Every single spring and summer, each tree grows another layer of wood that is added onto the trunk. In the spring the wood grows quickly and is a lighter color because it is made of large cells. During the summer the wood grows much slower, has smaller cells and is darker in color.
To tell the age of the tree – Count the dark rings!
When a tree is getting plenty of sunshine and rain it will have rings that are broad and evenly spaced.
If a tree has went through a forest fire it may have some scarring on the bark right along one of the rings but every year the tree will add more wood to cover the scar.
Very narrow rings that continue through several seasons can indicate a drought or maybe an insect infestation.
If a tree has rings that seem wider on one side than the other it may suggest that something pushed against the tree as it was growing. The tree will build what is called “reaction wood” to prop up and support the side that is leaning.
Many considerations for the design and fabrication of a pavilion are rooted in how the finished product will look. Behind the scenes we make sure that the design is structurally sound. The form and function areas of design are all the while being considered. This is highlighted in the pavilion roof framing through a form that makes the function a visible design parameter. This is how a timber frame gets its shade, not to mention the overall ‘look’ of the finished product.
Considering a pavilion roof usually starts with the question of roof style. The two most popular styles are gabled and hipped. A gable roof has a peak running parallel with the eaves. Principal rafters (members running from eave to peak) are the main support in this type of roof framing. A hipped roof pavilion has a high point to which each eave runs up to. Hip rafters (members running from each corner to the high point) are the supporting members used in this other style of roof.
Each design has a unique look and the applications are endless. For example, a gable roof can be square or rectangle with varying roof pitches to accommodate different truss styles and site requirements (existing structures, etc.). Gable truss style options are also seemingly endless varying from king post, queen post, hammer beam and so on. A hip-roofed pavilion has a different set of options that are varied as well. The structure can be square or rectangle but the plate (eave) is of the same height at each side. More often than not a boss pin is used to join the hip rafters at the high point. A square structure receives a singular boss pin while a rectangular structure receives two, one at each high point connected by a timber ridge.
Completing the look of a pavilion is done with the roof design. Large timbers with wide spacing can be used to give a bold and heavy look while smaller members can be spaced closer together for a light and airy look. Beam spacing is decided in design adhering to roof loads and a timber’s ability to carry that load. Form and function reside together in harmony and the pavilion roof system becomes the structural focal point of the frame. Once the pavilion roof system is sheathed and finished in the owner’s selected material, it is time to sit down and look up!
A Pattern Language – Towns, Buildings, Construction
By Christopher Alexander, Sara Ishikawa, and Murray Silverstein
Oxford University Press – 1977
This is Volume 2 of the Trilogy; The Timeless Way of Building (Vol. 1) and The Oregon Experiment (Vol. 3)
“You can use this book to design a house for yourself with your family; you can use it to work with your neighbors to improve your town and neighborhood; you can use it to design an office, or a workshop, or a public building. And you can use it to guide you in the actual process of construction.” Christopher point out in this 1100 page book what to consider in space relationship within rooms, the importance of large front porches and using them, to how a neighborhood should be built in order to interact with each other. He draws some of his conclusions from how the ancient European villages and towns were built; how the inhabitants lived amongst the structures which created a community; and how important privacy is and where it should be located in a house. Some ideas will surprise you, but some will cause you to wish for the older ways of living which combined the outdoors with the interior spaces of your dwelling.
Building the Timber Frame House – The Revival of a Forgotten Craft
By Tedd Benson with James Gruber
Fireside Book – 1980
“Timber framing is as old and as full of history as the story of architecture in wood itself. As a building technique, timber framing survived through the centuries on the sound principle that it provided exceedingly durable shelter.” So begins one of the first books on the resurgence of timber framing in the United States. Tedd Benson tells the story of this forgotten craft and how its rediscovery has led to what we witness today in private homes, commercial buildings both large and small, and in outdoor pavilions for farmer’s markets as well as State Parks. This paperback book is recommended for the beginner, the historian, and is considered a staple on any timber framer’s book shelf.