Timber Truss Design Styles
& How to Find Your Unique Truss
Finding your unique truss style is both rewarding and fun. It will have a very large impact on how your timber space feels. As you move through the process of getting your timbered living space, you will continually gain more insight into your style preferences. 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.
Because building practicality always plays a hand in which truss design is chosen, it's important for you to know that your original ideas will probably change as you gather more information and talk with your friends about what you intend to do. Talking with your friends will also be a factor in which design you end up choosing. This is because our acquaintances often know us better than we know ourselves. With both building practicality and the influence of our close acquaintances affecting the end design you'll choose, it is best to be flexible with the design you have in mind the whole while. The following timber truss style descriptions have been combined with tips on how to modify both the strength and the elegance factor so you can make your timber truss unique!
- Multi-Web Truss
- Parallel Chord Scissor Truss
- Lane Truss
- Glue-Lam Modern Truss
- Gambrel Truss
- Compression Ring Truss
The simple truss examples shown here really is a lesson in simple elegance. If you are the type of person who is unpretentious and straightforward, this may capture your personality well.
The no frills solution this truss presents is ideal in many situations, especially as a "Second Act." This means that another timber element is the main visual focus, but the Simple Truss is placed so that it presents a secondary visual surprise. For example, it could be used as a secondary feature behind a more ornate Hammer Beam front truss. As you can see, the size of the simple truss is limited to the load bearing capacity of its members, since it doesn't have webs; this means your typical truss span will max out around 30'.
The king truss is probably the most common used style of exposed timber trusses... There is an explanation for this- Timeless Geometric Beauty! A cross cultural gem that can really be adapted to fit any style. Arched bottom timbers and curved webs are commonly used to dial up the elegance factor.
A common mistake you'll want to avoid if you choose the king truss style is positioning the angle of the webs 90 degrees, or perpendicular, to the sloped/top beams. This is a mistake repeated often, probably because it seems easy and natural to align the webs at right angles to the top chords, but it really kills the balance; the center of the truss will appear pinched or cramped, especially so with the lower pitched trusses. I believe it is better to align the webs by eye to achieve the best balance- the same principal applies when your are deciding how much arch a truss should have or how much to raise the bottom member if it fits better- 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.
What is special about a queen truss? The most significant aspect is the kind of style it lends itself to.
Think of this truss as Craftsman or European style. 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. One particular client planned to display an old large canoe, resting in the rectangular "storage space," created by the spread out queen posts.
Here is one of my favorites, the scissor truss! You have so much flexibility and can do so much to balance and capture the exact feeling you want for your timbered space. Before I list all of the available options for you, I should mention that this truss style doesn't work well if you need to tie knee braces from your truss, down to your posts, such as a free standing outdoor pavilion. I have only found two designs to stylishly achieve lateral bracing in conjunction with scissor trusses. I just wanted to make you aware of the constraints before diving into all of the many scissor options that are available to you.
- Offset centerline
- Iron rods and integrated arches
- Variable slope
- Multiple webs
- Double Top load or DBL B.C.
If you have a space where two opposite walls vary in height, you may be well served with a scissor truss- the peak, or center line is off set and aligns where the two roof slopes converge- a perfect way to elegantly bridge two different wall heights.
Wrought iron rods (horizontal tie rods to be precise) often improve the elegance of a scissor truss. A very elegant scissor truss we had the opportunity to do combined arches and a horizontal tie rod. A modified scissor truss with an arch borrows elements from the Queen truss- the bottom chords begin in the same way as a normal scissor truss but then terminate at a vertical post placed at approximately 1/4 to 1/3 of the span, a tie rod connects the bottom of these vertical posts and an arched berm connects the posts together near the top. It's a very unique truss which feels like an elegant throwback to castle days.
Another nice twist you can get with a scissor truss is to implement a ½ lap with the bottom members, This allows the bottom chords to each continue to the top member creating an "X" that really resembles scissors. This also increases the strength of the truss because the pieces are interwoven. Bigger spans will allow you to experiment with different web angles and web orientation along with the actual steepness of the bottom members. All of these factors allow you to adjust the intimacy of your timbered space.
The Scissor Truss really blends well with all styles- Western Rustic, Contemporary and Old European. It could perhaps even fit the Cottage Bungalow style if the roof pitch was low enough to keep the space intimate.
