Timber Frame Design Basics
The function of a timber frame house, its cost, and the satisfaction people get from it start with the design. With a good initial design concept, the whole building process goes more smoothly.
In most cases, several people work together to achieve the best design. One person might work on the frame, and other people might work on the cabinets and windows - We undertake the frame design.
- A structure needs to be strong to pass onto generations
- Timber sizing needs to be precise so as to calculate for strength and adhere to design and visual presentation
- Each timber member needs to be connected properly so that it will last as long as the material
- A good frame design shows a nice flow of member lines while achieving its structural demands
- If a frame is structurally sound it takes on a “strong” appearance and if not, it may look “weak” – this natural balance is easy to recognize for people (even without timber frame experience)
- We build timber frames not only because they are strong, but also because they are beautiful
- People often say that a frame is the most beautiful right after it is raised because they see the entire structure - this is true
- After the finishing work is applied, some frames lose their visual effect when they are covered with walls, or if posts or beams are hidden - timber design need to take this into consideration
- There are two styles of frames - bent style frames and post and beam
- Post and beam style frames are popular in Japan and Asia
- They can contain a long roof overhang
- A characteristic of this frame is that the corner post goes from the bottom to the top plate. The top beam is also one solid piece. Sometimes a splice joint is used to connect the two pieces together.
- Bent style is more popular in North America and Europe
- Each bent is framed as a solid component, which means that the outside post is one piece and the principal rafter is connected to this post
- This is a very efficient way of raising a frame
- It is designed to cover the timber frame with exterior wall, and often people use an SIP panel to maximize the insulation value
- However, mixing these two concepts without careful thought can cause difficulty in assembling
- When engineers face structural difficulties, it is easy to turn to steel connections to achieve the required strength
- Steel connection tends to be applied because of a lack of knowledge with respect to other connection methods
- Before deciding on steel, we see what we can do to make the structure work with wood joinery
- Most buildings built in the past few centuries were built this way, and many of them are still standing — and in good shape
- When wood shrinks, wood joinery often works better as some joints become tighter
- Steel connections, on the other hand, become loose after wood shrinkage
- Wood-to-wood connections work well because they allow for movement.
- Steel fasteners are very strong in a tension joint.
- When we use steel fasteners, we design the fastener so it will work well with the wood’s character
Pegs and Splines
- Using pegs to secure the wood joinery is what makes timber frames unique
- Using oak splines for a tension joint is a traditional method of timber framing
- Tension connections require strength - That is often where steel replace the wood joinery
- We use oak for this work - The tenons and mortises are as secure as we can make them with these oak pegs
- Understanding how these pegs work and their strength is important in building timber frames
- Using steel fasteners has become more popular and is our choice for certain connections
- The combination of steel and wood is beautiful
- Steel design has became one of our service offerings
- CNC steel fabrication brings our design concept to the next level