Construction question (deck) any builders or architects here?

[Coytee]

We're building a small room onto the house and adding a porch. Sorry for the BLUE picture, I had my camra on "indoors" when I took it.

The picture of the house...has a "skeleton" where today, they put the last post in. In addition to this post, they put a beam in, represented by the horizontal yellow line.

Here's where it gets interesting to me....

The plans call for "(2) 2x12" dropped girder" as in two of them going from the block wall to the post. Today, they cut into the house and installed this dropped girder.

Instead of being made of two 2x12x18's, it's made up of THREE 2x10's.... it gets more interesting... not ONE of them is 18' long. Each of them is comprised of two pieces to make the total length. There is NO plywood sandwiched between them.

I am not hung up on the 2x10's as I presume having three of them is going to be similar to having two 2x12's...what gets me is NONE of them are 18' in length, they are ALL made up of 2 pieces.

Logic tells me if I had at least ONE 18' board, then I'd have at least the strength of a single board, bolstered by the addition of the 4 boards nailed onto the side. As it is, I don't think I even have the strength of ONE 18' board.

Am I right? wrong?

As it is... I've put my cell phone down about 34 times, preparing to call the builder and have a pretty stern talk with him about how quickly that mess is going to come out.

I've put my feet into my mouth before so I figure I'd ask this time. No sense in proving what an idiot I can be if I have a chance to cover it up a bit!!

Thoughts?

[Coytee]

Board 1

[Coytee]

2

[Coytee]

And third board.

As you can see, virtually all of these boards have a seam where they've taken two boards and summed them to be 18'.

One outside board has the seam about three feet from the end. The other outside board has the seam "near" the middle and the inside board, has the seam near the opposite end (of the opposing outside board).

That make sense? I guess I could have simply said, they staggered the seams. []

[TNRabbit]

Not a problem; it's done all the time on extended spans. It would, of course be BETTER with sandwiched ply material, but not essential.

[Guest " "]

The beams are not a problem....it looks like they are nailing them in...I prefer screws. Where the beams butt I use metal stock which is predrilled with screw holes on at least one side of the joined beams.

I personally would use a poured footer foundation rather than use poles in holes. If your going to have a room on the bottom and a deck on top...poles in holes anit going to cut it.

You also need to think about 2nd and 3rd year leaks into the lower room from the deck floor. Ideally, you would want to put in a pitched standard roof first with just enough pitch to lead the water away from the house and then put the deck on top of that level.

I did one of these 4 years ago and the poured foundation is still perfectly level all around. You won't get that with poles in holes.

[colterphoto1]

I'm not a civil engineer, but there are tables where one can look up the load bearing capacity of various widths and numbers of common SPF (Spruce, Pine, or Fir) boards. I would imagine that this is what they did when using triple 2x10 in lieu of double 2x12. Sometimes the larger lumber is cupped and these beams appear to be made of good flat specimens. The boards should be joined by a good quantity of 16 penny nails, some might use lag bolts but this is not common as you'd have to drill pilot holes, weakening the wood. Wood screws would not have the necessary shear strength and are generally avoided.

Another issue is economics. Longer board, especially in wider widths, must be made from bigger trees, therefore more costly. Building up your beam from 4-5 boards that are 2x10x12 feet in length probably cost substantially less than a beam made up of two 2x12x18 feet.

The method of joinery seems fine. The joints should be staggered and though you may question having a joint 3' from an end, this is much preferable from having all joints in, say the middle 6' of the beam. No gusseting material of OSB or plywood is needed, these are sometimes used in window or door 'headers' to make up the difference of the 3.5" wall thickness being made up of two members of 1.5" thickness and the OSB/plywood in the middle of the sandwich.

[Coytee]

I personally would use a poured footer foundation rather than use poles in holes

2 comments/questions

1. Regarding poles in holes... they DID dig a hole about 18/24 inches diamater and pour concrete for a support under these posts. is that what you mean? It's rained and even right now, the concrete would be exposed except for the rain which has washed some dirt inside there and covered up the view of the concrete.

2. If the plans call for two 2x12's and they installed three 2x10's, might I presume the three 2x10's will be strong enough... secondarily, since the plans CALLED for two 2x12's... you're suggesting that these patched boards will suffice... but since it's not what the plans called for, would you let it ride or would you have them yank them out and install three 2x10's

[gaspr]

You might want to ask your local building official to have a look...unless of course you are doing all this without a permit...[:#]

[Coytee]

unless of course you are doing all this without a permit

We've got a permit. I also realize the inspector might not catch everything that I'm curious about... I'm actually creating a list of little things so when the inspector does show up, I can ask specific questions on specific items.

[colterphoto1]

Be careful not to inspect your way into a 'Stop order'.

I'd advise talking to the architect and have him bring his (or better yet a third party) engineer-type for a look see and some load calculations. Think of this as an independant third party, like an auditor. He's just after the truth and making things right, has no financial stake in the contracts, and is paid directly by you the owner.

I'm concerned about the method of attachment for the upper posts that will support the eventual roof as well as the need for a post dead center under the main deck due to the beam not being sufficient to span the 18'. I did not know about the roof business until we spoke last night.

