Curved wood beam

[Struct1206]

Does anyone have any experience with designing a laterally curved wood beam? I have a client who wants a 35' long beam with a 22' radius that will be supported on the ends and at the center. I am trying to figure out the best way to construct the beam, whether it be built up from dimensional lumber or if it could be built up from some type of engineered product. It's going to be outdoors and therefore exposed to the weather so I have to take that into consideration as well. Any input would be appreciated. Thanks.

 

[COEngineeer]

what kind of loading will it take? It is going to be expensive and it will probably be glue lam that is made to curve vertically. You are introducing torsion thats why I want to know if the loading.

Never, but never question engineer's judgement

 

[BAretired]

No experience with that, but I think I would start out by talking to my friendly neighborhood glulam fabricator.

BA

 

[msquared48]

Just use a steel tube section and wrap it with wood veneer.

Tell the Architect that the tube section is a recycled a wood beam that was made to look like steel for use by another architect. He won't know the difference.

Mike McCann
MMC Engineering

 

[BAretired]

mike,

You need another beer.

BA

 

[Struct1206]

The loading will be pretty minimal, it's the main beam for a outdoor pergola. I would say it won't see anything more than 250 pounds per foot at the most. I think I might try to push the architect towards using something other than wood, seems like that might be the best way to go.

 

[BAretired]

mwhite1206,

Who said anything about an outdoor pergola? What the hell is a pergola, anyway? You are guessing. You need another beer. If you and mike want to get together for a beer, let me know...I'll be there!

BA

 

[COEngineeer]

They sell curved glulam that can be outside.
Check this out

http://www.rigidply.com/glulam/curvedbeams.htm

but like i said, it is usually vertical curve but for small load like that, I am sure you can make it work.

Never, but never question engineer's judgement

 

[msquared48]

Give the glulam manufacturer a six pack. He'll make it real curved.

Mike McCann
MMC Engineering

 

[civilperson]

No problem, the torsion is limited to the 70 degree arc between supports and the center suport will get loads from both arcs. Rectangular wood sections have good torsional properties, (as do rectangular steel HSS). Vertical laminations bent around a jig or form and then glued will hold the desired radius. A good polyurethane finish would be recommended as well as waterproof glue or epoxy.

 

[hokie66]

Before you give this client a laminated beam for a pergola, you need to find out what he wants it to look like, and for how long. If he wants a clear finish on the beam like you would see in a church roof, the finish won't last long in the sunshine, no matter what newfangled coating is used. Maintenance will be required often, say every 12 months if lucky. If he is going to use an opaque finish, then he might as well use a steel tube.

 

[COEngineeer]

Or use curved steel beam, put web blocking every so many feet, put top and bottom plate very so many feet so you dont have to curve the plates, then buy thin plywood and wrap the beam.

Never, but never question engineer's judgement

 

[kslee1000]

BA:

Pergola: "A framework that supports climbing plants".
A tree branch can do that.

 

[msquared48]

BAretired:

The Pergolas I have are paintings. What were you thinking that a Pergola is? Maybe I shouldn't ask.

Mike McCann
MMC Engineering

 

[BAretired]

I thought it was a long narrow boat which was rowed by pergoliers in the waters of Venice.

BA

 

[kslee1000]

arbor,bower,mandrel,mandril,pergola,spindle
All new to me.

 

[BAretired]

kslee,

Is this any better for you?

Definitions of pergola on the Web in German:

* Die Pergola (italienisch zum lateinisch pergula = Vor- beziehungsweise Anbau) ist ein raumbildender Säulen- oder Pfeilergang, der ursprünglich im Übergangsbereich zwischen Haus und Terrasse mehr zur Zierde denn als Sicht- oder Windschutz dient. ...
de.wikipedia.org/wiki/Pergola

* Pergola ist ein Ort mit 6819 Einwohnern (Stand am 31. März 2006) in der Provinz Pesaro und Urbino, Region Marken in Italien. ...
de.wikipedia.org/wiki/Pergola_(Marken)

* Architektur: raumbildender Säulen- oder Pfeilergang, Überdachung, Vordach
de.wiktionary.org/wiki/Pergola

BA

 

[kslee1000]

BA:

I quite bear 20 years ago, I feel I need one
Is that real in Germany? Where are those little dots? Oh, yea, you need special key board.

 

[BAretired]

kslee,

Maybe you prefer Dutch:

* Pergola is het tweede album van de Nederlandse band Johan. Na het debuutalbum "Johan" hadden fans vijf jaar moeten wachten op een nieuw album van ...
nl.wikipedia.org/wiki/Pergola_(album)

* Een pergola is een constructie van latten op hoge palen in de tuin waar langs allerlei planten kunnen groeien. Meestal is deze gemaakt van hout of metaal. Pergola's worden vaak tegen de gevel van een een huis of ander gebouw geplaatst. ...
nl.wikipedia.org/wiki/Pergola_(tuin)

* Pergola is een gemeente in de Italiaanse provincie Pesaro-Urbino (regio Marken) en telt 6864 inwoners (31-12-2004). De oppervlakte bedraagt 113,5 km², de bevolkingsdichtheid is 60 inwoners per km². ...
nl.wikipedia.org/wiki/Pergola_(Pesaro-Urbino)

* Groeiwijze van de wingerd. Komt voor in Rias Baixas, Spanje en op Bali, Indonesië.

http://www.wijnwinkel.nl/content/wijnwoordenboek.aspx

* It), een doorgang overdekt met een latwerk waar klimplanten tegenaan groeien.

http://www.stedentipsvoortrips.nl/glossarium/termenpbb.htm

BA

 

[kslee1000]

I need BEER, not BEAR

Mike: Had BA party with you this morning?