what is the maximum length of timber beam for practical/transportation purposes?

[delagina]

I have a 50' long platform. Can I have 2 - 25' timber beam?

In steel we usually have 38' as maximum per transportation.

 

[jayrod12]

Depends on the type of lumber, but in my experience standard lumber maxes out at around 18-20 foot lengths. Shipping is never a problem.

If this is a follow-up to the last platform question, piles may be longer, but the platform framing itself you'll want to keep the lengths down around that 18-20 feet to ensure availability.

A call to the local lumber yard would confirm that.

 

[btrueblood]

Solid timber or engineered (e.g. glu-lam)?

 

[mike20793]

Same as a steel beam for engineered lumber. Sawn lumber will have limits on the lengths available. It's unlikely dimensional lumber will be available in 25 ft lengths, but LVLs, LSLs, PSLs, or glulams can all be manufactured to length. Watch out for manufacturer requirements for re-sawing.

 

[delagina]

I have a 50' long platform and I'll use 2ply-2x8 beam Southern Pine. Since I cannot have 25' long beam,
should I have 4 timber piles/posts and splice the beam at the posts location?
Or can I have 3 timber piles at 25' distance and splice the beam somewhere in the middle?

I read it's not ok to splice the beam in the middle and should be at the top of the post

 

[mike20793]

I would not splice the beam at all. I'd use simple spans to size it and Simpson connectors.

 

[jayrod12]

Do not splice at midspan.

Do what Mike says. but if your platform is similar to the photo you posted (or is a replacement for that platform) then 2 ply 2x8 seems light.

Post your intended framing plan and we can comment with more accuracy. What did you choose for a design load in the end?

 

[delagina]

just to be clear when you say simple span, you meant 4 timber posts? and beams will be flushed at each other at the top of posts but not connected to each other?

I'm looking at deck beam span length (table R507.6). it seems 16' or 18' seems too long for 40psf. Should I be looking at 5 or more timber piles and 3-ply beam?
I probably will use 100 psf live load.

 

[jayrod12]

I think you should be using solid treated timbers for the beams, i.e. a 6x8 instead of a 4 ply 2x8 (Just an example, did not run a single calculation). I also think that you should space them based on the pile capacity, but not further than the 18 feet as you will have a hard time getting timber beams to work on spans further than that.

100 psf is a good design load for something as you showed in your other post. I would also get equipment weights for anything that will be supported by the platform, the point loads may exceed the effect of the udl in certain areas.

 

[delagina]

is this the connection I should be using for beam to column simple span?
I'm confused because the beams are connected by plate and bolts.

 

[Brad805]

That will be difficult when you consider the piles may not end up exactly where you want or perfectly plumb. Any reason you could not use galvanized spikes? I bet that original structure was all put together with spikes, and other than decay, it appeared to be a functional design. Simpson SDS screws might be an option too. Considering the remote aspect of the project I would keep it simple wherever possible.

 

[delagina]

i'm trying to figure out the best connection actually. that's the connection i saw in timber design manual. can you elaborate more on galvanized spikes detail.

i saw this detail wood pile to beam detail from FEMA but doesnt this look difficult field cutting top of pile?

http://www.anthonyforest.com/assets/pdf/fema-wood-pile-to-beam-connections.pdf

 

[jayrod12]

He's just talking about extremely large nails that are galvanized. They can be up to 8 or 10" long and almost the thickness of your finger. I don't mine the detail you posted, since you're planning on using conventional timber, you should be able to cut the beams to suit the saddle (That's what I call the steel assembly in your pic).

Will your wood piles be square or round. I don't have much experience with them but I've seen them round in most cases.

 

[delagina]

@jayarod, I'm still waiting for geotech report for skin friction of timber piles. I think I finally figure out the connection.

I should be connecting the transverse beam to top of pier.
Then connect the longitudinal beam to the transverse beam. I saw that detail in pedestrian bridges.

 

[Lomarandil]

Back to the original question, contractors seem to do alright getting 30' and 40' timber crane mats around.

 

[boo1]

Round piles are easier to work with and cheap.
Why attach to the top of the pile? Consider heavy 2.5 CCA timbers on the side of the pile, bolted with heavy galv. carriage bolts.

 

[delagina]

We maybe going with steel platform with timber pile. I told the PM if corrosion is the only concern, even with wood platform we are still going to have steel connections. We don't need to deal with wood connections and standard that we don't have. I still learn a lot from your help. Thanks,

 

[Brad805]

This structure reminds me a lot of the portable bridge decks we use here. They drive loaded forestry trucks over those, and the only bolts used are between the bridge girders and the 8x8 beams. I attached a link below.

https://www.for.gov.bc.ca/hth/engin.../bridge-drawings-2012/STD-EC-020-05_Rev-1.pdf

There is nothing wrong with the steel connections you have found in the wood manual, but once you talk to the heavy timber guys that actually build this I would expect them to ask why they need these. These require more planning since we (engineers) usually ask for shop drawings, and then they have to wait for them to be galvanized. Then if something goes wrong on site and they have to field modify, then you have a new problem to deal with. If your loads require such a detail, fine, but if not, I would try to avoid the complexity.

Thru bolts in the field are not all that easy unless you allow a greater tolerance for the bolt holes. We usually get asked to sub lag screws on both sides, since very few timber framers have the drill press below that will allow one to consistently drill thru a large timber accurately on site.

http://www.timberwolftools.com/tools/mafell/MAF-BST.html

Did you talk to any framers as another posted in the other discussion? That will save you a ton of time with all of this. If it were glulams, our supplier will engineer all of the connections and they have specialty designers on staff that are great at dreaming up connection details.

 

[Ron]

The maximum length for shipping purposes, over the road, will depend on your state's requirements. You can generally ship up to about 50 feet without a special permit and escort; however, longer than that will likely require a special permit. (Most trailers now are between about 45 feet and 53 feet long)