DO NOT do this while your carpenter crew is on site unless you want a brouhaha and someone stomping off. Are you on good terms with the builder? Can you be open and honest with him about your concerns without causing a contractural nightmare?

[chrisinvermont]

As others have stated making the beams out of "staggered" members is fine and is pretty much industry standard. As for the (2) 2x12's vs. the (3) 2x10's I would make sure the architect or designer knows about the field change. I would start there before going to the building inspector. There may have been a design reason for the 2x12's, yes some of us do think things down to such a detail!

As for the structural aspect it has been nearly 20 years from architecture school and my structures classes but the (3) 2x10's isn't a problem. If I recall correctly (I have a structural engineer review my projects now) when you are designing for a load you figure out the load on the various members. From this load you can determine the bearing required for the beam. With wood I recall that your bearing properties are based upon the cross section of the wood. You will need a certain area in order to hold the load. (2) 2x12's will have a cross section of 33.75 inches (11.25" X 3"). Going to (3) 2x10's will have a cross section of 41.625 inches (9.25"x 4.5"). This would indicate that the 2x10 are actually much stronger than what was spec'd originally.

Good luck and verify with the architect that the substitution is acceptable. I would also try and get a credit back from the builder for using 2x10 instead of 2x12s. There is a really good chance he did it because the material was cheaper and it was easier (cheaper) to install.

Chris

[Coytee]

Thanks all for the input...

Between my flare up and now, I scrutinized the blueprints in a bit more detail...

Seems there is a little square that was overlooked by some dufas (hmm...I wonder who that would be [:$])

There is going to be a 6x6 support right under this beam. I had thought this beam was held on two points but it's going to be held at those two points plus its midpoint. Having been on the deck prior to the beam being installed, I would have been happy with NO beam (certainly ignorant of it not being there too).

They put it in, I was happy with two support points...now with me seeing there are actually three points of support, I don't think there is much to concern about.

As for difference in materials from 2 2x12's verses 3 2x10's... I might let that one go by the wayside.... I won't however, let it go by the wayside, where we have since decided on NOT putting some stairs up to this porch. Plans called for it, the bid called for it and now we've nixed it.

I've already confirmed with the builder that the plans (and bid) called for the steps that we are now not going to build, so I want him to prepare a document for me that shows how much will be deducted. (I'm well aware that he'll deduct less for not doing it, then he would have added on FOR doing it...amazing how that works)

[]

[gaspr]

I've already confirmed with the builder that the plans (and bid) called for the steps that we are now not going to build, so I want him to prepare a document for me that shows how much will be deducted. (I'm well aware that he'll deduct less for not doing it, then he would have added on FOR doing it...amazing how that works)

Good chance that before your builder is all done, you will find some "extras" for him to do which could, in effect, cancel any credit due you...funny how that works.[8-|]

Good luck with your project.

[colterphoto1]

"They put it in, I was happy with two support points...now with me
seeing there are actually three points of support, I don't think there
is much to concern about."

other than it makes the space under the deck nearly entirely useless, you mean?

Somewhere in your contract with the builder it probably states that all changes will be agreed upon in writing. That means figure out the deduction and sign a change order as the changes are being made. Keep up to date on this, don't wait till the end to argue it out.

[CIGARBUM]

Always hold back 10% retainage.

[Pete H]

I'm sorry I didn't find your post before this or I would have gotten involved. I've been building for 20 years and I'm a finatic about decks, and though there are times where you can do substituitions for various beams and joists, they all have to be based on load calculations and common sense and I hope your builder gave you info. to support the change, let me know if this whole thing is done or if you're still dealing with it and I'll try and provide fair information.

Pete

[Coytee]

Hi Pete & thanks for the thoughts.

Seems the inspector has already been out and given the general "ok" other than, he wants them to add one more support beam that was otherwise not in the plans.

No one really wants that next post but it will be close to the house. The inspector dude evidently, felt there wasn't enough lip/support where they channeled out the blocks for the beam to rest on.

Here's picture of current situation however, the last part of the railing is finally installed.

[colterphoto1]

Looking GOOD Richard!

M

[Coytee]

Thank you. I certainly don't get any of the credit though. My wife actually designed it (she designed the entire place if you want to know the truth). She however, had to take it past an architect to get it 'approved' for lack of better word. He's the one that took her drawings on a napkin and made them work. My job is to pay for it. [:S]

The guys doing the building... well, one of them, is a craftsman who seems to really care about what he does and along with being a very laid back kinda guy, seems eager to go the extra mile to insure a smile on your face when he leaves.

The other guy, who fortunately, isn't one doing much of the woodwork, is the general contractor and kind of a hard head.

We'll probably have a couple more projects after this is done and now that I know what I know, I'll contact Jason directly and hire him without going through his 'partner'. (I say that because he told me the other day they are not "partners" and he does his own projects all the time so he's not tied to the hip with Larry)

They have signed on to do a job in north Georgia and are in chats about building another log home in Nashville area. Seems the lady in Nashville wants to come see my place to see what they've done here. I told them that was fine by me.