Build Your Own Deck (1)

Build Your Own Deck, the design phase, is the first stage of our 7-phase example project, to demonstrate the process of designing and building a 10' x 10' (3048 x 3048 mm) deck.

(explore the other 6 phases)

The design phase is the most important part of the project. It is the phase where you determine the location, structure, shape, style, and building code requirements that will be needed in order for you to build your own deck.

Preparing to Build Your Own Deck

While reading through this tutorial, keep in mind that you can apply these deck ideas and building techniques to any size or shape deck project. Of course, you would need to adjust the sizes and spacing of joists, beams, and posts, etc., to meet the requirements of your custom structural design.

Location

If you are planning to build a deck at the back door of an existing home, you might not have much choice on the location, but there could be other objects in your backyard that you could include in your design.

For example, you might have a nearby tree that could provide shade for your deck, at certain times of the day, if you were to build close enough to it. Or, if the tree is too small to provide any shade, consider building around it, maybe it will grow tall in a few years and provide all the shade you need. These are just a few of the many deck design considerations:

What time of day will you spend most of your time on your deck?
Where will the sun be during this time?
Where will the sun be in the middle of the summer?
Where will it be in the middle of the winter?
Is there a particular view that you would like to see as you drink your morning tea or coffee, or your evening cocktail?

If you live in the northern hemisphere, build your own deck on the south side of your home, if possible. The north wind will be blocked in the winter, allowing for more warm days on your deck.

You can build your own deck any shape or size you want. That is one of the great things about building a deck. If there is an object in your yard that is in the way, you can build around it (or even over it). You can build a multi-level deck with connecting stairs. You can make it hexagonal, octagonal, or even circular shaped. You can build it around an above-ground pool. You can build it to accommodate a hot tub. You can build a gazebo onto it. You can even build a patio cover over it. The list of options goes on and on.

Style

The 10' x 10' (3048 x 3048 mm) deck example presented here will be shaped square (obviously), with 6x6 posts. The posts will be used for vertical support of the outer beam and deck. The other end of the deck, the inside part, will attach to the house's concrete foundation.

There are several methods for attaching a deck to a house, depending on the design of the house's foundation. For this example, we'll assume the house has a concrete foundation, and the deck will be attached to it using concrete anchors.

For the deck frame, structural grade 2x8 pressure treated lumber is required. The deck surface will be 2x6 (51 x 152 mm) lumber.

The deck surface material can be the same pressure treated lumber used for framing. Pressure treated lumber is typically less expensive than other species and is a perfectly acceptable lumber choice. In rainy or damp regions, pressure treated material is perhaps the best choice for decking.

You can also use Western Cedars or Redwood for decking material. They both have natural resistance to decay, and are very easy to work with. There are several types of wood sealers available for preserving cedar and redwood. I recommend lots of research before selecting a particular type of sealant. Even after you have made your decision, test it out on a piece of scrap material to see if it lives up to your expectations, before you apply it to your new deck.

When designing a deck or any structure, consider the dimensions of the purchased material. In the USA, most lumber is sold in lengths of two foot increments. It makes sense to design your projects to ensure the amount of waste is minimized.

Our 10' x 10' deck is a perfect example for relaying this point. For instance, if you were to build this same deck only 9 feet wide, you would still have to buy the same 10-foot lengths of decking material to cover it, but after you cut off the excess material, 10 square feet of valuable deck space would end up in the landfill!

Structure

In most cases, a Building Permit will be required before you can build your own deck. The permitting authorities will require a drawing that shows all structural specifications. Several of them are listed below:

A detail of how the ledger board will be attached to the existing structure.
The sizes, lengths and spacing of joists.
The size and length of any required beams.
Post sizes, spacing and lengths.
Fasteners (screws, nails, lag bolts, joist hangers, etc.)
Footing sizes and depths.
Stair specifications (see Building Deck Stairs (Phase 5))
Deck and Stair Railing specifications (see Phases 6 and 7)

While designing your deck, you must consider wood structure. To determine the size, length and spacing of joists, refer to the Maximum Joist Spans and Overhangs section of the Prescriptive Residential Wood Deck Construction Guide, by the American Wood Council (AWC) (link at bottom of this page).

From the table of maximum joist spans, you will notice that a Southern Pine 2x8 (51 x 203 mm) spaced 16 inches (406 mm) apart can span about the same distance (11'-10") as a Southern Pine 2x10 (51 x 254 mm) spaced 24 inches (610 mm) apart (11'-5"). This might come in handy, for example, if your ground clearance might not have the space for a 2x10, but by merely using 2x8 joists and spacing them closer together, the same structural requirements can be met.

The thickness of the deck surface material is also another consideration for joist spacing. Since the 10' x 10' deck is designed with 2x6 inch (where the actual size is - 1 1/2" x 5 1/2") decking, the joists could be spaced 24" apart (provided they still meet the design load requirements).

Thinner decking, like 5/4 inch (pronounced "five-quarter"), requires that the joists be spaced no more than 16" apart. Since the 5/4" decking is only 1 1/4" thick, the joists need to be placed closer together in order to support the thinner material.

For deck design and structural information, check out the Prescriptive Residential Wood Deck Construction Guide, by the American Wood Council.

What next?

Continue to Step 2 (of 7): (Deck Framing)

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