The frame is the most important part of the deck. It bears all the weight of whatever is placed on top and must be built with care to hold up to predicted loads. The sizing and spacing of joists depends on the dimensions of the deck and the predicted tolerance necessary. For example, if a hot tub will be put on the deck, the joists will need to be more substantial.
Things You'll Need
- Tape measure
Measure the available space using the tape measure. Decide on the the height of the deck, the length and width of the deck. Consider what type of wood you'd like to use; different woods have different hardnesses and strengths.
Decide on the tolerance needs you have for your deck. Will you often be throwing large parties that will take place on the deck? Will you have a hot tub or a grill on the deck? Larger joists will be needed if the deck is to withstand these higher pressures.
Determine joist sizes based on the decisions made in steps one and two. The dimensions of the joist typically are: 2 by 6, 2 by 8, 2 by 10 or 2 by 12. 2 by 10 is the most common, general-purpose size. For a smaller simpler deck, like a ground-level 8-foot-by-10-foot deck, 2-by-6 joists every 16 inches is an acceptable design. For a tall, long and wide deck that will be supporting a lot of weight and traffic, 2-by-10 or even 2-by-12 joists mounted at 12 inches on center is a preferable option.
Tips & Warnings
- If you're unsure about the dimensions of your deck, contact a professional carpenter who is familiar with building codes.
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