Before you can start building a deck, you need to spend a sufficient amount of time planning. It’s not fun, but it’s necessary (don’t shoot the messenger).

Planning the layout for your deck involves careful consideration of the available space, your goals, and the functionality you want to achieve. 

The good news is that the deck layout process is relatively simple. The even better news is that this article will show you exactly how to layout a deck from start to finish!

Tools and Materials Recommended for Any Deck Layout Project: 

You really only need a few basic tools to layout a deck. I listed them below and linked my favorite types.

• Stakes
• String Line
• Tape Measure
• Marker

Deck Layout and Planning Considerations

Here are some of the things you will need to keep in mind when planning out your deck: 

1. Measure the space: Take accurate measurements of area in which you plan to build you deck. Note any obstructions such as trees, utilities, or existing yard features (e.g. patios, fire pits, etc.) 
2. Identify the Deck “zones”: I highly recommend that you think about how the deck will be used as part of the planning process. Will you have a dining area? Will you have a dedicated grill area or an outdoor kitchen? Will there be a sitting area with a fire feature? Considering all of these things ahead of time will help you to size your deck accordingly. 

• Electrical Considerations: If you plan on adding railing lights, mood lighting, or just a few electrical receptacles on your deck, it is a good idea to think about all of that during the planning stage. Ensure that electrical outlets are conveniently located for various uses.
• Think about Rain: If you live in a high rain area like Seattle, you may want to consider something like a pergola in your deck design. Additionally, if you deck is located on a second floor or if you plan to use the underside of the deck as a patio or for storage, you may want to consider a deck drainage system. These systems collect any rainwater that would have otherwise “dripped” through the deck and funnel it away to a controlled drainage area. I personally didn’t install one of these systems, but I did think about it. 

Once you have a conceptual idea of how you want to layout your deck, it’s time get that concept “on paper”. 

Sketching or Modeling the Deck

When it comes to sketching / modelling your deck, you basically have two options:  

• 3D Software: Programs like SketchUp, Deck Design, etc. allow you to model your deck virtually. I use the Free Version of Sketchup and it works great for me. There is a bit of a learning curve, but once you get the hang of it, it is a very useful tool.

These tools help you adjust the dimensions, try out different materials, and make sure everything fits before you start building. Some programs also generate materials lists, which can help you estimate how much of each material you’ll need.

• Graph Paper: If you prefer a more traditional method, drawing your deck design on graph paper can work well. Use a scale (e.g., 1 square = 1 foot) to help you accurately represent your design. Include features such as stairs, railings, and seating. A scaled design will help you visualize the layout and make sure everything fits within your available space.

Once you have decided on your final layout, you will want to develop scaled, dimensioned drawings that can be used as the basis for your permitting application (assuming that your deck is being permitted).  

Deck Permitting (Basic Overview)

Because permitting requirements vary significantly from city to city and County to County, I am only going to provide a brief summary of the general deck permitting process. You will need to check with your local permitting department and city for the exact permitting requirements for your area. 

Although Deck  building permits vary from City to City and County to County, the Process is not too bad…

My County has a “Deck Building Resource Guide” which was a pretty helpful resource for planning my deck. Your County may have something similar. 

Basically, if you are building a new deck, you are more than likely required to get a permit. Contact your local planning and zoning department (a quick Google search should point you in the right direction) and give them a call to ask what is required to build a deck in your area. More than likely, it will involve submitting drawings of the proposed deck, a materials list, and you will likely need to pay a permitting fee. You will also likely need to coordinate inspections with your County during the deck building process. 

Many areas have regulations for deck construction that address safety, height, and structural stability. Your deck may need to comply with the International Residential Code (IRC) or local building codes. These codes typically specify how deep the footings must be, the type of materials that can be used, and the design of railings and stairs.

After determining exactly what permits are required for your deck you will need to think about how you will get the work performed. Although many jurisdictions allow for the home owner (you) to serve as the contractor for deck construction, check with your local permitting office.  

Once you have submitted all of your permit applications to your city, you may receive comments that need to be addressed. For example, they may comment that you need additional vertical supports under your deck beam (or something like that). Once your permits are approved, you can begin construction. 

Although the permitting process associated with deck building can be a bit intimidating, it is generally not as bad as it seems. 

With the “boring” aspect of deck building (like permitting…) out of the way, we can begin the deck building process. 

Laying Out The Deck (Very Important)

The “layout” process is the first physical step in the deck building process and is essential for ensuring your deck is square and level. Proper layout techniques prevent problems down the road and make sure everything aligns. As always, if you are more of a visual learner, you can watch my “How to Plan and Layout a Deck from Start to Finish” YouTube video linked below. 

