Deck Framing
Deck Beam Span Chart: Maximum Beam Spans, Post Spacing & Structural Load Explained
Deck beam span determines how far a beam can safely extend between support posts while carrying the joists and deck loads above it.
But beam span is not determined by beam size alone. A double 2×10 supporting short joists may be permitted to span substantially farther than the same double 2×10 supporting long joists or a large joist cantilever.
To determine how far a deck beam can span, you need to know:
- beam size and number of plies
- lumber species and grade
- joist span
- joist cantilever
- beam span between posts
- design loading
- post and footing layout
Quick Answer: There is no universal span for a double 2×8, double 2×10, or double 2×12 deck beam. The allowable span changes with the load delivered by the joists. Use the applicable beam-span table for the actual beam size, species, joist span, cantilever, and design load.
Framing Hub → Beams → Beam Span
This is the numeric lookup page for how far a selected deck beam can span between supports.
Start with the Deck Beam Size Chart if you still need to choose a beam configuration,
or return to the Deck Framing Guide for the complete structural load path.
Quick Deck Beam Span Chart
The chart below gives a practical example of how dramatically beam span changes as the joist span increases.
These values reproduce the Southern Pine, No. 2 grade, 40 psf live-load / 10 psf dead-load prescriptive beam-table case used in the 2021 IRC deck provisions. Wet-service adjustment is included in the table assumptions. They are useful as a planning lookup, but the code edition and amendments adopted by your jurisdiction control.
| Beam Size |
6-ft Joist Span |
8-ft Joist Span |
10-ft Joist Span |
12-ft Joist Span |
14-ft Joist Span |
16-ft Joist Span |
| Double 2×6 |
6′-11″ |
5′-11″ |
5′-4″ |
4′-10″ |
4′-6″ |
4′-3″ |
| Double 2×8 |
8′-9″ |
7′-7″ |
6′-9″ |
6′-2″ |
5′-9″ |
5′-4″ |
| Double 2×10 |
10′-4″ |
9′-0″ |
8′-0″ |
7′-4″ |
6′-9″ |
6′-4″ |
| Double 2×12 |
12′-2″ |
10′-7″ |
9′-5″ |
8′-7″ |
8′-0″ |
7′-5″ |
| Triple 2×8 |
10′-11″ |
9′-6″ |
8′-6″ |
7′-9″ |
7′-2″ |
6′-8″ |
| Triple 2×10 |
13′-0″ |
11′-2″ |
10′-0″ |
9′-2″ |
8′-6″ |
7′-11″ |
| Triple 2×12 |
15′-3″ |
13′-3″ |
11′-10″ |
10′-9″ |
10′-0″ |
9′-4″ |
Important: The table above is a Southern Pine planning lookup under the stated 2021 IRC table assumptions. Other species, grades, snow/live loads, effective joist spans, local code editions, and engineered conditions can produce different allowable spans. Interpolation may be permitted by the applicable table; extrapolation is not.
The Most Important Thing to Understand About Beam Span
A beam does not carry the same load on every deck.
The longer the joists supported by the beam, the more deck area feeds load into that beam.
That is why the same beam size has multiple allowable spans in a code table.
Short joist span → smaller beam load → longer possible beam span
Long joist span → larger beam load → shorter allowable beam span
This is the reason a statement such as “a double 2×10 can span 10 feet” is incomplete.
It might under one framing configuration. Under another, the permitted span can be several feet shorter.
INTERACTIVE LOAD VISUAL
See Why the Same Beam Has Different Span Limits
Keep the beam the same and change only the joist span. As the joists extend farther from their support, more deck area contributes load to the beam, and the maximum permitted beam span becomes shorter.
Example conditions: Double 2×10 Southern Pine beam, No. 2 grade, wet-service factor included, 40 psf live load and 10 psf dead load. The values below are prescriptive beam-table examples, not universal beam spans.
