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keithnellie
Joined: 19 Jan 2005
Posts: 1
Location: River Ridge, La.
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 Posted: Wed Jan 19, 2005 9:56 am Post subject: lamella roof construction |
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| Does anyone have any information or can anyone tell where I can find information on Lamella Roof construction? |
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disconap
Joined: 01 Feb 2006
Posts: 1
Location: Vancouver, BC
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| Posted: Wed Feb 01, 2006 6:34 am Post subject: re: lamella roofs |
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i am a student at Auburn University's Rural Studio. we are currently working on a structure in which we hope to incorporate a lamella roof. we recently found 3 lamella structures at the mississippi fairgraounds in jackson ms. they all span over 100 ft!! we do have research if you are interested.
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timwarner
Joined: 18 May 2006
Posts: 2
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| Posted: Thu May 18, 2006 2:47 pm Post subject: |
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| I've just finished building a 12' x 20' lamella roof. If you're still looking for info let me know. |
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SDR
millennium club
Joined: 02 Oct 2004
Posts: 1845
Location: San Francisco
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| Posted: Mon May 22, 2006 9:16 pm Post subject: |
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Hey, disconap -- good to hear from somebody at the Rural Studio.
How is that Lamella project coming, and what else is happening ?
I grew up near an old amusement park on the East Coast; several of the "rides" were housed under large Lamella domes -- it was years before I knew what they were.
SDR
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"I'm the commander . . . see, I do not need to explain why I say things. That's the interesting thing about being the president. Maybe somebody needs to explain to me why they say something, but I don't feel like I owe anybody an explanation." GWB |
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MikeMadison
Joined: 30 Dec 2007
Posts: 1
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| Posted: Sun Dec 30, 2007 5:55 pm Post subject: lamella roof |
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| There is a book called 'Modern Timber Engineering' by Scofield O'Brien (published by the Southern Pine Association). The 1954 edition, which I have, has a chapter on lamella roof including drawings and all the engineering calcs. |
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SDR
millennium club
Joined: 02 Oct 2004
Posts: 1845
Location: San Francisco
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| Posted: Sun Dec 30, 2007 6:30 pm Post subject: |
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Mmm. I'm thinking the day has passed for these interesting constructions. Or maybe not: wouldn't a lamella dome require a great many different-sized sticks, an ideal project for a computer, to generate a parts schedule and cut list ?
SDR |
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Lamianted Timber
Joined: 24 Feb 2009
Posts: 1
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| Posted: Tue Feb 24, 2009 4:19 pm Post subject: |
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Lamella fell out of favor by the 1960s due to the many failures. It failed under unbalanced roof loadings whether from snow or wind loads. Many lamella framed roofs collapsed.
It also became more economical to use structural glued laminated timber vs. wood lamella, so that contributed to its demise.
Both wood and steel were used for lamella construction. The Brown County Arena in Green Bay, WI and the Astro Dome in Texas are steel lamella roofs.
Many older text books on wood construction have chapters or at least mentions of lamella.
www.aitc-glulam.org is a great place to learn about structural glued laminated timber.
Andreas |
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nanrehvasconez
Joined: 25 Feb 2008
Posts: 329
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| Posted: Tue Mar 10, 2009 10:11 am Post subject: |
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Building with Glue-Laminated Beams
Kevin Hayes
Glued-laminated timber constitutes an ever-increasing percentage of the framing materials used in residential construction. In 2002, 65 percent of the approximately 338 million board-feet of glulam found its way into North American homes.
Much of this growth is attributed to the fact that glulam beams are available from building material dealers and distributors in stock sizes (typical widths: 3 1/8, 3 1/2, 5 1/8 and 6 3/4 inches). Like all engineered wood products, glulam beams are resource-efficient with highly predictable structural performance. As headers, floor beams and columns, the materials are easy to specify, even easier to work with, and the timeless aesthetics of wood remain unchallenged by other building materials.