The mono truss can be easily adjusted to be a scissored mono truss if desired. I see space intimacy as the biggest reason to slope the bottom chord of a mono truss. If you have a need for a mono truss, I'll wager that you have a unique style.
A vaulted ceiling typically terminates at the beginning of an upper level or overlooking a great room. Most of the mono truss applications I have seen have been "Secondary Act." That is to say that the mono truss is normally used as a stylish solution for a portion of your living area which is a hub of your living space. In certain cases, certain style tendencies combined with a unique front door access,(a front door that is alway approached from the side, for example) can create perfect conditions to use a mono truss for your entry solution.
Hammer Beam Truss
This is often referred to as the crown jewel of the Timber Frame industry, and with good reason. It is very aesthetically pleasing. It has a well established and rich history. One can even create a lofty living space and yet retain a feeling of closeness, warmth and security.
Hammer Beam Truss
Typical uses are in great rooms, churches, entries, and attached pavilions. When you choose a Hammer Beam truss, you will be locking in the "old" or rustic factor of your living space. This truss is more along the lines of Old European style. With heavier beams, angular beam details and a lower roof pitch this design begins to fit more into the Western Lodge class.
There are two advantages regarding the Hammer Beam truss: Short pieces, and Many pieces. First, short pieces mean you will not have to pay a premium price as short members are less costly. Second, having many pieces means you can influence the overall feel of your living space fairly easily. To add elegance, braces can be curved, and beam sizes can be trimmed. Conversely, adding beam girth and straight braces creates a stronger feel. Due to the fact you have so many braces, your choices can have a big impact.
Personally, I like to use the Hammer Beam Truss for bigger applications that are designed for specialty use. By specialty use, I mean a place such as a church, a gathering hall, park pavillion or even an indoor pool space. Any space designed to handle a group of people on special occasions or events is made more cozy with the Hammer Beam Truss Style
To explain why the Hammer Beam Truss fits so well in bigger applications, I've developed a theory. It seems that the Hammer Beam Truss has a special advantage that makes it work especially well in areas of big volume because of its special ability to make bigger spaces feel more intimate. Somehow I am drawn to the principle that a big space or space with a lot of volume needs to be filled with a lot of people. If you are thinking of using the Hammer Beam Truss in your home, you may want to be mindful of this principle. It seems uncomfortable to set up your own personal relaxation space in an area that is oversized. You'll want to think about proportions and how you want your space to feel.
The Hammer Beam truss is a special truss. After many years in the Heavy Timber Frame building and design industry, it has become clear that a significant percentage of people that become attracted to Timber Living are first attracted via pictures of Hammer Beam trusses. They may ultimately choose a different truss style as they move through the design process, but the fact remains that Hammer Beam trusses have one of the highest "Wow" factors of all truss styles.
This gem goes back even further than the Hammer Beam truss. It provides a simple solution if there ever was one- Basically the cruck truss is formed by leaning two timbers against each other at the roof peak and connecting them well. Often the cruck truss, or cruck frame, will use naturally curving timbers for the main bearing members to allow for more head room or useable space. These curving members also add to the beauty of the structure. You can also use a cross between a cruck and Hammer Beam truss to build your Timber Structure. This involves a long knee brace running from the peak, down to the vertical exterior posts. Many of today's steel industrial buildings simply eliminate the knee brace running from the peak to the exterior post/column and use the post/rafter connection to pick up strength.
As far as style goes, the true cruck truss is definitely limited. If you are choosing the Cruck Truss, you must already have a very steep roof, which means that your starting point stylewise will be Mountain Lodge or old European. The best looking Cruck I have seen to date was built in Australia-This barn was formed with wavy irregular timbers, sawn flat on only 2 or 3 sides, leaving one side of the tree untouched. Of course "best looking" comes down to personal preferences and taste. But, I feel like the rounded, irregular element of the Ausralian Cruck really was consistent with the ancient history and architecture of the cruck system.
To imagine the setting in which a Multi-Web Truss would be used, think of old industrial buildings or big open spaces; The polar opposite of the setting for the simple truss. The distance the truss can span is limited to the load capacity of the top members, so, by adding multiple webs you can increase your truss span. The extendability is the reason that multi-web truss styles are usually found in big commercial applications. Keep in mind, there have been many instances in which adding extra webs really puts a nice touch to the overall look of the truss and structure, even though the truss was already strong enough.
