Timber Frame Truss Styles

The basis of heavy truss design concepts for post and beam construction of trusses.

Usage of timber trusses is highly dependent on the house (or structure) square footage, roof lines (both pitch and context of other rooflines) overall spans, design preferences and structural requirements. Each heavy timber truss style can be modified heavily, but these classifications will fit most truss designs.

Although it may seem difficult, it’s actually pretty easy to get started on including gorgeous exposed wood trusses in your project. The first step is to review potential truss beam styles and choose ones that catch your eye.

Simple Truss

Attractive traditional truss, best used in smaller applications. The size of the simple truss is limited to the load bearing capacity of its diagonal members, since it doesn’t have webs; this means your common simple truss span will max out around 30′.

Scissor Truss

A variable slope timber truss with multiple webs and a lot of flexibility. The scissor truss design still fits in well with modern building styles – especially useful for roofs with different opposing slopes.

Queen Truss

The queen truss frame calls to mind Craftsman or European timber framing design. This special truss design also balances well if you have a tall space to fill. Also, the queen truss allows for display or storage space within a timber truss.

King Truss

A popular and well-liked timber truss style for timber framing – with wide variety of web styles etc. You will need to consider factors such as wall height, room volume, truss spacing and roof slope to arrive at the best variation of the truss for your situation.

Hammer Beam Truss

This heavy truss style can be used for bigger applications like a church, park pavilion or indoor pool space. The Hammer Beam Truss is not a gambrel truss, instead it’s got a strong, solid look, perfect for large spaces.

Arched Truss

Top cords are not arched but the bottom cord and webs can be placed in a wide variety of arched truss styles. Comes out of the Classical, Euro, Traditional and in some cases Rustic timber frame designs.

Cable Truss

This is a versatile truss that fits well in many situations. Sometimes a full timber truss is too bulky or an industrial timber frame look is desired. This truss can even add a modern touch to old farmhouse for an eclectic aesthetic.

Mono Truss

The mono truss can be easily adjusted to be a scissor mono truss if desired. Space intimacy is the biggest reason to slope the bottom chord of a mono timber frame truss. Can be used in a vaulted ceiling that terminates at the beginning of an upper level or overlooking a great room.

Box Truss

This heavy roof truss design can fit into both Traditional and Modern style homes, businesses, and shops. The Box Truss can help fill up space in higher ceilings and provide an orderly and strong structure.

3 Distinct Heavy Timber Truss Styles

and how to find your unique truss.

 

To find the right truss for your situation, the biggest factors to consider are:

A) Span and load bearing capacity.

B) Style aesthetics and complimenting your home style theme.

C) Investment rational.

In the following examples I will only speak to points A and B. Your investment rational is not my bailiwick! But in a general investment sort of way, people generally get a higher sale price for a home with artistically designed timber framing, should they choose to sell. They also tend to sell faster, as one would expect from homes that are aesthetically pleasing. And by far, the big payoff is enjoyment- from simple timber living with coffee in the morning to fun memorable gatherings with family and friends.

DISCLAIMER: In speaking to points A and B, I am not a certified engineer nor a soothsayer, able to divine the nuanced way you interpret different style descriptions and adjectives. But consider these descriptions as rudimentary guidelines built from intuition based on years of construction experience and design style communication with clients.

King Truss

The king truss is probably the most common used style of exposed timber trusses. There is an explanation for this- Timeless Geometric Beauty! It is a cross cultural gem that can really be adapted to fit any style.

timber truss king post

You can use the arched bottom timbers and curved webs increase the elegance factor. The Timber King Truss works best with Rustic, Traditional, Classic, and Euro Timber styles. Although I’ve had the opportunity to work with an old style timber king trusses on a restoration project which used an iron rod as the king post. While this project was very rustic, this king truss variation could easily compliment a modern style well.

