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The short answer: deck joists are typically spaced either 12 inches or 16 inches apart, on center. (On-center means the length from the center of one joist to the center of the next joist, rather than a gap from edge to edge).

## How far apart do decking joists need to be?

For residential decking, the joist space should not exceed 16 inches as measured on the centre. But if you want a more rigid feel for your decking, you can space the joist by 12 inches on the centre. Additionally, for commercial deckings, the standard joist spacing is 12 inches on the centre.

## How far apart should decking joists be UK?

Decking joists should be spaced at 400mm centres. Structural posts should be positioned no more than 1800mm apart. Use a joist and spirit level to mark the ledger height at the wall. Joists are attached to the ledger or double beam with galvanised joist hangers.

## Can I use 4×2 for decking joists?

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.

## How many joists do I need for a 12×12 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 far apart should Supports be for a deck?

Starting with your perimeter, mark the location of each deck post to locate the fitting position. In general, posts should be spaced no more than 8 feet apart. Some builders position them every 4 feet for a completely rigid frame. The maximum distance between footings is determined by the size of your joist material.

## How do I calculate deck 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.

## Is 4×2 strong enough for decking?

2×4 Deck Joist Can Only Span 5’8″ (1.72m) Between Supports. Either you are limited to a small deck, less than 6′ (1.8m), or you will need a mid-span beam. Three 6×6 posts, one on each end plus at mid-span, allow you to use 2×4 joists but is still strong enough to not flex with every step.

## Can I use 2×4 for decking?

For the deck surface, you can use 2x4s, 2x6s, or 5/4x6s. The 5/4 decking (pronounced “five-quarter”), available in cedar and pressure-treated fir, is 1 inch thick and 5-1/2 inches wide with rounded edges that make for a splinter-free surface.

## How far can you span a 2×4 deck joist?

A 2×4 can span a maximum of 6′ 7” when spaced 16” apart and used as a floor or deck joist. When used as a ceiling joist or a roof rafter, a 2×4 can span up to 7′ 3” spaced at 16”, and 6′ 4” when spaced 24” apart.

## How do you calculate 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.

## Are 2×6 strong enough for deck joists?

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″.

## How many joists do I need for a 20 foot deck?

A 20-foot wide deck, for example, would require two beams: one at 10 feet and one and 20 feet in order to support a deck with 2×8 joists spaced 16 inches apart.

## What is the minimum gap between decking boards?

Proper Gap between Decking Boards When installing decking boards, make sure to leave 1/4 to 1/8 inch gaps in between them. This gap will make sure that the decking can breathe, have sufficient drainage, and make it easier to clean.

## How many deck joists do I need?

For example, when you space joists 16″ apart — which is standard for residential decks — a deck spanning 9 1/2′ would require 2-by-6 joists, a 13′ deck would need 2-by-8 joists and a 16′ deck calls for 2-by-10 joists.

## How many boards do I need for a 12×12 deck?

You will need 18 boards of 2-by-6-inch lumber or nine 2-by-10 inch boards to build the joists, also known as the beams. You should purchase an additional 25 percent wood to allow for framing pieces and waste.

## What size bearers and joists for a deck?

The bearers have to carry the weight of the entire deck and whatever is put on top of it, so they need to be strong. A 140×45 treated pine bearer will usually do the trick. Every 1.2 metres, a 90×90 H4 treated pine post will be needed.

## What size timber do you use for decking frame?

The frame The key to constructing a good decking area is the frame. If the decking is being built on a low level it should be built of C16 graded treated joists 45 mm by 95mm (4×2 approx.). However if you are building a raised deck you should use 45mm x 145mm joists.

## Can you use joist hangers for decking?

If you install them properly, joist hangers will keep your decks and floors strong as wood dries, twists, shrinks and ages. So the next time you hold a square dance or weight-lifting contest on your deck, you’ll rest easier knowing you used joist hangers and installed them the right way.