You will see many examples of metal tension rods incorportated in a multi-web truss, usually right in the middle, in place of the main vertical post. The vertical tension rod is an effective way to give the truss a modern touch while also increasing the resistance to tension. Rods lend a very distinct look; the rods can be black, stainless steel, or even rusted. I personally think that the Multi-Web Truss and Tension Rod combo is quite attractive.
Parallel Chord Scissor Truss
This truss is a close cousin to the multi-web truss. Its form mandates many webs to achieve strong stability. The most common reason for the use of this truss is for the unique style it has and the message it gives. The style it portrays is along the lines of a Hardworking Lodge style; it gives a powerful message of "This is a place where things get done."
Parallel Chord Scissor Truss
This truss is not elegant by any means! This truss fits best in a situation in which there is a high ceiling to work with and a desire to achieve a more rugged and industrious feeling.
Like the Parallel Chord Scissor Truss, the Lane truss is yet another relative to the Multi-Web Truss. This truss also radiates a message of "industrious" and "rugged." The lane truss is usually used to build a "hipped" roof, meaning that the roof slopes down on all four sides. A hipped roof also has a continuous gutter around the whole building. The form of the lane truss, with the noticeable lack of a peak, allows the possibility to place a truss closer to the corners than if you had normal truss with a peak.
I would choose the Lane Truss primarily for cases which structurally require this unique form, the only exception being a situation where a normal vaulted ceiling would seem too high or make the living space feel tall and narrow.
Glue-Lam Modern Truss
As the name implies, the choice of materials and the sleek lines of the uninterrupted curve, evoke pictures of exotic blue glass, contemporary furnishings, and a unique use of unusual building material.
Recommendations simply don't work as well with this contemporary style of truss, largely because the heart and soul of "Contemporary" style means architectural surprises-Here is an instance where I could visualize aluminum or stainless steel connection plates. Contemporary style will never have a description that can fit into a box!
Glue-Lam Modern Truss
Typically this style has smaller sized members with more space between the trusses themselves, often coordinating with modern visual surprises such as using old corrugated metal in place of wallpaper as wall covering, hanging art from the ceiling. This type of truss will definitely achieve a contemporary look while still retaining the feeling of home.
The Gambrel Truss would fit perfectly for a barn, an art studio, or any place which naturally has a strong connection with nature. The reason this style fits so well with nature settings is mainly because of the almost universal shape we know as barns. Some Victorian homes I once saw are an example of where this truss style was incorporated well. These homes incorporated a special roof style, known as a Mansard roof, which is basically a barn roof on all four sides. Generally, your choice to build using a Gambrel Truss will show your close affiliation to nature, farming, and self reliance.
When designing the truss itself, I would recommend a straight forward design. Arches should be left out and needless timbers avoided. The same minimalist strategy applies to the timber sizing also; nothing extremely massive, just functional like the barn itself.
Compression Ring Truss
Whether the Compression ring is a truss or a roof system is up for debate since it works as both! It acts as a truss in that the downward loading force is resisted by members locked together in tension. It also functions as a roof system by itself. The roof of a gazebo is an easy example of where the Compression Ring works well as a a standalone for the roof.
Variations of this truss configuration are a popular way to construct outdoor living pavilions and barbeque shelters. The main benefit with this truss is the unique open feel from the inside-no webs, no posts, just an open space framed with timbers! There are many ways to get creative with this truss, though. If you desired an Italian feel you could curve the whole roof up to make it like more of a dome. A curve in the opposite direction may lead lend an Asian feel to the structure. A dual pitched roof (meaning that the front of the roof has a different slope than the sides) could give you more of a Polynesian look and feel.
Compression Ring Truss
The Compression Ring Truss is really flexible to any timber style, although with a structure of larger scale it would lose some style flexibility. A bigger building would require larger timbers, which would lock the style to Heavy Rustic. Wherever you end up placing this truss, I recommend it in a location where you desire an open and energetic feel.
There you have a good representation of the majority of truss types which have proven the test of time. The goal of this article is to make you aware of two things!
1. First, to make you aware of different truss styles and to help you develop an idea of how you might blend or personalize your style to your liking.
2. How your choice of truss style will be influenced by: your personal tastes, width, depth, and height of your timbered space, and your location, natural surroundings, views, prevailing winds, site access and so on.
Of course you have more choices than just what style of truss you get for your timber package! You'll still need to decide post size, floor beams, knee braces and way more, but the choices you make with the roof or the ceiling have the most impact on how your timber space will feel, whether it's your get-away cabin or a community hall you sponsor.
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