like railings and stairs. A 12×16 composite deck usually comes in around $20,000.
How to build steps for a deck?
First, measure the rise (height) and run (depth) of each step. Then cut the stringers to fit these measurements. To make things easier, you can buy pre-cut stringers at most lumber stores. Don’t forget to add railings if your deck is over 30 inches high to keep it safe and meet building codes.
Does composite decking need maintenance?
Composite decking requires little maintenance compared to wood. You just need to clean it occasionally – usually with soap, water, and a soft brush or a gentle pressure wash. Unlike wood decks, composite doesn’t need staining, sealing, or painting, so it saves you time and money.
Also resistant to rot, warping, and insect damage, which means it stays looking good for years with minimal effort. Just be sure to remove leaves and debris regularly to prevent stains or mold buildup.
Can I reuse the frame from my existing deck?
You can only reuse it if the frame is strong and meets local building codes. Most deck remodels end up replacing the frame to be safe and up to standard.
Do permits apply to low decks?
In most Illinois towns, you must get a permit if you build a deck attached to your house or higher than 30 inches off the ground. Even for low-profile decks, local building codes may still apply especially if you’re adding features like stairs or railings. Always check with your city or village building department before starting your project to avoid delays or fines.
