In the past, many **decks** were built with **4×4** support **posts** (also called structural **posts**). But these **can** bow seriously, even if a **deck** is only 3 feet off the ground. For that reason, **we** strongly recommend that **you use** 6x6s instead, even if your building department **does** not demand them.

Similarly, Should deck posts be set in concrete?

A **deck post should** always be placed on top of footing, not inside **concrete** because it can break. When **concrete** is poured around a **deck post** in this way, the **post** will rot due to moisture buildup by the soil.

Also, How far can you span deck boards? **Decking boards span** from joist to joist. **If you** use 5/4 **decking**, joists must be no farther apart than 16 inches. **Decking** made of 2x4s or 2x6s **can span** up to 24 inches.

**28 Related Questions and Answers Found π¬**

Table of Contents

**What size lumber can span 20 feet?**

Maximum Span (ft – in) | ||
---|---|---|

Nominal Size (inches) | Joist Spacing Center to Center (inches) | Lumber Grade |

2 x 12 | 24 | 13′ – 2″ |

2 x 14 | 12 | 20′ – 10″ |

16 | 18′ – 0″ |

**Should I use 2×6 or 2×8 for deck?**

In general terms, joists spaced 16 inches on center **can** span 1.5 times in feet their depth in inches. A **2×8** up to 12 feet; 2×10 to 15 feet and 2×12 to 18 feet. The larger the **deck**, the larger the joists. **2×6** joists **should** only be used on ground-level **decks** that do not require, and will not provide for, any guards.

**How big of a beam do I need to span 20 feet?**

**20**foot clearspan

**beam**size

In that case, you **need** something like a 12-16″ GLULAM or LVL to **span** the **20**‘ and can use simple 2×8-10 dimensional lumber 16″OC as floor joists.

**How far can a triple 2×6 beam span?**

A **triple 2×6 beam** over a **span** of 10′ feet should be more than sufficient for normal deck loads. Maximum **span** for a single **2×6** #2btr yellow pine is around 9′ feet.

**How many post holes should be in a deck?**

**How Many** Footing Do You Need For Your **Deck**? The answer depends on the size and shape of your **deck**, the size of your **footings**, and the size of your beams. The larger the beam and footing size, the fewer **footings** that are required. For most situations, you will want to place **footings** and **posts** less than 8′ apart.

**How strong is a 6×6 post?**

As this screencap from it will tell you, a **6×6 post** can support 20,000 even when 12′ highβif cross-braced and secured properly.

**What size footings do I need for a deck?**

Assuming a minimum soil bearing capacity of 1,500 psf, 8-inch-diameter concrete piers bearing on square **footings** measuring 2 feet on a side and 9 to 11 inches thick are adequate for most single-story **decks** where beams are spaced 14 feet apart or less and joist spans are 14 feet or less (see table below).

**Can I use deck pier blocks instead of footings?**

For most situations, you will want to **place footings** and posts less than 8′ apart. If you are planning on **installing** a hot tub or porch on top of your **deck**, you will usually need more **footings** and posts to support the additional loads.

**Do you need footings for a deck?**

The IRC requires frost **footings** to be installed for all **decks** that are attached to a house in most climate zones. These **footings** will have to be inspected to make sure they are capable of supporting your **deck** and will resist damage from frost.

**How much can a 4×4 post support?**

What I figured if the weight is distributed evenly is that each **4×4 post** is **supporting** a max of about 420 pounds.

**How deep do you dig post holes for a deck?**

**Dig** footing **holes** about 6 inches **deeper** than required. Fill the bottom of the **hole** with 6 inches of gravel and compact the gravel with a 2×4 or wood **post**.

**How do I calculate decking squared?**

To find this multiply the width of the floor-board in feet times the length in feet. You can use our feet and inches **calculator** to convert the board width in inches to feet. To find the number of boards you need, divide the total **deck square** footage by the board **square** footage, eg. total ft^{2} / board ft^{2}.

**How much does it cost to build a 12×12 deck?**

**How far can a beam span without support?**

When supporting joists that span 12 **feet** with no overhang beyond the beam, a double ply beam can span in **feet** a value equal to its depth in inches. A double 2×12 beam can span 12 **feet**; a (2) 2×10 can span 10 **feet** and so on.

**How far can I span a double 2×8?**

No, you cannot **span** 23 feet with conventional lumber, even doubled. It’ll be as bouncy as a trampoline and won’t meet code, and that’s if you **can** find such lengths. You’ll need at least a 12″ (nominal) I-joist or an engineered floor truss to **span** that **far**, or you’ll need an LVL or steel beam midway.

**How much does it cost to build a deck with stairs?**

Adding simple footings beneath the concrete pillars averages $1-$2 per square foot. Adding railings or **stairs** to a **deck** will also increase its **cost**. The **average cost to install** steps and railing ^{6} is $30-$35 per square foot. A long flight of steps will **cost** more to **install** and averages $48-$55 per square foot.