Structural note: This is a simplified teaching diagram, not a framing design. Actual beam-table selection must use the applicable code edition, effective deck joist span, joist cantilever condition, lumber species and grade, loading criteria, beam configuration, and local amendments.
For projects subject to snow loading or different design criteria, use the applicable beam table rather than the 40 psf live-load example shown here.
What Is a Deck Beam?
A deck beam is a horizontal structural member that collects load from multiple joists and transfers that load into posts and foundations below.
On a conventional ledger-attached deck:
decking → joists → beam → posts → footings → soil
Because many joists can bear on the same beam, the beam carries a substantial portion of the deck load.
That makes beam sizing one of the most important structural decisions in the entire framing system.
What Is Deck Beam Span?
Deck beam span is the horizontal distance between the beam’s structural bearing locations.
On a conventional post-supported beam, that generally means the distance between supporting posts.
Beam span ≠ beam length.
A 20-foot-long beam supported by four posts does not have a 20-foot structural span. It has multiple shorter spans between those posts.
This distinction becomes especially important when the beam cantilevers past the outside posts.
Beam Span vs. Post Spacing
For a conventional post-and-beam deck, beam span and post spacing are directly related.
If posts move farther apart:
- beam span increases
- beam bending increases
- deflection can increase
- a larger or stronger beam may be required
- each post and footing may carry more tributary load
If posts move closer together:
- beam spans become shorter
- smaller beams may become possible
- more posts and footings may be required
See our Deck Post Spacing Chart for the support-layout side of this decision.
Why Joist Span Controls Beam Span
The beam does not know the overall square footage of the deck.
What matters structurally is the load delivered to the beam.
For a simple ledger-and-beam deck, increasing the distance between the ledger and beam increases the deck area supported by that beam.
| Change |
Effect on Beam |
| Shorter joist span |
Lower beam reaction |
| Longer joist span |
Higher beam reaction |
| Larger joist cantilever |
Higher beam reaction |
| Larger beam |
Potentially longer allowable span |
| Closer posts |
Shorter required beam span |
Related:
Deck Joist Span Chart
and
Deck Joist Spacing Guide.
What Is Tributary Load?
Tributary area is the portion of the deck whose load is transferred into a particular structural member. For this page, use the effective deck joist span defined by the applicable beam table rather than substituting a homemade “half the joist span” rule.
For a beam, joist geometry is one of the biggest contributors to that load.
If the beam supports a wider section of deck, it carries more load.
This is why beam span and joist span cannot be selected independently.
The beam, joists, posts, and footings are part of one structural system.
Changing one component can change the load imposed on several others.
Use our
Deck Tributary Area
to see how deck area is distributed into the beam, posts, and footings.
How to Use a Deck Beam Span Chart Correctly
Use this sequence instead of starting with a beam size and guessing how far it can span.
- Determine the deck design load.
- Identify the lumber species and grade.
- Determine the actual joist span.
- Include any joist cantilever.
- Select the proposed beam size and number of plies.
- Find the allowable beam span for that exact combination.
- Lay out the posts so no beam span exceeds the permitted value.
- Size the posts and footings for the resulting tributary loads.
- Verify the design against your locally adopted code.
Do not start with: “I want my posts 10 feet apart. What beam should I use?”
Start with the deck loads and framing geometry, then determine which beam configurations permit the desired span.
How Far Can a Double 2×8 Deck Beam Span?
There is no single answer.
Using the Southern Pine 40 psf example above, a double 2×8 spans approximately:
- 8′-9″ with a 6-ft effective joist span
- 7′-7″ with an 8-ft effective joist span
- 6′-9″ with a 10-ft effective joist span
- 6′-2″ with a 12-ft effective joist span
- 5′-9″ with a 14-ft effective joist span
That is a difference of several feet even though the beam itself never changed.
How Far Can a Double 2×10 Deck Beam Span?
A double 2×10 is a common residential beam, but its allowable span still depends heavily on the deck it supports.
