Stem Wall Out of Plumb 1

[Greatone76]

I'm working as an owner's rep on a project. I didn't design this project. After forms were removed from the foundation wall I noted a significant bow out in the foundation wall. This a typical foundation stem wall. It sits on a 12" thick footing and is 56" tall from the footing to the underside of the slab that goes over the wall. I measures across the building and got an extra inch and an eighth of width from design on the building. Using ACI 117-06 I used 3.2.2 Foundations supporting masonry Horizontal deviation of the as-cast edge shall be the lesser of ±2% of the foundation’s width or ±1/2 in. (13 mm). I asked for the contractor and CM to investigate based on it not appearing to meet that spec requirement. After further investigation it was seen that both side of the building foundation are at max .6 inches out of place, but also the wall is out of plumb by 1" from top to bottom in several areas. The out of plumb and location of the wall waves in an out along the length. I have section of wall that are both leaning out and leaning in significantly. Really crappy supporting of the Symons forms. The contractor and CM submitted a sketch to the designer. Where they want to form the slab that extends over the wall back to be in the correct location. So form the last 12" of height as much as 1" in 12" out of plumb. I am being told that the designer of the project has approved this. Am I wrong to be bothered by this wall having such poor craftsmanship and being accepted? This building is a simple 1 story 8" block masonry wall building, so it shouldn't have any unrealistic loads. But it does have significant loads from the weight of the masonry. I have also been using ACI 117-06 Section 4 to state that the 1" out of plumb far exceeds the 0.3% allowable. Am I right to use that reference? I can't find anything that applies in the Section 3 Foundation Section. Help me out. I feel industry standard tolerances apply and feel they should be met, but what do you do when an engineer signs off on something out of spec? Any good specific arguments about this situation that would help my point?

 

[KootK]

You are right to use that reference and right to be bothered by the poor craftsmanship. I do, however, believe that it is the designer's prerogative to accept the work if they can justify that it doesn't materially impact their design. More than that really. I think that it's the designer's responsibility to work with contractors to find a "do nothing" solution whenever possible. It's good for business, good for projects, and good for conserving humanity's resources.

I wish you were on my field team. Knowledgable + give a damn = pretty rare.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[manstrom]

What Kook said

Put yourself in the engineer's shoes. Does it matter?

Would you want to be the engineer that demands that the wall be removed at the loss of thousands of dollars, or would you want to be the flexible engineer that understands that it is not a big deal.

If it works, it works. No need to waste time and money.

If the owner wants it ripped out, they can have it ripped out. But, it doesn't sound like a big issue.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[KootK]

The owner's rep perspective is an interesting one. There is an entire wing of my company that is devoted to project management. They serve as owner's reps essentially. From time to time, they'll bring issues to me for review on jobs where another firm is the EOR. Something will either be out of tolerance or field repaired. It's always some version of this:

PROJECT MANAGER: "The owner has paid for a particular level of quality. Now that XXX is out of tolerance or XXX has been repaired, they're getting less than what they paid for. Therefore they should be compensated somehow, right?".

KOOTK: "Technically, yes. In most cases, a repaired / out of tolerance component will not be as 'good' as the same component would have been if it were constructed per spec and required no repair. However, that does not mean that the repaired/tolerated defect is not 'good enough'. Good enough meaning that it is reasonable and can be expected to last for the anticipated service life of the building (50 yr or whatever). If you go and harass your contractor for financial compensation and/or unnecessary remediation every time that something needs to be repaired or allowed to violate specifications, you're going to find that your costs will increase substantially on your future projects. Word will get around that you're unreasonable to work with and your projects will get priced accordingly. A better strategy is to let the contractor know that you expect better workmanship, will be keeping an eye on things going forward, but are willing to let this deviation slide because you acknowledge that one has to pick one's battles. That way, as the owner, you are getting something of value. You're getting some good will that you may be able to trade against later on in the project life cycle. Even when it's not built into the contract model (DB/IPD), all projects are collaborative. It pays to be a team player."

As an owner's rep, I'd be interested to know what you think of this Greatone76. I've always imagined that contracts should contain a clause that says something to the tune of "the contractor shall be allowed to fix stuff without being caned to death so long as the design team agrees with the fix". I've yet to find that particular clause anywhere however.

The one glaring exception to all this is that we sometimes enforce corrective action as a means of training our contractors. On a multi story concrete project, I'll often have the rebar reviewed very carefully on the lower floors so that the contractor understand my expectations for quality control from the get go. Even this practice is questionable as contractors are generally grown ups too and should be treated as such. I guess that I reconcile myself with this practice by only being punitive with things that are relatively inexpensive to fix. $100's versus $1,000's.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[TehMightyEngineer]

Another side that was somewhat mentioned but worth mentioning again is the level of "good enough". Everyone eventually sees something in an existing structure or component that went horribly wrong over time. From this most people can get a feel for the cutoff point where components will not perform acceptably and, conversely, how much some things can be screwed up and still perform. For example, if a contractor puts in #4 bars at 10" o.c. instead of #4 bars at 8" o.c. in a concrete slab it's probably not going to make a noticeable difference. Should it be fixed? Of course, but if you find out about this error 3 weeks after the slab was poured then it's probably better to just find an acceptable way around it. Such as assigning a slightly lower allowable floor load or checking if there are any conservative assumptions in the design that can be pulled out.