A common mistake you’ll want to avoid if you choose a king truss style, is positioning the angle of the webs 90 degrees or perpendicular to the sloped/top beams. This is a mistake we see repeated often, probably because it seems easy and natural to align the webs at right angles to the top cords, but it really kills the balance- the center of the truss will appear pinched or cramped, especially so with the lower pitched trusses.

Note: If the webs are eliminated, it is still a king truss, as it utilizes a center king post.

I believe it is better to align the webs by eye to achieve the best balance- the same principal applies when you are deciding how much arch to apply or how much to raise the bottom horizontal truss member if your criteria so dictates- you will be working with factors such as wall height, room volume, truss spacing and roof slope to arrive at the best decision for your timber truss.

timber frame patio porch

Regarding load bearing capacity, it is relatively easy to span 30’ with timber king trusses spaced 12’ apart. Certain king truss joinery is achievable at 30’ without hidden metal connectors to address the tension loading. But, timber king trusses spaced 20’ apart, spanning 40’ are significantly more difficult, still achievable.

Queen Truss

What is special about a queen truss? The most significant aspect is the kind of boxy shape it creates in the center of the truss. The timber Queen truss aligns most closely with the Craftsman style… Can you keep a secret? Most often, the timber Queen trust isn’t a truss at all, but it is simply post and beam loading. Especially with the low roof slopes associated with the Craftsman style. Even when used in the euro style steep rough applications, the Queen posts simply reduce rafter spans. History is rich with old post and beam buildings 40’, 50’ and 60′ wide built with single or double supporting posts from the floor at strategic locations. This is a classic example of post and beam construction where simple span beams support the loading.

queen truss post and beam timber frame

So what is a real truss? Very simply, a real truss uses tension to create load bearing capacity. (See Avoid 98lb weakling article for further clarity.) When the Queen truss is used as a genuine full span truss, the Queen post provides aesthetic value only. Therefore the Queen truss has the same limitations as the simple truss. If one were to add diagonal bracing to the lower triangles, one could achieve an attic truss made by many dimensional 2X lumber truss manufacturers today.

queen truss

But it is rather unattractive geometry, in my opinion. I’ve seen pragmatic use of the Queen truss used in a Rustic style where the “attic box”, created by the spread out queen posts, was intended to display an old handmade canoe, naturally resting in the space overhead.

KEY POINT- Your creativity and imagination are the only real limiting factors to getting what you
want!

Scissor Truss

Before we get into the characteristics of scissor trusses, I want to call your attention to the Mystery of the Disappearing Scissor Truss Massing. I first became aware of this problem, working with entries or back patios where the builder wanted to use decorative timbers underneath standard pre-manufactured scissor trusses to simplify logistics or save money.

scissor truss post and beam timber frame

It was very puzzling. No matter what timber design I would try, the massing would always feel wonky. I finally figured out that it was the imbalance of the scissor gable end truss above.

This was messing with the timber balance and creating the “crooked smile” I was struggling to
correct. Because the center of the GE scissor truss has most of the mass and the narrow bottom ends has virtually no mass, it creates a disappearing effect. With this application of scissor trusses above a porch or patio, the imbalance of scissor truss geometry is acutely visible.

The fix is to counterbalance the imbalance with more timber mass at the narrow ends of the pre-manufactured truss. There are various ways to achieve this, but the most elegant and simple fix is to install tapered timber rafters underneath the GE scissor truss. Narrow the top and fat at the bottom… and Voila! Problem fixed! You might be tempted to save time and just install rafters without the taper. Don’t do it. The imbalance will remain unchanged.

If you were to remove the pre-manufactured trusses and use a timber truss, this problem of disappearing mass is much harder to spot. Bigger timber top and bottom chords coming together at the bottom of the truss results in substantially more mass. And the open truss effect at the center has much less visual mass than does a closed gable end scissor truss. All this combined with the distracting effect of beautiful wood, interlocking pieces and intriguing joinery, will generally solve the case of disappearing mass associated with scissor truss geometry.

