Help with wood beam slice location

[D189379]

I'm building a deck and am making a 2-ply 2x10 beam that will be 22' long and supported on 3 posts (approx 9' between posts) So the beam will cantilever 2' on each end with 2- 9' spans between the posts. Still with me? So the issue is that I need to build the beam out of 2-10' and 2-12' pieces of 2X10. I'm tring to figure out the best place to splice the beam pieces. I was thinking of a 12' and 10' piece on one side, then cutting the 10' piece into 2-5' pieces and putting those one each end of the beam, with the other full 12' piece in between them. Then screwing everything together and using splice plates. Sound good?

 

[Tempest]

The splices should always be above your posts, but with the material you have, I don't see how you can do that. Unless you somehow join the spliced end (mending plates maybe), your beam will only be as strong as one board.

 

[D189379]

Hmmm, I guess that makes more sense. I'll just put the 10' and 12' end to end, the flip the other 12' and 10' piece and screw it all together. I think I overcomplicated it.

 

[D189379]

I know steel beams aren't spliced over colums, they're usually done at 1/3 points of the span(or 1/4, can't remember).

 

[Tempest]

They have strong connections. Bolted plates usually.

 

[FADEC]

I recommend asking a structural engineer, or at very least a structural manual showing proper technique. The reason I'm saying that is that I'm selling my home and the inspector wrote up a similar 2x12 splice joint, as being not allowed (the house was built this way). Had to have a structual engineer come in and state it was okay. MAJOR pain in the [censored].

 

[Gary Allan]

Just make two 22' spans with the 10' and 12' inverted on one or the other span. Offset to allow both center splices to be at the same spot for center column. Place outboard columns at points where both spans are common. Splice in 2 - 2' pieces beyond load bearing points outboard of outboard columns. They should be under no stress.

 

[Pablo]

What kind of wood?

 

[IndyIan]

 Originally Posted By: D189379

Hmmm, I guess that makes more sense. I'll just put the 10' and 12' end to end, the flip the other 12' and 10' piece and screw it all together. I think I overcomplicated it.

Your using pressure treated? I think you'd be fine but if you ever think its going to be inspected, I'd add a 3rd layer atleast. The building code in Ontario for decks is pretty over built and depending on the load area you might have to go with a 4 ply 2x10 beam... I think the one span for my 8' wide front porch is 10' and there is 4 2x8's for it. I think the hangers would fail before the beam would and maybe that is the codes design criteria... Your library should have a copy of the building code. P.S. Where is Canada City? Google maps came up with Ottawa when I put it in...

 

[tomcat27]

personally I think your plan is fine (10,12 then 12,10) although I would join them with carriage bolts with washers and not rely on screws alone. if I can get ahold of my contractor buddy, I will update.... oh, and to keep the BITOG theme... pour oil all over it!

 

[TooManyWheels]

How about getting an engineered beam, 3 1/2" x 22'? Only problem would be getting it delivered, but the lumbar yard might do it. Or, use a 22' metal plate in the wood sandwich.

 

[Gary Allan]

He's really got 10' spans for the columns (allegedly 9' apart). The 2' on either end should not require such high integrity as the center splice.

 

[Tempest]

 Originally Posted By: TooManyWheels

How about getting an engineered beam, 3 1/2" x 22'? Only problem would be getting it delivered, but the lumbar yard might do it. Or, use a 22' metal plate in the wood sandwich.

I don't think he has a crane.

 

[TooManyWheels]

 Originally Posted By: Tempest

I don't think he has a crane.

I replaced my garage door header with 2 2x12x16' engineered beams. Shoehorned them into the place of the old ones with the help of two friends. Longer length or not, I would think putting deck beams (or plate) into place in the open would be do-able.

 

[D189379]

 Originally Posted By: IndyIan

 Originally Posted By: D189379

Hmmm, I guess that makes more sense. I'll just put the 10' and 12' end to end, the flip the other 12' and 10' piece and screw it all together. I think I overcomplicated it.

Your using pressure treated? I think you'd be fine but if you ever think its going to be inspected, I'd add a 3rd layer atleast. The building code in Ontario for decks is pretty over built and depending on the load area you might have to go with a 4 ply 2x10 beam... I think the one span for my 8' wide front porch is 10' and there is 4 2x8's for it. I think the hangers would fail before the beam would and maybe that is the codes design criteria... Your library should have a copy of the building code. P.S. Where is Canada City? Google maps came up with Ottawa when I put it in...

Calgary. The building code also calls for me to dig down 7' into the ground and put a 2'x 2' pad footing at the bottom of each post, so I'll think I'll pass on trying to meet any type of code. It's pretty common for homes to have "non-conforming" decks, at least around here. I ended up talking to an engineer friend and he said I'm fine with just flipping the 10' and 12' pieces. I put about 20 screws through the spliced area, as well as added 2 splice nailer plates on each side. Then I poured GC over it.

 

[oilyriser]

Does the place you are buying the wood from have a finger joint cutter? You can glue two pieces end to end this way and they will be as strong as a continuous piece.

 

[IndyIan]

LOL, you don't want to dig 7' holes for your deck... Reminds me of a Mike Holmes episode where he was reinstalling a front step to code, dug down to the level of the footing under the foundation to find undisturbed earth... Anyways it was built to last longer than the house but it probably would cost $10k to do it... Nice front steps! Anyways sounds like your deck is fine unless you have 40 or 50 sumo wrestlers over for a BBQ...

 

[D189379]

 Originally Posted By: oilyriser

Does the place you are buying the wood from have a finger joint cutter? You can glue two pieces end to end this way and they will be as strong as a continuous piece.

It's home Depot, not sure but the beam is already together. Seems strong.

 

[Tempest]

If you used good sized mending plates you should be fine.

 

[D189379]

And just to put your minds at ease, the deck is only 12' deep, and there are 2 of these beams and 2 rows of posts, so one beam carries about 120 sq/ ft of deck, the other does about 60.