Missed Engineering!!

Cache

In a nutshell:

2-story house. Main floor is 16" trusses 19.2"oc. Second floor is TJIs 16"oc. North wall in kitchen lies a few feet north of (and parallel with) basement bearing wall, perpendicular to floor trusses. Floor trusses were supposed to be engineered for the load. I was in a hurry during framing and didn't check the specs when trusses were delivered. That group of trusses were visibly more "beefed up" than the rest of the floor, so I ASS-umed that they were properly engineered.

4-way inspection and the inspector says, "I need the other documentation showing that these trusses have been properly engineered." Of course, that is when I notice that they weren't properly engineered. Informed by truss company that the only fix is reduced spacing. Not a possibility as HVAC, Plumb, and Electric are done.

Options:

1. Either LVL or Steel beam across bedroom ceiling in basement, directly under the bearing kitchen wall. HO says "No Go!" on the idea of a beam across the basement ceiling. I don't mind as that one woulda needed footers to be cut and poured.
2. Reinforce TJIs to be able to span the required 24', effectively converting the bearing kitchen wall into a non-bearing partition. Engineer at joist manufacturer says getting an extra 4' span will be difficult without adding more joists. Again, no go, due to HVAC and plumbing.
3. Steel beam across kitchen ceiling (probs something like 5"x5"x1/2" square tube). Same concept as #2 in removing load from kitchen wall to convert to non-bearing. Cost = $800 + labor assuming no unexpected engineering problems. New engineering docs required.
4. 16" LVL across kitchen ceiling. Beam pockets added to exterior kitchen wall and opposing staircase bearing wall. 11 7/8" TJIs cut in half across kitchen ceiling with a 3.5" slot running perpendicular to joists. Double 16" LVL inserted into slot. 11 7/8" face hangers installed. Resulting 4" reveal of LVL beam below kitchen ceiling. Cost = $250 + labor. Also, inspector not requiring eng. docs as this is basically normal framing practice , albeit an out-of-order retrofit.

We went with #4 and I didn't add labor as I shoulda caught this before hand. HO alright with the 4" beam reveal as long as I build a nice coffered ceiling in kitchen to hide the beam.

As a relatively new builder. This was the most difficult field mod/ retrofit that I've had yet. Would any of you seasoned vets have fixed the problem differently?

joasis

Lots of variables there....who did the plans, and why were the trusses not to spec? I would guess if the trusses were speced, then someone has liability.

Now to the fix, looks like you did what any of us would have done. #4 was the obvious choice, and probably can be "hidden" as a decorative touch.

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Cache

Yeah, everyone trying to blame it on the other guy. In the mean time, I just need to get the 4-way inspection done and get on with things. Took a day to get it fixed after a couple days arguing with people about who should pay for it and another couple days while they tried to recommend ways to work around it.

KentWhitten

Well....as the GC you are ultimately responsible, but I've never heard of a truss company designing trusses without them asking the proper people what the loads are going to be designed for....unless there's a curveball thrown.

They just can't say "oh well, your problem" they've got to have some type of responsibility.

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If you correct your mind, the rest of your life will fall into place ~Lao Tzu

Custom Cabinetry - Portland, Cape Elizabeth, Scarborough, Kennebunkport, Yarmouth, Falmouth, Cumberland, Ogunquit, Maine

Salmon Falls Cabinetry

Cache

The truss company was a nightmare to work with anyway. This was the first house I've done with floor trusses instead of TJI. They came out and chalked the foundation to make sure the lengths were correct. The foundation was consistently 1/2" shorter than the plans in the north south direction. Not a big deal at all. Basement walls were all straight/plumb and corners were square.

Shop builds the trusses and delivers them. The majority of the floor simply had the trusses running past each other over bearing walls rather than butting. Then we hit a section of 3 trusses that tied into a girder where there was no bearing wall to sit on. Turns out that the shop had matched the trusses to the plans rather than the foundation. Add to that a girder that was as twisted as a propeller blade, the thickness of face hangers and TICO nail heads. Those three trusses were overhanging the foundation by almost an inch.

I do a field mod to fix their mistake rather than returning the offending trusses, and I get on with the framing as we were already behind schedule a bit. They then tell me that the field mod that I usually do isn't the way they want it done, so I will have to remove those trusses and mod them according to their guide or they won't stamp the re-engineering.

Guess who I'm not going to use on the next house?

Joe Carola

Since this was the first house you used floor trusses, why did you modify them without asking the truss company?

What field modification do you usually do when this was the first time you used floor trusses?

That's why you should've asked them before you modified them on your own. Why would you do something like that without asking, especially with floor trusses when you never work with them.

I would never modify a floor truss or roof truss without talking to the manufacturer who made them.

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Joe Carola

KentWhitten

well...field modding is a no no...sorry.

I don't know of any truss company that visits the site and measure existing. They always do it by plan.

I always build to plan myself, that way any problems are the architects, not mine.

Sounds like an absolute cluster ****.

