Construction question (deck)

[Richard]

We've got a guy who's building a deck and adding a small area to the house.

Attached is a picture (sorry for the BLUE, seems I had camera on "indoor lighting")

Anyways...

I've tried to draw in the item of my question.

Today, they added another post (the skeleton in yellow). In addition to this post and per the blueprints, they added "two 2x12 dropped girder" and this section is the left/right yellow (pardon the great draw job I did!)

This girder is two 2x12's that on the house side, go into a slot that they cut into the block wall so it's got great support. On the post side, it's currently nailed to the post and they'll probably add the hanger later on. At least, that's how they did the other joists.

Here's the crux of my question...

They took a SINGLE 2x12x18 (this span is right at 18') and in essence, took another 2x12x15 and a 2x12x3 and married the 15' and the 3' boards onto the single 18' board to give them "two" 18 footers.

I don't know but my logic says that this is NOT two 18 footers since there is a break in one of them...I'm ONLY going to have the full strength of a single 18 footer and maybe some additional strength by the added parts but I will NOT have the strength of TWO 18 footers.

Is my logic correct or am I being too ****?

I'm ready to call the builder and have him yank those down but don't want to put my foot in my mouth as I'm so wanton to do.

Any thoughts would be appreciated.

BTW, I'm looking at the blueprints and they call for "2 2x12 dropped girder"

??

 

[blueriver]

I didn't see the pic's ... is there plywood sandwiched between the 2x12's?

 

[Richard]

I should have added that, if you look closely at the picture, just to the left of the skeleton post, I put a vertical line. This vertical line is about where the two different sections of boards meet (the 15 and 3 footers)

 

[Richard]

Ya....stupid me forgot the picture

I looked and do NOT see any plywood sandwiched between.

I'll go look again right now

 

[Richard]

Well, this just got interesting. (realize it's been dark when I get home)

I was wrong....

There are THREE boards and not two as dictated by the blueprints. However, it gets more interesting....NONE of the three boards is on its own, 18' long.

For lack of better description, let's just say that the first board has a seam at 3', the THIRD board (both outside boards) has a seam on the OTHER side of the run at maybe 3' (actually I think it was a bit more) and the MIDDLE board has a seam right about the middle.

So, NONE of the boards are a true single board. Each section of the three boards is made up of two boards to give the net 18' length.

hmm.... gets more & more intersting

 

[blueriver]

Here is the way I look at this, if the beam is supported only on the ends they need to have plywood. If they are fastened to the exsisting structure and nailed to every stud thus transferring the load ... should be okay

Keep in mind, I am not a builder or an engineer!!!

 

[Richard]

It got even more intersting....

going outside got me even more curious so I not only took my camera out BUT my tape measure.

EACH of the three "beams" is made up of two boards, not a single one of them is a continuous board. The plans call for two 2x12's and this is made up of three 2x10's and not ONE of the three 2x10's is 18' long. Virtually each one is made up of two boards to sum to the right length.

I'm thinking I like this less and less....

I'm hoping someone here can calm me down and explain why this "is" ok (as contrasted to "might" be ok)!!

 

[powergod]

You can do that as long as the breaks are off set, but be warned it can weaken it. I have something similiar on my deck but at each break i put a kicker under it just for piece of mind, usually you see this type of beam used vertically not horizontally. I figure a few kicker beams is cheaper than an entire new deck or a law suit

 

[Richard]

By 'kicker' beam, may I presume you mean some kind of post under it to support the seams?

It DOES look as though they put some nails in at least one of the boards, to help attach it to the joists above.

There is NO call for any kind of support post under these..in fact, the posts would be in the way of the walkway.

 

[2manyrocks]

Typically, builders prefer to install built up beams because shorter sections of wood are easier to handle than longer ones. I have no clue whether a triple 2x10 beam has the strength of a doubled 2x12. The number of nails used, their spacing, and the size of the nails can affect the strength of the built up beam. I think you need to continue asking your question until you get a satisfactory answer and before you pay for this work.

Kind of strange that they'd be going back and adding another post with the built up beam after everything else is up.

While you are asking questions, did the builder install flashing between the upper deck surface and the side of the house? (circled area). Looks like water splashing off the upper deck surface and water running down the side of the house could create some issues, especially with wood siding/timber exterior if this is not flashed well.