**Can you use 4×4 posts for a deck?**

In the past, many **decks** were built with **4×4** support **posts** (also called structural **posts**). But these **can** bow seriously, even if a **deck** is only 3 feet off the ground. For that reason, **we** strongly recommend that **you use** 6x6s instead, even if your building department **does** not demand them.

**How much does it cost to build a 10×16 deck?**

Doing it yourself, you can **build** an 8×10-foot ground-level **deck** from treated lumber for about $500 in materials. Having a contractor **build** it for you raises the **price** to $1,500. You **could build** a treated-lumber raised **deck**, say **10×16** feet, for about $1,500 in materials.

**How much weight will a 4×4 beam support?**

In general, a 2Γ4 wooden **beam can support** the **weight** up to a ton horizontally, and thus, a wooden **beam** of 4Γ4 **can** easily **support** double of the **weight** mentioned above horizontally.

**Can I use deck pier blocks instead of footings?**

**10×10 deck**

You **should** really use 2×8’s or 2×10’s. For a **10×10 deck** (small) – you really only **need** 4 **posts**, but you can **do** more if you’re a glutton for punishment. If you cantilver the **deck** 2 feet on all four sides then you only have 6 foot spans between your **posts**.

**Are 6×6 fence posts better than 4×4?**

**How to Calculate Footing Size**

- Determine the width and length of the cement slab in inches.
- Divide the width by 12 to convert it to feet.
- Divide the length by 12 to convert it to feet.
- Determine the depth or thickness that is required for the footing in inches.
- Multiply the width by the length and then by the depth.

**How do I make deck stringers?**

**Step-by-step**

- Clamp a guide to the square.
- Find the crown.
- Lay out the first tread and the second riser.
- Lay out the second tread and the third riser.
- Mark the back of the top tread.
- Mark the plumb cut at the top of the stringer.
- Lay out the bottom riser.
- Adjust the first riser height.

**How many footings do I need for a shed?**

An 8 ft x 12 ft **shed will need** 6 piers, 3 per long side. Typically, the span between two piers is based on the dimensions of the beams and the joists. A double 2Γ8 beam **should** be supported every 4 to 6 feet. A 2Γ8 joist **can** normally span 8 feet.

**How many footings do I need for a shed?**

A **deck pier block** is in many ways just a simplified version of a βprecast foundationβ, a foundation type recognized by building codes. They’re subject to all of the same requirements as a typical **footing**, regardless of not being cast-in-place. The small bearing area of **pier blocks** is limited in supporting much load.

**How do you build a deck without digging holes?**

**Precast piers make it unnecessary to dig holes for your deck.**

- Set your precast deck piers in a grid, at roughly three- to four-foot intervals.
- Measure your grid diagonally from corner to corner, using a measuring tape.
- Extend the line level to determine if the piers are level as a helper holds the other end.

**How much weight can a 2×6 deck support?**

In short there’s no one right answer to βhow much can my deck hold?β However, one rule of thumb to keep in mind while answering the question is that the answer commonly is that if a deck is properly designed, it’s built to hold **50 lbs**. per square foot. It’s possible that it could hold much more weight than **50 lbs**.

**Do deck posts need to be anchored?**

In order for **posts** to properly resist varying degrees of weight, **posts** must rest on and be **anchored** to concrete footings. It’s important to note that patios and pre-cast concrete piers **do** not qualify as proper footings for **deck** construction. To **anchor posts** to concrete footings, you **need** to use a **post** base connector.

**How many footings do I need for a 12×12 deck?**

For an attached **12 x 12**‘ **deck**, you’ll need at least 3 **footings**, plus at least 2 more if you’re planning on building stairs with it. If your **deck** will be a different size, it’s easy to figure out **how many** you’ll need.

**How do you calculate footing size?**

In short there’s no one right answer to βhow much can my deck hold?β However, one rule of thumb to keep in mind while answering the question is that the answer commonly is that if a deck is properly designed, it’s built to hold **50 lbs**. per square foot. It’s possible that it could hold much more weight than **50 lbs**.

**What size bolts to use for deck posts?**

At connections carrying structural loads, such as **deck** ledgers or railing **posts**, **use** through-**bolts** or lag **screws**. Through-**bolts** are stronger and should **be used** where possible. For the heaviest connections on a **deck**, such as where ledgers attach to the house or to **posts**, **use** 1/2-inch **bolts** or lags.

**Which is stronger 2×6 or 4×4?**

**How to Calculate Footing Size**

- Determine the width and length of the cement slab in inches.
- Divide the width by 12 to convert it to feet.
- Divide the length by 12 to convert it to feet.
- Determine the depth or thickness that is required for the footing in inches.
- Multiply the width by the length and then by the depth.