# Proper Way to Laminate Deck Beams



## GBrackins (Apr 26, 2012)

there is only one way I know of and be compliant when doing this, hire a professional engineer to determine how to laminate the plies. prescriptive building codes require that plies terminate on some type of support whether a column, hanger or beam.

you have to have the correct number and size of fasteners when attempting to make up a laminated beam.

I'd go with your second option of having all plies supported over a column. you need a connection to prevent lateral movement between the column and beam


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## MTN REMODEL LLC (Sep 11, 2010)

GBrackins said:


> there is only one way I know of and be compliant when doing this, hire a professional engineer to determine how to laminate the plies. prescriptive building codes require that plies terminate on some type of support whether a column, hanger or beam.
> 
> you have to have the correct number and size of fasteners when attempting to make up a laminated beam.
> 
> I'd go with your second option of having all plies supported over a column. you need a connection to prevent lateral movement between the column and beam


Agree with Brack above.... but you must have some long spans. (Ideally you would do both, stagger and land on post...but you knew that by your question.)

Plus we don't know if you're building a 1 foot high deck or that lam is supporting the second story in a high wind shear earthquake environment.

Landing on the post might be as simple as some simpson strapping on both sides, or maybe a simpson post cap in 1/4 bolt thru.

Safe is get an eng/stamp if application necessitates.... you have at least two different forces to evaluate. Plus the eng may spec certain laminating techniques like glueing, nailing/clinching,bolting etc.

Good luck


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## ModernDayDarwin (May 18, 2013)

MTN REMODEL LLC said:


> Agree with Brack above.... but you must have some long spans. (Ideally you would do both, stagger and land on post...but you knew that by your question.)
> 
> Plus we don't know if you're building a 1 foot high deck or that lam is supporting the second story in a high wind shear earthquake environment.
> 
> ...


I'm building a 30' deck on the summit of Mt. Washington (2nd place for highest supported wind speed). Do you think my triple 2x4's will be enough? :whistling2:

Nothing near that exciting. It's a 20' wide deck and I have a large supply of 10' boards.


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## MTN REMODEL LLC (Sep 11, 2010)

ModernDayDarwin said:


> I'm building a 30' deck on the summit of Mt. Washington (2nd place for highest supported wind speed). Do you think my triple 2x4's will be enough? :whistling2:
> 
> Nothing near that exciting. It's a 20' wide deck and I have a large supply of 10' boards.


Oh... didn't understand.... you just need a board stretcher... I think Harbor Freight has them on sale.:thumbup:

Best

Peter


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## md2lgyk (Jan 6, 2009)

I'm just an experienced DIYer, but I don't think spanning 20 feet with triple 2x4s is going to work. You need an engineer.


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## ModernDayDarwin (May 18, 2013)

md2lgyk said:


> I'm just an experienced DIYer, but I don't think spanning 20 feet with triple 2x4s is going to work. You need an engineer.


It was a joke.


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## GBrackins (Apr 26, 2012)

ModernDayDarwin said:


> I'm building a 30' deck on the summit of Mt. Washington (2nd place for highest supported wind speed). Do you think my triple 2x4's will be enough? :whistling2:


and here I thought it was 30' on a triple 2x4 ..... :laughing:


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## hand drive (Apr 21, 2012)

the first pic is the correct way. stagger the seams so that they do not land all at the same spot. I start the first row from one direction always breaking center of column or really close to center and then switch the direction for the next row until the beam is complete. staggering the seams locks the beam in, nail the separate boards to one another really good also to help form the beam.


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## MTN REMODEL LLC (Sep 11, 2010)

Just as a rough rule of thumb that an engineer did tell me one time,

when laminating dimensional, by staggered nailing and clinching over long nails, and glueing with PL or Liq nails, you get about 80%+ of the streangth characteristics as if that was one solid (non-laminated) piece.

That does not exactly address this circumstance of staggered lengths, but only to the extent that laminating it up well can't hurt.

Best...

Peter


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## Willie T (Jan 29, 2009)

BTW, in case no one has told you....... Dat's too far for 2x4's.




(Sorry........... Couldn't resist.)


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## MTN REMODEL LLC (Sep 11, 2010)

Willie T said:


> BTW, in case no one has told you....... Dat's too far for 2x4's.
> 
> 
> 
> ...


 
How long do you want those 4x2's.....?

Oh, a long time... I'm building me a deck.:yes:


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## jagans (Oct 21, 2012)

I am pretty sure that most local yokel codes all require you to end all plies of a girder over support. Why? because they will not assume that you used the correct amount of fasteners and the correct type of adhesive to construct your girder. You need a structural glue to bond your members together properly.

As far a the statement about 2 x 4's Im not sure what the OP is trying to do. If that was supposed to be a joke, he ought to be on stage. There's one leaving in ten minutes.


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## MTN REMODEL LLC (Sep 11, 2010)

jagans said:


> I am pretty sure that most local yokel codes all require you to end all plies of a girder over support. Why? because they will not assume that you used the correct amount of fasteners and the correct type of adhesive to construct your girder. You need a structural glue to bond your members together properly.
> 
> As far a the statement about 2 x 4's Im not sure what the OP is trying to do.* If that was supposed to be a joke, he ought to be on stage. There's one leaving in ten minutes*.


New one for me.... I'm going remember that.

Actually, I think *you* are dead right, code wise I think an inspector is going to want those landed on a post.... as to strapping or post caps tieing together...I don't know. 

(Although, I don't know if his question even involved code and he was just asking which we thought was a better trade-off given that he was going to use existing lumber. 

But, it really is unanserable without knowing all the specs/loads. For all we know, he could be using 12"x stock on an 11' span which is triple laminated and so overbuilt that I would then vote to stagger lams and not land on a post to give better stability at the post w/o strapping etc.?

However, I'm pretty sure the OP is not really using 2x4 stock and he was being facetious... although he never did mention his absolute spans nor size of dimensional lumber.

Best

Peter


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## GBrackins (Apr 26, 2012)

MTN REMODEL LLC said:


> although he never did mention his absolute spans nor size of dimensional lumber.
> r


and he did say ......



ModernDayDarwin said:


> It's a 20' wide deck and I have a large supply of 10' boards.


I was always taught a board was 1x and lumber was 2x .... 

but then his question was


ModernDayDarwin said:


> For a span that is larger than you can purchase lumber for, what is the _*proper*_ way to laminate dimensional lumber together to create the beam?


the proper way is to end each ply over a column, beam or hanger, or have an engineer determine it. At least in my area.


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## MTN REMODEL LLC (Sep 11, 2010)

GBrackins said:


> and he did say ......
> 
> 
> 
> ...


Unequivocally Yuup :thumbsup::thumbsup::thumbsup:


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