Perception 7

[jike]

How do you overcome an inaccurate perception by potential clients that we overdesign wood frame buildings?

There are both architects and engineers in our area, that are not following the governing code, IBC 2000. Apparently the state plan review does not pick up on these omissions either. These buildings do not use shear walls, holdowns, eave blocking, collectors, etc. They are built like houses with literally no structural calculations except perhaps headers.

Of course, contractors say we never build it this way and clients realize that they can get a cheaper building by hiring xxx Architects.

 

[damstructural]

Your description implies that the minimum prescriptive standards for non-engineered buildings are not being met. Why is the "state" reviewing plans? This is typically a local jurisdiction function.

In CA we hear the same thing, but I see more and more plan checkers requiring engineering for even small remodels. We seems to be headed in the other direction here.

This topic is the crux of Performance Based Engineering. The owners need to know that the codes are designed for life safety purposes, not to limit damage under extreme loading. We should be asking the owner some questions like: how is your risk tolerance about patching drywall and stucco every 10 years? Are you ok with finding your roof in your neighbors yard after a 100-year wind event (~25% chance loading in a 30-yr mortgage period)?

As for convincing evidence, read the Northridge & Loma Prieta EQ reports about damage to older wood frame buildings. Garage portals and porches collapsed, stucco and drywall damage everywhere, and many poorly-anchored buildings separated from their raised foundations. You might not be subjected to these kinds of loads in your area, but then again, the accelerations were not all that high in most of these cases.

A great visual is watching a full-scale two-story building in cyclical testing at the new Simpson Test Facility in CA.

http://www.strongtie.com/strongwall/testing.html

Having said all the above, I also believe that we are probably over-designing in many cases, but the cost of doing so is far less than the realtor's commission, and not a bad investment. It tends to balance out with poor construction and inspection practices.

Maybe engineers need a better background in sales.

 

[pmkPE]

If one reviews the code, prescriptive designs are what the majority of the public, which includes contractors and potential clients know about "design". If a structure is built according to the prescriptive requirements of the code, the structure should serve the owner well even through adverse conditions such as heavy snows, hurricane winds and/or seismic events. If you have the time, try analyzing a typical prescriptive wood frame structure and see what the stress results are. I have not done so in total but have had to evaluate portions of prescriptive construction. In my opinion it seems that the codes are being rewritten to make up for the fact that structures are not being built according to/in conformance with the codes. The onnous therefore would be for the inspection/approving agencys to do a more thorough job and enforce the codes. For example, after Hurricane Andrew devasted Florida the APWA did a review of the failures of roof sheathing affected by the storm. Much of their findings were that the original construction was deficient, not that the prescriptive requirements of the applicable code in affect at the time of the construction were inadequate.

Also in regards to "others" not designing per code. How do you know this to be true? Have you checked "their" calculations? Have you spoken with "them" regarding "their" assumptions? Could you and would you testify in a court of law and show that "they" are not designing to code? If so you should report "them" to your states registration board for investigation. And, if a structure(s) is under construction that potententially threatens the life, health and/or safety of the public, then you should also report this to the governing authority that issues certificates for occupancy, before they allow people to use the facilty. But only after you are absolutely positive in your "facts" and evaluation.

Engineers must police themselves. However, unless I just happen upon a job after construction, or intentionally investigate projects under construction I would not be able to say (in a court of law) that "they" are not designing to code. It would take an enormous amount of my personal time to even evaluate someone else's design let alone compile data to show that they are not meeting the code. I would also assume first that "they" are professionals and therefore "their" side needs to have a chance to speak for "themselves".

This is not to say that there are not unscrupulous "practitioners" but before accusing anyone there should be sufficient cause for concern. Backed up by evidence that not only you believe is valid but also that your peers would agree with.

 

[Lutfi]

In my firm, we do not design homes!!!! Unless they are the good size ones (1 million or above). No one will pay a structural engineer the proper compensation to do the proper job and design.

Like you said, you will never win because builders will tell you this is the way we always done it. The clients tend to listen to them and the engineer wind up looking bad.

In my humble opinion, I think we as engineers, we must work better at improving our images. I can write forever on this subject. We are our own worst enemies some times.

For example, there are engineers in my area, in Florida, who will stamp plans for around $200 per house. Now we all know it takes much more effort to run wind loads, design trusses, roof diaphragm, gravity, walls for wind loading (in plane and out of plane), footings, and some other details than $200.00. So, when we design for such little money, it is safe to say that quality will suffer.

A contractor sued me once because bridge girders (timber, in the boonies which means they will not be maintained as required) were designed to 60% of their allowable capacity! I insisted on my design and I left at that. Public safety is paramount for structural engineers. We should never compromise and let go of that trust.