Let me try to describe it the best I can in as short as I can. If you yourself are saying you are a little on the green side, people will take advantage of that. If you are certain of your abilities and show the authority that you should be showing, then most of your problems can be avoidable.

You must know what you are doing and show your conviction. Otherwise be prepared for more.

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If you correct your mind, the rest of your life will fall into place ~Lao Tzu

Custom Cabinetry - Portland, Cape Elizabeth, Scarborough, Kennebunkport, Yarmouth, Falmouth, Cumberland, Ogunquit, Maine

Salmon Falls Cabinetry

Cache

I see minor field mods of trusses done all the time, including field repairs for broken trusses. Especially roof trusses that tend to get broken a lot when they are dropped on site.

You're right though. Points well taken. It was my fault for jumping the gun on that field mod. I shoulda gotten their specs first. I got impatient after a couple days of waiting for them. this was definitely a case of an overconfident youngster.

When I said my usual method for field mods, I was referring to how we usually fix joints on roof trusses. My mod was 6" piece of 1/2" OSB running the full 16" depth of the modified end, glued and nailed every 4"; on both sides of the truss. Theirs was a 12" piece of 1/2" OSB the full 16" depth on one side and nailed every 4", no glue req.

The worst part is that those three trusses are carrying very little load. We're talking about 6' span between girders in a hallway.

Cache

Thanks for the advice. I'm sure you experienced guys see it all the time when a kid (29-yo is still a kid right?) has worked for you for a while and decides he has the ability to strike out on his own.

Looking back on instances like these it seems I might be a product of my environment. Seems that I was "taught" to cut corners on certain things.

Joe Carola

Yes, I'm sure you do, remember one thing since you are new at this, you can NEVER modify a floor truss or roof truss without the truss company telling you what to do, IN WRITING!

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Joe Carola

joasis

What Joe didn't mention was liability....the engineer's seal on the truss system is good only when they are installed according to spec. Any modification transfers all liability to you from them.

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Morning Wood

You've got to check all the loads yourself when a truss company or TJI company does stock plans. Doing an addition now and guys missed a bunch of stuff. Speced out double 11 7/8" LVL to carry shed roof and structural ridge. 22' span on the LVLs. Way off, actually trip 18" LVL. Whenever I work with I joists I make sure and double check everything before I start nailing them in. and then I check again before subfloor goes on. I would have probably gone with the #4 option. although I would have been worried about the fitup of the cut I joists to the LVL beams. I don't envy that little project.

Cache

Yes. I'll keep that in mind from here out. Thanks

Burby

Framerman & others offered you some good & true advice. Additionally though, when you or anyone feild modifies structural load points to keep a job rolling on, always be careful to not overload another point and create a whole new problem.
The problem typically won;t show up today or tomorrow, but in time it sure will with cracking drywall, floors sags, ect.
The new load point should be traced back downwards to ensure proper bearing all the way back to the bottom including proper footing.

Trusses can be a life saver in framing with large spans, but if placed wrong North / South, East / West direction for the design to catch all loads they can also be a night mare. Nice, but still not good, is when a truss manufacturer screws up. Rare, but can happen, their computor software is pretty intelligent. But the one running it is human and they to can have a bad day.
I have field repaired many trusses, but each one has a letter with the plans from an Engineer to verify repair per Engineer's specs. Even if the same type of repair over & over, even if from the same truss Engineer, each one has their letter attached.

Nothing beats experience and each build is an experience lesson for you.
Never beat yourself up for trying, learn from it and move on!!

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SAcarpenter

I don't mean to steal the thread or go off topic but all these situations seem to have the same thing in common; All the responsibility falls on us. On just about every piece of paper we get from architects or engineers it always says we're responsible in the end. The house I am currently working on is a 10,000 sq ft, conventional roof framed house. The second floor framing plan and the roof framing plan were so screwed up I ended up drawing out the way I thougt they should be framed and had to get to them signed off by the idot that drew them wrong in the first place It's like the builder paid them for nothing. It just really chaps my rear that we are expected to just accept such substandard work as "part of the building process" Anyone else feel the same?

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CrpntrFrk

We have had a truss company come to our site! The truss company did not like what was on the plans so they wanted to come to the site and make sure everything would jive. Wish I had pics because usually you don't see two guys in polo shirts with a tape measure on thier hip until the cabinet reps come to the site.

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borat_borat1950

The main problem i have had with truss companies, and not to mention anyone specific (BOISE CASCADE) With BCI's, is they do not think. They go off span charts and do not even look at things like flooring materials, mom's grand piano in the living room, the fact that I want a bonus room is to store my bowlingball collection there, well you get the point.I always design my own package and submit it to them, so that I know there is minimal deflection. My best advice is to always question anything that they send you before you install thier product. They just have a little machine they sit in front of that has taken the thinking ability away from them. Same with architects, most plans I get say not for construction????Then what are they for??? Most say THE BUILDER is responsible for local codes and design loads. I've rambled long enough on this, but bottom line is don't trust anything they give you!!!