However, one clause we include in our specifications and I encourage everyone else to do is something along the lines of "additional engineering required due to contractor errors or omissions, as well as any contractor proposed design changes or contractor requested alternatives, shall be borne by the contractor." It's really easy for the contractor to mess something up and then fight you on the time required to verify the design works with the mistake. This isn't something you should do for free. This is also a good way of persuading the contractor by establishing that it would be cheaper for the contractor to just redo a portion rather than pay a team of engineers for a week to see if an L3x3x1/4 brace is an acceptable replacement for a L4x4x1/4 brace.

As KootK said, becoming a team player is the best way to think of it but I would suggest that teamwork goes both ways. If it saves the contractor $20,000 then it would be foolish for the engineer to just reject it without investigating all the options. The other side; if the contractor wants to save $500 and an hour of labor but costs you a week of work to verify a design change then it's not cost-effective.

Maine EIT, Civil/Structural.

 

[dcarr82775]

I see a lot of engineers try something along the lines of Mighty's clause. I am not sure the legality of such a clause since there is no contractual agreement between the engineer and contractor. I have something that says if the contractor wants to change things they have to pay me to review/design as needed, but nothing about what to do when built wrong.

But my point is be careful what you ask for and how hard you want to push that. By that same logic the contractor can attempt to force costs for changes/revisions back onto you if your drawings are not clear or in error. And not matter the billing rates, our time is still less costly than the construction cost. I find it best for all involved to try to work with what is there, nitpick where it makes a difference, and only start going down the extra services road once things start to get too big to write off easily. Easier said than done of course (by me as well).

 

[TehMightyEngineer]

Completely agree with your last paragraph. I don't believe we've ever used that clause but we have referenced it many times as a way to help the contractor see the big picture and that what may seem like a small field change could actually be a huge design revision.

Maine EIT, Civil/Structural.

 

[sundale]

"additional engineering required due to contractor errors or omissions, as well as any contractor proposed design changes or contractor requested alternatives, shall be borne by the contractor."

This is a poor idea from an engineering ethics perspective, if the Contractor is not your client. It puts the SEOR in the appearance (but probably not reality) of a conflict of interest to be receiving engineering fees from two sources on the same project. This is frowned upon in most state PE Board statutes and rules.

 

[jayrod12]

I don't really see it that way sundale. In fact, if an error was made during construction I would prefer to be designing the fix myself over forcing it to be another engineer that is elsewise unfamiliar with the project.

My grandma always told me too many hands in the kitchen results in crappy food.

 

[TehMightyEngineer]

That's an interesting thought sundale.

My thoughts have always been that everyone involved would want the original engineer involved for cost and design efficiency reasons. Another engineer wouldn't have the design already done and would have to start from scratch. Also, to me the clause doesn't prohibit another engineer being hired by the contractor, it simply states "you broke it, you pay to fix it". Otherwise the designer could be left out to dry if the contractor makes an expensive mistake and then insists the design can work around it. We've lost money on small residential jobs because of things like this and thus my boss put the clause in our specifications.

As I said above, we've never had to use that clause and, if we did, I would agree that funds should pass through the owner such that only one party was paying the engineer.

Maine EIT, Civil/Structural.

 

[BUGGAR]

The original poster noted he was acting as Owner's Rep. It sounds like he has no contractual relationship with the Contractor and thus has no authority over him. He can advise the Owner that the Contractor has not met Contract requirements and he can make corrective recommendations as are relevant to his contract with the Owner. But only the Owner can "direct" the Contractor, and only within the Conditions of the Contract. (This applies to AIA, CASE, and similar contracts).

R.

 

[ChiefInspectorJeff]

As an inspector for 15 years I can't tell you how many nightmares I have seen. I was inspecting a footing for a tilt up job. The bottom of the footing was sloped 10% but I couldn't find the code that addresses that. I told the CM and he told them to level it out. from that point on they knew sloppiness wouldn't make it. But I was a tough inspector and payed the price by being attacked daily for my conscientiousness.
I think engineers should inspect their projects, or hire another party to. I have seen gas station canopy column footings poured in soft mud, shaftwalls without the air spaces,floor and roof penetrations through firewalls in townhouses,etc. ad nauseum.If there were no inspections the buildings in the US would resemble Turkey.