* Should deck joists be 2×6 or 2×8?* For upper-level decks, 2×10 is recommended as the minimum size to use for strong guard post connections.

**2×6 joists should only be used on ground-level decks**that do not require, and will not provide for, any guards. … Most decking is not strong enough to support longer spans than 16″.

Also, How many Trex boards do I need for a 12×12 deck?

(Choose from 8, 12, 16, or 20 ft board lengths. Choose which board best fits the dimensions of the deck.

…

Decking Materials.

Board length | Boards required |
---|---|

8 FT | 206 |

12 FT |
137 |

16 FT | 103 |

20 FT | 83 |

How far can a 2×8 span for a deck? Depending on various factors, the maximum span for a 2×8 floor joist is **16′ 6”**. The maximum span for roof rafters is 23′ 9”. For headers, the maximum span is 11′ 2”. Finally, a single deck beam has a maximum span of 5′ 11” and double maxes out at 8′ 9”.

## How do I calculate how many joists I need?

## How far can a 2×8 span without support?

In general, a 2×8 will span 1.5 x 8, so **12-feet**. Based on all factors though, a 2×8 joist span is 7′-1” to 16′-6”, and a rafter 6′-7” and 23′-9”. In this guide, we’ll explain what span means in terms of construction, factors that impact the span, and how much weight a 2×8 can support.

## How many sq ft is 12×12?

How many square feet is a 12×12 room? The square footage of a room 12 feet wide by 12 feet long is **144 square feet**. Find the square footage by multiplying the width (12 ft) by the length (12 ft).

## How do you stagger deck boards?

A common method for staggering a deck is to **start the first row with a full plank, then cut one-third of the next row’s first board off the end**. The row after that has an additional one-third cut off and then repeat when you get back to a full board.

## What is the proper spacing for Trex decking?

Most composite and PVC decking brands, like Trex and Azek, recommend a maximum joist spacing of **16 inches OC**. Some brands, like WearDeck, let you get away with more – reinforced with a layer of fiberglass on both the top and bottom, WearDeck boards easily allow for spans of 24 inches OC.

## Can I use 4×2 for decking frame?

**4 x 2** Timber Rail / Joist

These decking joists are the most common sized framing timber for decking. They provide a solid structure for fixing your decking boards too. When making your decking frame you should use a 400mm spacing between your timber joists.

## Should I use deck boards or 2×6?

**2×6 is thicker and is stronger**, but is also more expensive. Spacing between deck boards provide a few critical functions. The primary function is to drain water from the deck. Gaps that are narrow (1/8”), can catch debris, specifically on top of the joists, and can be difficult to clean out.

## Can I use 2×8 for deck joists?

**2×8 for joists will be fine**, with 16″ OC. Should use 2×10 for beams but 2×8 will be fine as well. If you are worried you can triple the 2×8 for the beams but double will be sufficient. You should put the beams at 7 and 14 feet out from the house, with the piers you should do 3 per beam with spacing of 1, 7, 13.

## How many joists do I need for a 12 foot deck?

For example, a 12-foot x 12-foot deck of 5/4 x 6 pressure treated wood decking on 16 inches on center spacing of joists will require: A 12-foot long deck with joists 16 inches on center will require **10 joists**.

## How do I calculate deck joist spacing?

As a rule, **the larger the deck, the larger the joists**. For example, joists spaced 16 inches from the center of the joist next to it can span 1.5 times in feet the depth of their inches.

## Does double joists increase span?

For example, if you double the thickness or number of joists in a floor, **the distance the boards can span will increase by approximately 25%**. But if you double the width of the boards, the distance the joists can span increases between 80% to 100%, even though you’re using the same board feet of lumber.

## How far can a 2×10 span?

Douglas fir 2-by-10 joists graded as “Structural Select” allows joist spans up to **21 feet** for a live load of 30 pounds per square foot when spaced 12 inches apart, 19 feet 1 inch for 16 inch spacing and 16 feet 8 inches for 24 inch spacing.

## What is the square foot of 10×12?

Area of the floor or ceiling: Multiply the length by the width (10 feet x 12 feet = **120 square feet** of area).

## How many square feet is 10×16?

10×16 Sheds. Square footage: **160 sq.** **ft**.

## How many square feet is a 30×40?

A building of this size (30′ x 40′ = **1,200 square feet**) is a good choice for a 4 car garage or 3 car garage with shop & storage space.

## Is it OK to stagger deck boards?

Staggering the deck boards **decreases** the number of screws or nails going into one joist, which can weaken or rot the joist more quickly. Staggering the joints strengthens the deck by spreading the seams across more joists instead of placing the stress on only one.

## Do I stagger decking?

**Composite decking should not be staggered on a deck**. Staggered decking requires butt joints, but composite decking expands and contracts with temperature changes making butt joints unsightly. It is better to design a composite deck with intentional design elements to avoid staggering boards for a wider composite deck.

## How do you measure deck board spacing?

**Square footage of board spacing = (S) x Length of deck**

Then multiply 0.26 feet by 16 feet to get 4.16 square feet, the total area of board spacing. If the square footage of board spacing is more than one or more boards’ square footage, you may be able to skip purchasing an extra board or two.