For Southern Pine under the example assumptions:
- 6-ft joist span: 10′-4″
- 8-ft joist span: 9′-0″
- 10-ft joist span: 8′-0″
- 12-ft joist span: 7′-4″
- 14-ft joist span: 6′-9″
- 16-ft joist span: 6′-4″
This is why we no longer recommend using “9–10 feet” as a generic span for a double 2×10. The actual allowable span is load-dependent.
How Far Can a Double 2×12 Deck Beam Span?
A double 2×12 can span farther than smaller two-ply beams under comparable conditions, but the joist load still matters.
For the same Southern Pine example:
- 6-ft joist span: 12′-2″
- 8-ft joist span: 10′-7″
- 10-ft joist span: 9′-5″
- 12-ft joist span: 8′-7″
- 14-ft joist span: 8′-0″
- 16-ft joist span: 7′-5″
A deeper beam can increase allowable post spacing, but that does not automatically make it the most economical framing solution.
How Far Can a Triple 2×12 Beam Span?
Triple 2×12 beams can provide substantially longer spans in suitable residential configurations.
Under the Southern Pine example:
- 6-ft joist span: 15′-3″
- 8-ft joist span: 13′-3″
- 10-ft joist span: 11′-10″
- 12-ft joist span: 10′-9″
- 14-ft joist span: 10′-0″
- 16-ft joist span: 9′-4″
Triple beams are therefore useful when post placement is constrained, but the tradeoff is greater material weight, cost, handling difficulty, and load at the remaining supports.
Double vs. Triple Deck Beams
| Factor |
Double Beam |
Triple Beam |
| Material |
Less lumber |
More lumber |
| Weight |
Lower |
Higher |
| Typical span capability |
Shorter |
Longer |
| Potential post count |
Higher |
Potentially lower |
| Footing reactions |
Distributed across more supports where posts are closer |
Can be higher where supports are farther apart |
| Installation difficulty |
Easier |
More difficult |
More beam is not automatically better. The most efficient deck balances beam size, post spacing, footing size, labor, and the desired layout.
Built-Up Deck Beam Requirements
A built-up beam only performs as intended when its individual plies are connected and supported correctly.
Under the 2021 IRC prescriptive deck provisions used as the basis for this lookup, beam plies are fastened with at least two rows of 10d (3-inch × 0.128-inch) nails at 16 inches on center along each edge. Multi-span built-up beam splice details must follow the applicable bearing and continuity provisions.
Important principles include:
- individual plies must be properly fastened together
- beam plies must have proper bearing
- beam splices must occur at approved bearing locations
- a member supporting a cantilever must remain continuous across that bearing location
- the beam must be restrained against lateral displacement
Do not treat several boards placed beside each other as a built-up beam unless they are assembled according to the applicable framing requirements.
Fastener type matters too. A screw marketed as “structural” is not automatically interchangeable with the fastener prescribed by the code or specified by a proprietary connector manufacturer. See our
Deck Screws vs. Structural Screws Guide
for the differences between ordinary deck screws, structural wood screws, and connector fasteners.
Beam Bearing: How the Beam Should Sit on the Post
Modern prescriptive deck framing requires the beam to have actual structural bearing at its support.
The beam should not simply be bolted to the side of a post and depend on those bolts alone to carry the vertical gravity load.
Common compliant approaches include:
- beam bearing directly on top of the post with an approved post cap or connector
- a properly notched post that provides beam bearing where permitted
- another approved structural support detail
The IRC deck provisions require at least 1-1/2 inches of bearing on wood or metal and at least 3 inches on concrete or masonry for the full beam width, subject to the applicable edition and connection detail.
The connection has two jobs: provide vertical bearing and prevent lateral displacement.
Next structural decision: Once the beam size and support locations are established, verify how the beam transfers its load into the post. See our
Deck Post-to-Beam Connections Guide
for beam bearing, post notches, post caps, built-up beams, splices, and connection details.
Can a Deck Beam Be Bolted to the Side of a Post?