Glulam is an engineered stress-rated product created by bonding together individual pieces of lumber having a nominal thickness of 2 inches or less. Individual pieces of lumber are end-joined together to create long lengths referred to as laminations. These laminations are then face-bonded together to create the finished product. On a pound-for-pound basis, conventional glulam can achieve allowable strengths equivalent to steel. Glulam is also among the most versatile of the engineered wood products. It can be shaped into forms ranging from straight beams to complex curved members. Typical residential applications include garage door headers, floor girders, ridge beams and purlins, cantilever beam systems and columns.
Garage Openings
APA EWS-trademarked (Engineered Wood System) glulam beams are supplied with either zero camber or a very flat factory built-in camber, which makes it easy to connect glulam with other wood frame components. Figures 1 through 5 illustrate some of the many simple connection details that can be used with glulam residential garage door headers.
Installation Recommendations – Notching and Drilling
Since glulam timbers are highly engineered components manufactured from specially selected and positioned lumber laminations, an improperly cut notch or a hole drilled in the wrong place can seriously affect the load carrying capacity of the member. Field notching, cutting or drilling of a glulam beam, particularly on the tension side of the member, should be avoided. Field conditions may require making a cut, notch or hole that was not originally anticipated. In some instances, these can be made in areas of the glulam, which are not highly stressed and will thus have minimal effect on the structural capacity of the member.
APA Sturd-I-Frame
One of the most challenging design areas in a home is the narrow wall adjacent to the garage door opening. This short wall section must withstand the same lateral forces that bear on other, larger wall and roof sections of the home. The APA Sturd-I-Frame system gives builders and homeowners a design solution that allows for the narrow walls while providing the necessary strength and stiffness. The connections in the frame allow the Sturd-I-Frame to act as a moment-resisting “portal frame” that resists lateral loads from winds or earthquakes. Glulam beams are readily available in the long lengths that are needed to extend the header over the adjacent walls. The vertical wall segment is wood structural-panel sheathing that overlaps the glulam header and is attached with nails in a specified grid pattern. At the base of the wall, a hold-down connector attaches the wall segment to the foundation (see Figure 6). These two moment-resisting connections, combined with the bending capacity of the vertical segment and glulam header, provide the lateral resistance normally facilitated by shear walls or braced wall sections of a substantially greater width.
Floor Beams
Homeowners appreciate the natural beauty of wood and the warmth it brings to interior spaces. They also enjoy the consistent, long-lasting performance of wood. Unlike large solid sawn or built-up timber beams, glulam, which is manufactured from kiln-dried lumber, will exhibit minimal shrinkage and warping, which ensures a level floor surface. In addition, floors have minimal nail popping and fewer squeaks. Framers find that glulam floor beams are easier to work with than comparable steel beams. Plus, it's easy to connect other wood floor-framing components to glulam because the wood-to-wood connections can be made with standard carpentry tools and fasteners. Nailers are not needed as they are with steel beams, and nail-on joist hangers can easily be accommodated. Since the framing crew can install glulam floor beams, it's not necessary to schedule a second trade crew for steel work.
Glulam beams can span long distances using lighter-weight members with minimal need for intermediate supports, opening the design possibilities in a host of applications. Everyone, from homeowner to homebuilder to home designer, can appreciate the expanded design flexibility of wood.
Hybrid Beams Offer New Design Options
In response to market demands for increased structural performance, APA EWS worked with its member manufacturers to develop a new high-strength “hybrid” glulam beam. This beam uses laminated veneer lumber (LVL) as the outermost top and bottom laminations. The beam has a balanced layup, eliminating the concern about losing structural value if the beam is installed upside down. The hybrid glulam is rated at 30F - 2.1E* as compared to the traditional 24F - 1.8E glulam. Since these high-strength hybrid beams are often used to support wood I-joist floor framing, they are typically supplied in I-joist-compatible (IJC) sizes. This means the depths match the typical residential I-joist depths (9 1/2, 11 7/8, 14 and 16 inches) and the widths match conventional 2-by-4- and 2-by-6-inch wall framing. Hybrid glulam beams are only available in a framing or industrial appearance classification for use where appearance is not of primary concern.
