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.

 

[Lasgambler]

Do you have permitted plans for this job? Do you have building inspections in your area? If you have inspections, express your concerns to the inspector, then he will be sure to "catch it". I have been building for about 38 years now and will not use dimensional lumber for built up beams. I'm not an engineer but, a 3 1/8X12X18 Glulam would serve you much better there. Factor in there labor of making a built up beam and they did not save much.

There method of building the beam, with glue and a proper nailing pattern will hold together, although over time I think it will sag. I have seen these things before.

Then on the other hand you are paying the Tab, and they did not follow the plans, Have them change it.

 

[EddieWalker]

I'm with Lasgambler in his advice. Tell the inspector what bothers you and get him to do an extra thorough inspection.

Since you have a plan, I'm assuming it was engineered? If the permit was issued for a plan and it specifies a certain sized piece of lumber then that's what has to be there to pass the inspection. A 2x12 will be 11 inches tall. A 2x10 is 9 inches. With a 18 foot span that supports the floor joists, I wouldn't take any chance with anything besides what was specified in the plan. Liability now falls on the builder if it fails. It doesn't cost him any more to order the correct material and 2x12 come in lengths up to 24 feet pretty standard.

If it was me, I would have set the posts on 16 ft centers so I could buy lumber off the shelf, but with planning, it's not that big a deal to order special lengths. I've never used gluelams for exterior work. I guess you can buy them for this, it's just not something that I've done. For interior work, they are not very expensive, and their strength is far superior to anything else.

I'm unclear on the additional post. Did they do this as an afterthought? Mistakes early on in a job are good signs of trouble down the road. Everyone that I've ever worked for who has had problems with their contractor have all said that they knew early on that there was something wrong, but they stuck with them as long as possible with the hope that it would work out in the end. It didn't. Listen to your inner voice.

Eddie

 

[Richard]

Do you have permitted plans for this job? Do you have building inspections in your area? If you have inspections, express your concerns to the inspector, then he will be sure to "catch it". I have been building for about 38 years now and will not use dimensional lumber for built up beams. I'm not an engineer but, a 3 1/8X12X18 Glulam would serve you much better there. Factor in there labor of making a built up beam and they did not save much.

There method of building the beam, with glue and a proper nailing pattern will hold together, although over time I think it will sag. I have seen these things before.

Then on the other hand you are paying the Tab, and they did not follow the plans, Have them change it.

I'll admit I don't know what you mean by 'permitted' plans. I know you're saying it from a county inspector point of view as opposed to "allowed". I don't think anyone in the county has viewed these plans if THAT is the answer.

We do have a building inspector and I DO plan on having the stuff (house in general) inspected. A bit off topic... I've got a wire in the ground that needs to be put into the wall. The builder we have was going to lay the wire on the gravel at its exit point from under ground, "bend" it back to the wall and at the wall, put a piece of conduit such that it would APPEAR as though it was in conduit when in fact, the conduit was a ruse.

I looked at him and said that was totally unacceptable and he knew about this wire before they did such & such.... now he's admitted that his scheme would not have passed inspection and I think he realizes I'm watching some of these things.

Regarding asking the inspector about this... are you suggesting I should wait for (let's say 8 weeks) until we're at a time for inspection OR, maybe have the inspector come out "now" at my expense and have him do a mini-review during the middle of some of this?

 

[Richard]

I'm unclear on the additional post. Did they do this as an afterthought?

I'm going to answer that with a "no" since they dug and poured the foundations for ALL of them at the same time.

They built the deck in what I would have thought, an unconventional order.

They dug for post foundations, poured the concrete.

Came out later and put MOST of the posts in (skipped 2) and put the outer bands up. They then installed the joists BUT, they installed the joists without hangers. Once the joists were installed, they had a guy go around and install all the hangers.

I presumed they did it this way so they could strike a line and get all the joists at a level height and add the hangers later.

I personally, would have thought to install the hangers first and THEN install the joists.

Be it as it may, that is how they did it. They then came back and installed the last two posts.

This specific post will also be where the stairs will be so I've wondered if that is maybe why they did it that way.

Bottom line...I've got ZERO clue why they put the last 2 posts in after the rest of the stuff was up. I've also got zero clue why they put the joists up and then the joist hangers afterwards.

I looked at the blueprints and they call for 2x8 joists. I personally would have paid MORE out of pocket to have 2x12 joists installed. Maybe 2x8 is good enough...maybe 2x8 is good enough with this mentioned beam under it... I don't care. The outer skirt of the deck is 2x12 and I would have wanted 2x12 joists simply for asthetic reasons.

