Return to the Greenhouses & Garden Structures Forum | Post a Follow-Up

 o
Pergola with curved beam

Posted by bill_g_web z9 CA (My Page) on
Sun, May 7, 06 at 15:04

Has anyone built a pergola with a curved beam? I suppose the way to make the beam is to laminate 5 or 6, 1" boards together, using outdoor glue. (The curve is gentle enough that 1" board might work. If nbot, I'd just have to go thinner.) Maybe once the columns are in, I could use them somehow as the form for gluing up the beam laminations. Any thoughts? Other methods?

Thanks,

Bill


Follow-Up Postings:

 o
RE: Pergola with curved beam

Some other ideas: Cut the curves from an already curvy branch (this will be stronger), cut the curves from a larger piece of wood (say ply). Steam bending.

Steam bending is the traditional way for load bearing beams, but that was before the invention of power tools and cross linking PVA glue.

You won't be able to get a good curve using only the columns (and you'll have trouble with them moving under the force). Better to make a curved former out of ply or MDF and use lots of clamps (like 1 every foot). There will be a lot of force applied for the first few laminates, so you'll need the former to be very strong. A good idea is to cut the shape in thick board then drill 1inch holes every foot to put your clamp in.

I'm surprised that you can bend 1 inch wood, but my US friends tell me that your hardwood is lot less stiff than here, so it might work.


 o
RE: Pergola with curved beam

how much of a curve?


 o
RE: Pergola with curved beam

I'm guessing a radius of about 6 feet - nathanhurst is right, 3/4" is too thick to make that turn, unless it's green and steamed. I guess what I'm looking at is 1/4" boards, built up to a beam of about 3 1/2", unless you've got another suggestion.

(I might try wandering in the woods to see if I find something natural to work, but that's a long shot. I've tried steam bending wood for a snoeshoe project and I don't really see that working out for this application.)

Thanks,

Bill


 o
RE: Pergola with curved beam

Steambending would work well for this project, assuming a radius of 6, (I have no idea what a pergola is) I can definitely see 1/2" ash making that kind of a bend id steamed, they do it in boat building all the time, Ash is the wood of choice for mking a fair curve like the one you want/need. I also like the idea of cutting it out of a large curved branch or trunk, I suggest Titebond III, I've read Rave revieds in a few wood working publications including Tautons Fine woodworking.


 o
RE: Pergola with curved beam

Does anyone know of places you can -buy- curved beams?


 o
RE: Pergola with curved beam

Would you consider using Trex for at least this portion of the project? Trex isn't great for really heavy loads but should be able to handle the load of a Pergola. I do know that it bends easily as we have done that on a playground project I worked on. I would also like to build a curved front pergola and Trex seems to be the easiest solution so long as I don't want a white pergola (which, of course, I do).


 o
RE: Pergola with curved beam

Can you bend trex with a heat gun?


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Greenhouses & Garden Structures Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here