Not as a conventional gravity-load support detail where the beam is simply hanging beside the post and relying on through-bolts to carry the beam load.
The beam needs approved bearing support.
This is an important distinction because many older decks were built with beams bolted to the sides of posts.
A manufactured structural connection may be used where specifically approved and installed for the beam and post configuration, but the connection must provide the required load path.
For common bearing, notching, post-cap, and connection configurations, see our
Deck Post-to-Beam Connections Guide.
Why 6×6 Deck Posts Are So Common
6×6 posts are extremely common on modern residential decks because they provide substantial capacity, useful height limits, a wider bearing surface, and convenient compatibility with many beam-to-post connections.
However, 6×6 is not a universal code requirement for every deck.
Current prescriptive post tables can permit 4×4, 4×6, 6×6, and other post sizes under different combinations of species, post height, tributary area, and loading.
Do not choose post size from habit alone. Post size is another load-dependent structural decision.
Use our
Deck Post Size Chart
to see how post size changes with height, tributary area, species, and loading. Then use the
Deck Post Spacing Chart
to connect the post layout back to the allowable beam spans above.
Drop Beam vs. Flush Beam
Joists Bear Above
Drop Beam
A drop beam sits beneath the joists.
- joists bear directly on the beam
- joists can potentially cantilever beyond it
- load path is easy to understand
- often simplifies framing
Joists Frame Into Beam
Flush Beam
A flush beam is installed at the same elevation as the joists.
- joists terminate at the beam
- approved joist hangers transfer the reactions
- useful where framing depth is limited
- more dependent on connector detailing
Both configurations can be structurally valid. The important difference is how the joists transfer their loads into the beam.
Beam Cantilever: How Far Can a Beam Extend Past a Post?
A beam does not necessarily have to terminate directly above the outside post.
The prescriptive IRC deck provisions used here permit a beam to cantilever at an end up to one-fourth of the actual adjacent beam span. This is a limit, not an automatic design allowance for every nonprescriptive beam or connection.
| Actual Adjacent Beam Span |
Maximum 1/4 Cantilever |
| 6 ft |
1 ft 6 in |
| 8 ft |
2 ft |
| 10 ft |
2 ft 6 in |
| 12 ft |
3 ft |
Use the adjacent beam span—not the total beam length.
And verify that the beam is permitted to span that distance before calculating the cantilever.
See our Deck Cantilever Guide for joist and beam cantilever rules, lookup tables, and examples.
Joist Cantilever Can Reduce Beam Span
This is an important beam-design concept that is often missed.
When joists extend beyond the beam, the overhanging deck area still places load on the beam.
That means a large joist cantilever can reduce the allowable beam span compared with the same joist back span with no cantilever.
Cantilevered deck area is not free structural area.
When using current beam tables, make sure the selected column represents the actual joist span and cantilever condition.
How Many Posts Does a Beam Need?
Once you know the maximum allowable beam span, you can begin laying out the posts.
For a simplified straight beam with posts at both ends, no beam cantilever, and equal-or-shorter spans:
Required beam spans = Round Up (Beam Length ÷ Allowable Beam Span)
Posts = Beam Spans + 1
Example
Suppose the beam is 20 feet long and your approved beam configuration allows an 8-foot maximum span.
20 ÷ 8 = 2.5
Round up to 3 structural spans.
3 spans require 4 supports:
Post — Span — Post — Span — Post — Span — Post
For the next step, use our
How Many Deck Posts Do I Need?
guide to convert allowable beam span into a support layout. Then use
How Many Footings Do I Need for a Deck?
to carry that layout into the foundation plan.
Example: Beam Design for a 12×16 Attached Deck
Suppose a deck is 12 feet deep and 16 feet wide.
The joists run perpendicular to the house and the exterior beam runs parallel to the house.
A common first assumption would be:
- approximately 12-ft joist back span
- 16-ft beam length
- one exterior post-supported beam
Now compare beam options using the appropriate 12-ft joist-span column.