Sometimes, “seeing” is way easier to follow than “reading” – Check out My YouTube video on the Deck Planning Process

But before we can talk about deck layout, it is probably a good idea to spend a quick second looking at the “Anatomy of a deck” so that we are all on the same page when it comes to terminology: 

As illustrated in the image above, a deck consists of the following components:

• Ledger board — attaches to the house
• Joists — run perpendicular to the house
• Rim joist — connects the ends of the joists
• Beam — supports the joists from below
• Posts — support the beams
• Footers — support the posts and transfer load to the ground

You’ll be seeing these terms a lot as you plan out your deck, so it is good to get the terminology out of the way early. 

Below is the process that I used to layout my Deck.  

Step 1: Establishing Perpendicular, square lines from house: 

When I am laying out a deck, I like to start by setting two parallel lines that run perpendicular to the House. These two lines will mark the “width” of my deck. To do this, I like to set one stake at the corner of the house (to mark the edge of the deck) and then I install a batter board around 5’ past the end of the deck. 

• Batter Boards: These temporary wooden boards act as your guide. Hammer stakes into the ground at the corners of your deck layout. Attach horizontal 2×4 or 2×6 boards to these stakes, creating a board that you can attach your string line to. The batter boards provide a sturdy reference point.
• String Lines: Stretch string lines tightly between the stakes to mark the perimeter of your deck. Double-check that the lines are level using a spirit level or laser level. The lines should represent where your posts will be placed, and their accuracy is critical for a square deck.

Step 2: Ensuring the Deck Layout Lines are Square 

Use the 3-4-5 method to check the squareness of your deck’s layout:

1. From the corner where two string lines meet, measure 3 feet along one string, 4 feet along the other.
2. The diagonal between these points should measure 5 feet (forming a perfect right triangle).
3. If the diagonal is slightly off, adjust the string lines until they measure exactly 3 feet by 4 feet and 5 feet diagonally. This ensures a square layout.

Step 3: Setting the String Line for Your Deck Beam(s)

Once the string lines perpendicular to the house (that mark the width of the deck) are established, you can set the string line for your beam. But before marking the beam Location, we need to spend a few a bit of time talking about the following: 

• Joist spans
• Beam spans
• Cantilevers
• Ledger rules
• Post spacing

The maximum distance your beam can be from the house will depend on the type and size of joists you are using. For my deck, I am using 2×8 Pressure Treated Southern Pine joists, spaced 16″ O.C. (“on center”). According to the IRC Section R507 span table below, my Max span = 11 feet 10 inches.

I decided to install my beam at 11’-2” from the house to ensure that I was well within the max allowable joist span. 

To mark the beam line, I measured 11′-2″ out from the house on each side. I then set a stake at each end of the deck 11’-2” from the house and then I connected those marks with another string line.

This line represents the main beam for my Deck.

To make this easy to adjust, I didn’t tie the string to the stake. Instead, I set a small screw into the stake and used a friction knot so I can tighten or loosen the string easily and move it if needed.

This line gives me a perfectly straight reference line for marking footer locations.

Once the Beam location has been established, it’s time to mark the locations for our footings and posts which will support the beam. 

Step 4: Marking the Footing Locations Below the Beam(s)

The spacing for the footings and posts will depend on the type and size of beam you are using. For my deck I used a double 2×10 beam.

According to the beam span charts (based on IRC R507) my max beam span is 7’4″ (i.e. the distance allowed between posts).

For my 30 ft wide deck and a Max Beam span of ~7′-4″ between posts, I calculated that I would need five posts spaced roughly 6½ feet apart

Note: Beam cantilever is allowed up to ¼ of the beam span, so for an 8-foot span, you could have up to a 2-foot beam cantilever, within code limits.

With the footing / post spacing established, you can mark each footer location. To do this, I recommend that you use a tape measure to get the spacing and then use a plumb bob and spray paint to mark each post location directly beneath the beam string.

Repeat this for every footing location on every beam.

Important Note: If you need to splice beams, the splice MUST land directly over a post per the IRC R507 detail shown below: 

Although 99% of decks will only require one beam, my deck will have a Hot Tub at the end of the deck… so that required a few more beams. Although it was likely overkill, I decided to install three beams at the end of my deck where the hot tub is going to be. 

Once all of the footings, posts, etc. have been laid out and marked, you can begin digging and pouring your deck footings. 

Conclusion

Planning your deck layout is absolutely critical for the success of your deck build. Although it can be a bit overwhelming at first, the process is relatively simple once you familiarize yourself with the building codes (IRC R507 in this case). 

However, it is much easier to explain this process through a video than just text alone. If you are more of a visual learner, check out my “How to Plan and Layout a Deck” YouTube video linked below: 

Thanks for reading and good luck with your project!

DISCLAIMER: This is a reference guide only. Consult local code requirements. Links included in this article might be affiliate links. If you purchase a product or service with the links that I provide, I may receive a small commission. There is no additional charge to you! Thank you for supporting ATimprovements so I can continue to provide you with free content each week!