Another challenge unique to timber scissor trusses used in a free standing application where lateral bracing is required, is the difficulty getting knee braces or diagonal support beams to look good. Many people end up using concrete, stone or brick pillars to address lateral strength in situations like this. Just keep it in mind as you choose the right timber truss style for your situation.

Now, let’s get into the characteristics of this truss which can be modified in many ways to good effect. In general the timber scissor truss compliments Euro Rustic and Modern styles the best.

And even though a person attracted to the pragmatic Craftsman style would likely be attracted to the scissor timber truss, the shallow roof slopes consistent with Craftsman Style do not work well. Especially for bigger truss spans. And in general with trusses, the steeper the roof slope is, the stronger the truss. It is all about tension loading.

Speaking of pragmatic, using a timber scissor truss is a practical way to achieve a higher ceiling. Today you might see this over a sport court where the extra height allows for high flying balls, while keeping the roof eaves lower for better weather protection. In some cases it simply gives more head room. Back in the old days, the timber scissor truss was often used to give cathedral ceilings an even higher feel.

You can see an example of a 50×39 timber scissor truss we crafted a while back which gave necessary head room and a higher feel:

scissor truss man cave timber frame

The peak was offset because of the different wall heights. You will notice metal plates and bolts used to address the substantial tension loads. They could have been hidden, but the owner like the strong look of the big black steel plates. If you want to avoid using any metal, double bottom chords sandwiching the top chords give you the most wood to work with for addressing the tension loads. Double cop top cords might be used in a lodge where heavy snow loads are expected. Both variations give a stout lodge look and feel. Another option you have at your disposal is to integrate arches into your timber scissor truss.

There are various ways to accomplish this, but the most popular timber scissor truss we manufacture is often called an arched king truss. (King truss with arched bottom chords.) In fact, so many people, professionals and lay people alike, use the technically incorrect name of Arched King Truss, that we use the same name with our communication! Let Webster fight that battle! (See our description of King Trusses. Arched bottom chords are listed as an option to add elegance.) But structural engineering addresses the tension loading the same, whether the bottom chords are arched or straight. But however you refer to this timber truss, it opens a plethora of ways you can influence the look and feel of your remodel, home, office, etc.

Another unique option is to mix the Queen truss concept and arched beams with the scissors truss. Basically you start with a scissor truss and then add Queen post about 1/4 span from each end. (But don’t just run with 25% of total span! Always align exact location by eye.) One can then add an arch beam starting higher up on the Queen post, connecting with the center king post. In this case, a wrought iron tie-rod would need to be added to the bottom of the Queen posts to achieve adequate resistance to tension loading. This modified timber scissor truss is a very unique truss and feels like an elegant throw-back to castle days.

Flexibility in Truss Frame Choices

Finding your unique roof truss style is both rewarding and fun. It will have a large impact on how your whole space and square footage feels. As you plan a timbered living space, you will continually gain more insight into what you love, and what looks best in your living quarters.

These are not your average ‘framer’ wood trusses. These provide the exposed truss experience that signifies such strength, whether you’re sticking with straight timbers, or going with more of a curved look…curved arches, curved braces etc. Keep in mind though, not to get too set on a certain design, because building practicality always influences the truss design you end up choosing.. In some cases, building codes and truss engineering will call for changes to be made. Yes, there are other trusses like the gambrel or cruck trusses to choose from, and one can certainly dive deep into all of the post and beam options, but we have chosen to stick with the primary types.

Our custom timber truss styles provide massive visual appeal, with many options in beam sizing and placement. Structural or non-structural trusses can be used for both stick-built or full timber frame homes. If you’re looking to talk to Arrow Timber about getting a custom timber package built, use the contact form above.

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Timber Frame Truss Styles and Their Uses
Timber Framing
Timber Frame Truss Styles and Their Uses
Articles on Timber Framing
Here are the top 9 Truss Styles: 1. Simple Truss 2. Cable Truss 3. Scissor Truss 4. Mono Truss 5. Box Truss 6. Queen Truss 7. King Truss 8. Arched Truss 9. Hammer Beam Truss
Bert Sarkkinen
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