The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: hackberry jake on October 27, 2011, 03:51:07 PM

Title: covered bridge construction?
Post by: hackberry jake on October 27, 2011, 03:51:07 PM
My dad bought 100 acres of wooded land a couple years ago, and just recently bought a smaller dozer. He's wanting to use the dozer to improve the roads, build a pond, and level out a spot for a cabin. He wants a covered bridge across the pond for four-wheeler traffic and fishing. I've been pondering how to construct it. I thought about a floating bridge, but I'm starting to lean towards building either rock and mortor pillars, or concrete pillars every 8' or so. How would you build them so they wouldn't settle much? I would then run 3 2x8s or so across the spans for support, and 1x for the boards on top. His land consists mainly of oaks and hickorys. He has a good amount of cedar, but I hate using cedar structurally. Would hickory or red oak last if used in the roof section?  I imagine white oak will be the wood used for the platform. Any opinions?
Title: Re: covered bridge construction?
Post by: paul case on October 27, 2011, 07:46:07 PM
Are you talking about for purlins or rafters and a metal roof? If so, then hickory or oak will last you a lifetime, if you die when you should.

PC
Title: Re: covered bridge construction?
Post by: hackberry jake on October 27, 2011, 08:56:27 PM
Yes, rafters and purlins for the metal roof. I believe he got the idea of the bridge from the woodchuck commercial. "DanG woodchucks... quit chuckin my wood!" That guy has a bridge across a river or pond of some kind. Sure would look neat, not so sure its worth the labor and timber though.
Title: Re: covered bridge construction?
Post by: thecfarm on October 28, 2011, 06:58:24 AM
Don't forget to leave a gap between the floor boards to let the dirt fall through. Good over hand on all sides,the ends too.
Title: Re: covered bridge construction?
Post by: bandmiller2 on October 28, 2011, 08:05:28 AM
I would study the design of a simple truss then upsize it to the size you need. Frank C.
Title: Re: covered bridge construction?
Post by: Dave_ on October 28, 2011, 12:00:59 PM
A timber framed structure might be cool.  You might want to go over to the timber frame forum and bring it up there.
Title: Re: covered bridge construction?
Post by: hackberry jake on October 28, 2011, 08:37:30 PM
I could possibly get away with longer spans if I made timber trusses. The top of the trusses could hold up the roof rafters somehow. Could I get a moderator to move this topic over to the Timberframe and log construction section? Purdy please.
Title: Re: covered bridge construction?
Post by: Rooster on November 01, 2011, 10:48:03 PM
What is the total span of the pond?  I have built a covered bridge that spanned 51ft with a Multiple King-post truss wall system.  Town lattice trusses are easy to build because there isn't any mortice and tenon joints, just overlapping 3x10s with 2in, trunnels.

http://www.past-inc.org/historic-bridges/image-towntruss.html


Sounds like a fun project!


Rooster
Title: Re: covered bridge construction?
Post by: hackberry jake on November 04, 2011, 02:46:58 PM
I'm not too sure about the span of the pond yet as we haven't began construction yet. I need to know how often to build the supports. I plan on building them in the dry before we seal up the pond.
Title: Re: covered bridge construction?
Post by: losttheplot on November 04, 2011, 05:57:50 PM
I was going to build one of these once.

http://mathemati.ca/1040a.html

If your span is 24' or less.
Title: Re: covered bridge construction?
Post by: jdtuttle on November 05, 2011, 10:40:58 AM
If you haven't dug the pond yet put a small island in the middle & have either two shorter bridges or use the island for center support. A friend of mine did his this way & it looks great.
Jim