Under the Southern Pine 40 psf example:
| Beam |
Example Maximum Beam Span |
| Double 2×8 |
6′-2″ |
| Double 2×10 |
7′-4″ |
| Double 2×12 |
8′-7″ |
| Triple 2×10 |
9′-2″ |
| Triple 2×12 |
10′-9″ |
Notice how different that is from simply assuming “posts every 8–10 feet.”
Whether 8-foot, 9-foot, or 10-foot post spacing works depends on the selected beam—not the deck dimensions alone.
Example limitation: This comparison assumes the 12-ft effective-joist-span column and the stated Southern Pine load case. It is not a complete permit design; post reactions, footing size, connections, cantilevers, and local loading still require verification.
Does Joist Spacing Affect Beam Span?
Joist spacing strongly affects joist design, but beam tables are generally based on the total deck area and load being transferred to the beam rather than simply counting the individual joists.
The more important beam inputs are typically the effective joist span or tributary width, joist cantilever, beam size, beam species, and design loading.
However, joist spacing still matters to the overall deck because the joists themselves must satisfy their own span limits and the decking must be supported at the required spacing.
How Snow Load Affects Deck Beam Span
The beam table used for one climate may not apply to another.
Higher design loads increase beam demand and generally reduce allowable spans.
This is particularly important in locations with substantial ground snow loads or locally required loading criteria.
Do not automatically use a 40 psf beam table if your project requires a higher design load.
Your local building department can identify the load criteria and code edition applicable to the project.
Species & Grade Matter
Two beams with identical dimensions can have different allowable spans if they are made from different lumber species or grades.
Common deck span tables separate structural values for species groups such as:
- Southern Pine
- Douglas Fir-Larch
- Hem-Fir
- Spruce-Pine-Fir
- Western Cedars
- Redwood
Check the lumber grade stamp before choosing a span-table row.
Do not use the Southern Pine example chart above for another species without verifying the applicable table.
Single-Beam vs. Multi-Beam Deck Layouts
Simple Structure
Single Exterior Beam
- fewer beam lines
- fewer posts and footings
- longer joist spans
- higher load on the exterior beam
Shorter Spans
Multiple Beam Lines
- shorter joist spans
- load distributed among more supports
- potentially smaller beam requirements
- more posts and footings
Adding another beam can sometimes reduce the size required for other framing members, but it also adds foundation work.
Beam Span vs. Deck Cost
Longer beam spans are not automatically cheaper.
| Strategy |
Potential Benefit |
Potential Cost |
| Longer spans |
Fewer posts and footings |
Larger, heavier beam |
| Shorter spans |
Smaller beam may work |
More posts and footings |
| Additional beam line |
Shorter joist spans and improved stiffness |
More framing and foundations |
The cheapest beam is not necessarily the cheapest deck.
The economical solution is the combination of beam size, post count, footing size, labor, excavation, and desired deck layout that works together.
Related:
Deck Framing Cost Guide.
Common Deck Beam Mistakes
1. Using One Span Number for Every Double 2×10
Beam span depends on the deck area and load feeding the beam.
2. Choosing Post Spacing First
Desired post spacing does not determine what the beam can structurally span.
3. Ignoring Joist Cantilever
Cantilevered joists can add substantial load to the beam.
4. Ignoring Lumber Species
Span tables are species-specific.
5. Using the Wrong Load Table
Snow and other locally required loads can change the allowable beam span.
6. Side-Bolting a Beam to a Post Without Bearing
The beam needs an approved load path into the post—not simply fasteners carrying the gravity load in shear.
7. Splicing Built-Up Beam Plies Away From Bearing
Beam splice locations must follow the applicable structural details.
8. Maximizing Every Span
A deck can satisfy maximum structural span limits and still feel less stiff than a design using shorter spans.