I've been on the porch and before they put this beam in, it seemed very solid. I've got to think joists of 2x12's might have gotten them around this beam (and maybe not). unfortuantely, I didn't catch this until after it was installed and since it's what the plans call for, I don't think I can be too ugly about the 2x8 joists.

 

[john_bud]

Regarding asking the inspector about this... are you suggesting I should wait for (let's say 8 weeks) until we're at a time for inspection OR, maybe have the inspector come out "now" at my expense and have him do a mini-review during the middle of some of this?

Look at it this way, If you have the inspector out now on your dime, he can catch stuff that is being sluffed off before the entire house is falling down. Given the economy, there are lots of builders wanting work. If this one is a poor performer - fails to follow code - fails to follow plans, get a new one.

If you have to pay 1000 it's worth it. Is this on your bought property? IF so, you NEED to be at every meeting with the sub-contractors when they get paid. OR, the general may pocket the cash and leave you paying twice. I would call each sub and make sure they are all paid up so far.

jb

If the county inspector can't come out - pay for a private inspector / engineer to come out.

 

[2manyrocks]

Some builders prefer to build the frame of the deck with only a few posts and then go back and install the remaining posts because they use the frame as the reference point to measure where the rest of the posts go. They might have poured the pads large enough to give themselves a few inches cushion to make adjustments in the final installed position of the posts.

If they installed the hangars first, they could slip up and have a mismatch in the installed top height of the 2 x 8 joists and the outer 2 x 12 bands.

 

[Jeepnford]

I'm in the process of building a deck and from what I've been told by people who know this sort of thing is any joints in the support beams should be over a post. What I don'r understand is 18 ft. 2x12's are not difficult to come by. Heavy yes,but better than all those joints.

 

[PILOON]

Joist hangers:
Much easier to do them from under as there are LOTS of nails to go in and you get them more snug by installing afterwards.

3 2x10 rather than 2 2x12's. I'd say better in strength but possibly not as bounce resistant.

Splices offset, kinda standard for a built up beam (better with plywood laminate as mentioned)

Post installation, well I've built decks with only the 2 ends and added the others later as it is actually much easier to get the heights exact without shims that way.

If otherwise you are satisfied with quality why not (for peace of mind) just get him to add one more 2x10 onto the now 3 2x10's to give you a massive 6 x 10 (staggared joints naturally).

 

[schmism]

(i skimmed most of the responses)

but this type of spliced beam is common on multi ply girder trusses. (i have an extensive wood truss engineering background)

It all hinges on the nail pattern used to connect the parts together.

Todays statics class is simple beams.

a simple beam supported on each end has a single major force contained within the material. bending moment. at any given location you can split the board in half, at that location calculate the bending moment in the board. if you were able to pass that moment from one side of the splice to the other, the 2 piece board will act the same as a single piece board. (shear force is also a significant force, but only at the ends of the material and therefore when calc'ing splices is generally negligible compared to the bending force)

so the 3 ply beam built of overlapping splices is very doable if the nail spaceing used to connect the various plys is sufficent to cover the bending moment created from the applied load. (liquid nails adhesive will also add to the connection strength)

as for what nail spacing you need? that depends on the load on the beam, and what size nails/bolts/screws are used to transfer the bending moment.

for multi ply beams, through bolts are nice because you can verify there spaceing for inspection (if there is one) and you get a significant increase in attachment value for them due to the double shear condition they are under.

 

[mjncad]

My suggestion is to check the stamped and approved plans and see what the structural engineer called for concerning the beam. Then bring it to the attention of the builder and if he says that his cobbled together beam will work just fine; get him to provide you at his expense a stamped and signed letter from a registered structural engineer stating that this built up beam will work. If the builder refuses, I would get concerned about what else he is cutting corners on.

I had something similar happen with the house we live in now in which the builder didn't get the main support beam's columns to line up with the concrete piers. I told him I wanted a stamped and signed drawing from a structural P.E. (Professional Engineer) illustrating how the problem would be solved or we would cancel the purchase contract. Our house was a spec home when we contracted on it. You may or may not have that kind of leverage with your builder.

If I understand the conduit and wiring matter, it sounds like the builder is using direct burial rated electric cable from the utility company transformer to your main service panel, and where it comes out of the ground it is encased in conduit where it is exposed on your house. If that is the case, builders do that on a regular basis here. But the deciding factor is what your county electrical inspector has to say, and whether your county has amended the NEC for regional reasons or as a measure to generate extra revenue from re-inspection fees.