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 💬

 

What size lumber can span 20 feet?

Max. Live Load 60 lbs/ft2 (2873 N/m2)
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?

Re: 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′ high—if 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 ft2 / board ft2.

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 2×4 wooden beam can support the weight up to a ton horizontally, and thus, a wooden beam of 4×4 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
  1. Determine the width and length of the cement slab in inches.
  2. Divide the width by 12 to convert it to feet.
  3. Divide the length by 12 to convert it to feet.
  4. Determine the depth or thickness that is required for the footing in inches.
  5. Multiply the width by the length and then by the depth.

How do I make deck stringers?

Step-by-step
  1. Clamp a guide to the square.
  2. Find the crown.
  3. Lay out the first tread and the second riser.
  4. Lay out the second tread and the third riser.
  5. Mark the back of the top tread.
  6. Mark the plumb cut at the top of the stringer.
  7. Lay out the bottom riser.
  8. Adjust the first riser height.

How many footings do I need for a shed?

Step 2 – Create Foundation Plan

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 2×8 beam should be supported every 4 to 6 feet. A 2×8 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 “precast foundation”, 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.
  1. Set your precast deck piers in a grid, at roughly three- to four-foot intervals.
  2. Measure your grid diagonally from corner to corner, using a measuring tape.
  3. 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 “how much can my deck hold?” 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 12deck, 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 “how much can my deck hold?” 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
  1. Determine the width and length of the cement slab in inches.
  2. Divide the width by 12 to convert it to feet.
  3. Divide the length by 12 to convert it to feet.
  4. Determine the depth or thickness that is required for the footing in inches.
  5. Multiply the width by the length and then by the depth.