Signs an Existing Deck Beam Needs Attention
Potential warning signs include:
- visible beam sagging
- splits or significant deterioration
- beam movement at posts
- unsupported or poorly supported splices
- posts leaning beneath the beam
- loose or corroded connectors
- significant deck bounce or movement
- beam ends losing adequate bearing
A visible problem does not automatically identify the underlying cause. Beam movement can originate from the beam, posts, footings, connections, joists, ledger, or a combination of components.
For an existing structure, see our
Deck Inspection Checklist
and
Deck Repair vs. Replace Guide.
Beam size and allowable span come from the applicable structural tables or engineering—not from a tool. But once the framing layout is established, a few well-chosen tools make it easier to transfer that design accurately to the site.
These are the tools we would prioritize specifically for beam, post, and framing layout.
As an Amazon Associate, The Backyard Standard earns from qualifying purchases, at no additional cost to you.
Backyard Standard Pick
Bosch BLAZE Pro GLM165-40 Laser Measure
Best beam-layout upgrade: The Bosch BLAZE makes it faster to check overall deck dimensions, beam runs, post-to-post distances, and other longer measurements before transferring precise layout marks with a tape.
Best for: Long deck dimensions, beam layout, post locations, estimating, and layout verification.
Buy if: You are repeatedly measuring longer framing dimensions or checking an existing deck.
Skip if: You only need a few short measurements and already own a dependable tape measure.
Why it earns the top spot
- 165-ft measuring range
- compact enough for a tool bag
- fast for repeated long measurements
- useful well beyond one deck project
Know before buying
- red laser visibility can decrease in bright outdoor light
- it does not replace a tape for transferring cut marks
Check Bosch GLM165-40 on Amazon →
The laser measure is the specialized tool we would prioritize for this stage of the project. The remaining recommendations are lower-cost tools that earn their place through repeated everyday use.
Essential
STANLEY 30-Ft Tape Measure
For beam layout, post spacing, offsets, cut marks, and everyday framing measurements. The 30-ft reach is particularly useful on deck-sized layouts.
Check on Amazon →
Best Value
Swanson 7-Inch Speed Square
A high-value framing tool for square cut lines, layout marks, angle work, and guiding common framing cuts throughout the project.
Check on Amazon →
Useful Add-On
Pica-Dry Longlife Automatic Pencil
A reusable jobsite marking pencil with replaceable lead, an integrated sharpener, and a holster that makes repeated framing layout more convenient.
Check on Amazon →
Rent rather than buy: A rotary or grade laser can be extremely useful for transferring consistent beam, post, and footing elevations across a larger site. For most homeowners building one residential deck, professional-grade rotary equipment makes more sense to rent than buy.
See our
Deck Building Tools Guide
for our complete buy, rent, and skip recommendations.
Structural fastener note: Do not substitute a generic screw for an IRC-prescribed connection or proprietary connector fastener simply because the package says “structural.”
See
Deck Screws vs. Structural Screws
before choosing fasteners for structural framing.
Frequently Asked Questions
How far can a deck beam span?
Deck beam span depends on beam size, number of plies, species, joist span, joist cantilever, and design loading. There is no universal beam span that applies to every residential deck.
How far can a double 2×8 deck beam span?
Under the Southern Pine 40 psf example in this guide, a double 2×8 ranges from about 8′-9″ with a 6-foot joist span to about 5′-4″ with a 16-foot joist span. Other species and loading conditions differ.
How far can a double 2×10 deck beam span?
Under the same Southern Pine example, a double 2×10 ranges from approximately 10′-4″ at a 6-foot joist span to about 6′-4″ at a 16-foot joist span.
How far can a double 2×12 deck beam span?
Under the Southern Pine example, a double 2×12 ranges from approximately 12′-2″ with a 6-foot joist span to approximately 7′-5″ with a 16-foot effective joist span.
How far can a triple 2×12 deck beam span?
Under the same assumptions, a triple 2×12 ranges from approximately 15′-3″ at a 6-foot joist span to about 9′-4″ at a 16-foot joist span.
