What Is Post And Beam Construction?

Post and beam construction uses metal fasteners, steel brackets, or bolts to hold a framework together. On the other hand, traditional timber frame construction relies on other wood joinery methods, like mortise and tenon.

In this guide, we'll walk you through everything there is to know about post and beam construction. We'll cover how they are assembled, the pros and cons, and how they compare to timber frame construction.

A better understanding of Post And Beam Construction

Post and beam construction is a building method built from the ground up, using vertical and horizontal beams to create a framework. The skeletal framework consists of decking, posts, and beams, supported on a foundation with 23 - 47 inch gaps between the supporting posts.

These aesthetically pleasing, versatile structures suit most weather conditions and terrains. They are often used for homes, barns, or commercial structures throughout the US and Canada.

Predominately constructed from heavy timbers, like oak, Alaskan Yellow Cedar, Western Red Cedar, or California Redwood, a post and beam barn is known for its strength, durability, and rustic aesthetics that stand the test of time.

While lumber framing has been the to-go, modern concrete or steel adaptations to its structural support have been used. Completed structures boast large, open, interior spaces due to fewer load-bearing walls (i.e. posts and beams support the roof), and the overall construction champions energy efficiency.

As mentioned, post and beam construction utilizes metal fasteners, bolts, or steel brackets to secure the framework. This allows for quick assembly compared to other timber frame buildings.

Insightful fact: Post and beam construction dates back around 4,000 years!

Benefits

• Strong and durable
• Weatherproof
• Wood = naturally insulating
• Aesthetically pleasing
• Oak structures can last around 300 years (and are more fire-resistant than steel!)
• Lower labor costs
• Quick installation/assembly (compared to wooden frame builds)
• Requires a lower skill set (when compared to timber frames)
• Eco-friendly choice

Drawbacks

• Susceptible to moisture (steel surfaces prone to rust)
• Wood may suffer from termite/woodworm attacks
• Longer assembly time compared to "mainstream" homes

And what is Timber Frame Construction?

Timber frame construction is a time-tested building method known for its beauty and strength. Timber frames are crafted from solid wood panels that create a traditional, visually appealing, weather-resistant structure.

Timber frame construction uses interlocking joins (i.e. wood-to-wood joints) to achieve superior strength and structural stability. This eliminates the need for metal fasteners. Mortise and tenon joints (with oak pegs) are the strongest joints for timber framing and are precisely milled to achieve a tight fit and "lock" the posts and beams into place.

To the untrained eye, timber frame and post and beam construction may look the same. While both sport exposed beams, the joining between the beams and posts is the key differentiating factor.

The trussed rafters and mortise and tenon joinery require skilled carpentry. This bumps up the price compared to "lower-skill" post and beam construction. The timber framework is pre-cut and prefabricated off-site, allowing for quicker assembly as opposed to "mainstream" builds; however, it usually takes longer to erect than post and beam construction due to specialized joinery.

Timber framing is not only used for residential dwellings but also for barns, hotels, schools, offices, and sporting facilities. And, with the proper construction, it can last for centuries!

Insightful fact: Timber frame construction dates back almost 10,000 years!

Benefits

• Strong and durable
• Wooden frames "give" under loads (e.g. snowfalls, high winds)
• Acoustic benefits
• Superior mortise and tenon joinery
• Weather-proof and waterproof
• Wood is naturally insulating/thermal regulating
• No corrosion
• Customizable floorplans
• Eco-friendly and energy-efficient

Drawbacks

• Higher labor costs due to skilled carpentry
• Wood may be susceptible to wood-boring pests

Some of the Timber Frame Projects that Homestead offers:

• Homes
• Commercial builds
• Barns
• Cabins
• Pavilion Kits

Comparing Post and Beam Construction & Timber Frame Construction.

Post and beam structures have exposed beams, just like timber frame structures. However, their key differentiating factor is how the framework is held together.

Here's a quick breakdown of their similarities and differences.

Similarities

• Crafted from heavy timbers
• Boast exposed beams
• Strong and durable
• Weather-resistant and long-lasting
• Aesthetically pleasing and traditional appearance
• Open floor plans

Differences

Joinery

• Post and beam construction relies on metal fasteners like screws, bolts, and metal connectors to bind the posts and beams together.
• Timber frames showcase traditional wood joinery, like mortise and tenon with oak pegs, where interlocking pieces create a supporting structure without the need for metal.

Construction

• Post and beam construction is built on-site, with the frame gradually rising from the ground up, followed by walls and other elements.
• Timber frames are usually prefabricated off-site and assembled on location, like a giant puzzle.

The right choice depends on your priorities, preferences, and budget. Post and beam might be a good fit if you desire a quicker construction process and potentially lower costs. Timber frames, while potentially more expensive, offer unmatched craftsmanship and a timeless aesthetic.

FAQs

What is the principle of post and beam construction?

In post-and-beam construction, the key idea is to use strong, vertical supports (posts) to hold up the horizontal framework (beams) that create the main structure. These posts typically sit on a foundation for added stability.

What is the spacing for post and beam frames?

The spacing for post and beam structures can range between 2 and 4 feet (23 - 47 inches).

How does wood joinery make a difference?

While there is no "right" or "wrong" way of joining wood, there are a few things to consider when it comes to opting for post and beam construction vs. timber framing. Metal fasteners, as seen in post and beam construction methods, are more susceptible to rust which can cause the joints and structures to loosen over time.

Traditional wood joinery used in timber frame construction creates a much stronger, interlocking system, as the wedged pieces resist pulling forces that create a stiffer structure.

What materials are used for post and beam structures?

Heavy timber such as Alaskan Yellow Cedar, Western Red Cedar, Pine/Spruce, Hemlock, Oak, Douglas Fir/Larch, and California Redwood are commonly used for post and beam structures.

What are beam structures?

"Beams" are horizontal/lateral structures that carry weight-bearing loads across the axis. Imagine a long plank resting on two supports.