Glulam floor beams can be installed within the floor joist cavity if a concealed application is desired. Many stocking distributors inventory IJC glulam for use with I-joist framing systems but most standard-depth stock beams can easily be used in a concealed floor application with minimal furring. They can also be partially concealed in the floor joist cavity or left completely exposed below the floor framing, adding increased aesthetic value to the room below. Below, the illustrations illustrate a variety of simple floor-framing details incorporating glulam beams.
APA publishes a wide variety of load design charts, substitution tables and connection details for glulam beams and columns, most of which are available online at www.glulambeams.org. For technical guidance on design and connections call APA's help desk at (253) 620-7400.
* 30F - 2.1E is a structural classification, which refers to a beam with an allowable bending stress of 3000 psi and a modulus of elasticity of 2.1x106 psi. An E denotes mechanically graded lumber whereas a V denotes visually graded lumber.
Editor's Note: Special thanks to Kevin Hayes of APA – The Engineered Wood Association for contributing this article. For more information, visit www.apawood.org. |
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SDR
millennium club
Joined: 02 Oct 2004
Posts: 1845
Location: San Francisco
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| Posted: Tue Mar 10, 2009 10:39 am Post subject: |
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That's dandy. Does it address lamella vault or dome construction ?
SDR |
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nanrehvasconez
Joined: 25 Feb 2008
Posts: 329
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| Posted: Tue Mar 10, 2009 2:16 pm Post subject: |
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Modern dome roofs (barrel shape) and cupulas are framed with custom curved, custom fabricated gluelam beam girders as per architect-structural engineer specs.
Lamella construction is labor intensive and is not commonly used unless the carpenters union lends the money to develop this type of building (If you are near San Francisco you could visit the Northern California Carpenters Union hedquarters, it has a Vaulted roof made with Douglas Fir 2 x 4's nailed one piece at the time). |
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djswan
millennium club
Joined: 17 Aug 2007
Posts: 1119
Location: Montana, USA
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| Posted: Thu Mar 12, 2009 7:04 am Post subject: Re: lamella roof construction |
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| keithnellie wrote: | | Does anyone have any information or can anyone tell where I can find information on Lamella Roof construction? |
This forum is looking like a good start.
My dome shops are made from 1x4's nailed together piece at a time too. I would perfer tree branches for the next one, less work. A beaver lodge is a dome.
Farmer Joe with a bunch of 1x4s and nails arching a string line built the shops.
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SDR
millennium club
Joined: 02 Oct 2004
Posts: 1845
Location: San Francisco
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| Posted: Thu Mar 12, 2009 11:33 am Post subject: |
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Can we see a photo. D ? In my new guise as semi-retired cabinetmaker (or "carpenter," to the locals) I never know what I'll be called on to produce next. . .
SDR |
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djswan
millennium club
Joined: 17 Aug 2007
Posts: 1119
Location: Montana, USA
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| Posted: Thu Mar 12, 2009 6:27 pm Post subject: |
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That is cool.  I never even thought about getting a picture of the structure of the shops until this thread. You're sitting there thinking about how you would do it different, and it's pretty much the same. Draw a big arch, bend and nail together.
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djswan
millennium club
Joined: 17 Aug 2007
Posts: 1119
Location: Montana, USA
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| Posted: Mon Mar 16, 2009 2:31 pm Post subject: |
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It's those half circle structures in the background of this shot. I'll see if I can get the camera working to take a close up of the "Farmer Joe" architecture.
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djswan
millennium club
Joined: 17 Aug 2007
Posts: 1119
Location: Montana, USA
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