Does joist span affect beam span?
Yes. Longer joists generally deliver more load to the supporting beam, which reduces the allowable beam span for the same beam size.
Does joist cantilever affect beam span?
Yes. Cantilevered deck area still transfers load into the beam. A larger joist cantilever can therefore reduce allowable beam span.
Is beam span the same as post spacing?
On a conventional straight post-supported beam, the structural beam span is the distance between bearing locations, so it closely corresponds to post spacing.
Can a deck beam cantilever past a post?
Yes. Under current prescriptive IRC deck provisions, a beam can cantilever beyond a bearing location up to one-fourth of the actual adjacent beam span, subject to the remaining framing requirements.
Can a deck beam be bolted to the side of a post?
A conventional beam should not rely only on through-bolts through the side of a post to carry its gravity load. The beam needs approved bearing support and lateral restraint.
Are triple beams always better than double beams?
No. Triple beams can provide greater capacity and longer spans, but they also cost more, weigh more, and can increase the loads carried by fewer posts and footings.
Do I need 6×6 posts under a deck beam?
Not universally. Post size depends on post species, height, tributary area, loading, and the applicable code table. 6×6 posts are common, but smaller posts can still be permitted in some prescriptive conditions.
Should I use the maximum beam span allowed?
Not necessarily. Maximum code span is a structural limit, not necessarily the ideal stiffness target. Shorter spans can reduce deflection and create a stiffer-feeling deck.
Technical References
Technical references reviewed: September 2026
Code note: The numeric Southern Pine lookup on this page is explicitly tied to the 2021 IRC R507.5 40 psf live-load table case rather than being presented as a universal “2026 code” table. The IRC is a model code; local adoption, amendments, loads, species, grade, and project geometry control.
The Backyard Standard Final Answer
A deck beam’s maximum span cannot be determined from beam size alone.
The correct beam span depends on the structural system above and below it:
joists → beam → posts → footings → soil.
First determine the joist span and cantilever feeding the beam. Then select the beam size, species, and number of plies. Use the appropriate span table to determine how far that beam can extend between supports.
Only after that should you finalize post spacing.
The simplest way to remember it:
Longer joists load the beam more heavily. Heavier beam loads mean shorter allowable beam spans.
Continue with our
Deck Beam Size Chart,
Deck Post Spacing Chart,
Deck Post Size Chart,
Deck Post-to-Beam Connections Guide,
Deck Cantilever Guide,
and
Deck Footing Count Guide
to design the rest of the structural support system.
Framing Hub
Deck Framing Guide
Return to the full structural load path and framing decision sequence.
Beam Assembly
Deck Beam Splice Guide
See how built-up beam continuity, bearing, and splice locations work together.
Beam Sizing
Deck Beam Size Chart
Compare common built-up beam sizes and determine which configurations fit your structural layout.
Joists
Deck Joist Span Chart
See how joist length affects the load delivered to the beam and support system.
Post Layout
Deck Post Spacing Chart
Connect allowable beam span to the spacing between structural supports.
Post Count
How Many Deck Posts Do I Need?
Turn allowable beam span into a practical post layout for the beam line.
Post Sizing
Deck Post Size Chart
See how height, tributary area, species, and loading affect post size.
Connections
Deck Post-to-Beam Connections
Understand beam bearing, post notches, post caps, splices, and the load path at each support.
Load Path
Deck Tributary Area
See how deck area distributes load into beams, posts, and footings.
Cantilevers
Deck Cantilever Guide
Understand joist and beam cantilevers and how they change structural loading.
Footing Count
How Many Footings Do I Need?
Carry the beam and post layout into the foundation plan.
Footing Size
Deck Footing Size Chart
See how tributary load and soil-bearing capacity affect footing size.
System Design
Deck Framing Layout
Understand how joists, beams, posts, footings, and the ledger work together.
Tools
Deck Building Tools
See which layout and framing tools are worth buying, renting, or skipping.