I think you have much better image if you stick to code and good practice. You can improve you image by not doing business with such characters. It is this simple.

 

[jike]

We do not design homes either. These are commercial grade buildings, say 25,000 sf and above. These buildings are not allowed to be designed or built without a structural engineer.

Unfortunately, our state is just starting to come out of the dark ages where they have allowed house type construction for commercial buildings (ie no shear walls, no holddowns, no eave blocking, etc.). As a result the competent structural engineer takes the brunt of the critisism from clients and contractors. The architect or green structural or civil engineer doesn't know the code requirements.

Since I am part of an A/E firm the architects want this work but think that a wood truss designer is the only person besides the architect needed to design a wood frame building. A structural engineer is really not needed. Afterall, it is just an oversized house.

 

[dozer]

$200 per house!!?? Sounds like somebody is plan stamping. When there's people like that out there that just wave their magic wand over a set of drawings and proclaim them blessed, its no wonder lay people regard engineers who actually do some structural checks as overly cautious.

What bugs me is why don't they regard the people doing a half-a** job with suspicion? I'll tell you why, because these people are easier on their wallets. (At least until something fails.) I could go on and on, but I'm afraid I might have stroke.

 

[unclesyd]

dozer, Lutfi,
The $200.00 Stamping job is by the secretary, it's $250.00 if the he wields the stamp and $300.00 if he actually signs it instead of using a signature stamp.

I live in N.W. Florida and this practice is rampant and I think getting worse. The problem is a house will hold togather just long enough for the builder to go out of business and relocate. It's not only the engineering that doesn't go into a project, it starts earlier and covers nearly every aspect of home construction.

The same goes for steel erection especially of packaged buildings, some fairly large. I get first hand reports and have actually went and looked at a structure and the problems that had been conveyed to me. Usually by a question, is this right, why are they doing it this way, how would you correct this, and so on.
The latest was two BOBCATS, one on each outside wall pulling in opposite directions to plumb the columns in 70' long walls. The only problem was that all the bolts had been tightened and a good percentage of the diagonals were installed. They didn't get it plumbed while I was there, the angles on the cables was a somewhat less than 45°.

I think things are getting worse in every aspect of the construction industry, schools to, or most any industry. Work practices and standards are being factored, as in algebra, brought to the lowest common denominator. I've stated this before, bad practices are perpetuated and improved on, in the negative, and good ones are ignored or discouraged as a pain in the butt.

I can't say this just started as in my first meeting, some sort program of employee involvement, I had with the Dept Heads. Everyone had a little list of things they were concerned with as we had been told to come prepared to ask questions.
The first statement from the Research Director's mouth was:
I want you to remember that for everyone of you sitting here there are two people hanging on the fence that want your job, good day. You could hear the paper crumbling and this was 1959.

It is just like my father told me: When you are born into this family you are born poor and ugly and go down hill the rest of your life. It took me a long time realize how prophetic he was and then it was too late to do anything. I hope engineering and the trades don’t suffer this progression as there are a lot of good people still trying to do a good job correctly and leave a makers mark.
A witness mark, not as a witness.

 

[3dboy]

This kind of B***S*** from the builders is typical. The best way you can deal with this is summed up by a comment my brother in law made a week ago. Someone said "I wish engineers could work a week in the field so they can see how hard it is to do what they want" and he retorted, "I wish every contractor would revisit every job he does to see what kinds of problems he left when he finished." the fact of the matter is we need to tell clients directly that they get what they pay for and if they want an unsafe crappy building that is their perogative. We have to design safely and to the code no matter what. As for these plan stampers, we need to be more active in our professional organizations and institute stiff penalties for this kind of crap. Not only does it make it tough for honest engineers to make a living, it is flat out dangerously unsafe.

 

[samdamon]

Jike-

I hear you. The issues you discuss are not just with wood buildings, although I think the inaccurate perceptions you describe are usually far worse for wood projects than those made from other types of materials.

We have a fair number of existing low-rise one- and two-story commercial wood structures in this area, and more are going up all the time. Wood is getting to be a “hot” material right now because the cost of steel and concrete are so unstable and high.

I would rather design a wood building than any other type, because timber can be a renewable resource, but there are so many obstacles to getting a correctly designed and built structure in wood, you need to think about even taking the work.

In my area, there are designers who issue drawings that don't comply with the code, but they seem to get away with it regularly. Even though, for certain building uses (for example a medical office building) both a local and state review of the plans is required before a permit is issued. If done in wood, these types of buildings can be large enough that they can not be designed prescriptively and must adhere to IBC 2000.

We have found that despite review of building plans from two sets of eyes from two jurisdictions, plan reviewers frequently miss major structural items in wood buildings, especially regarding lateral force resisting issues. This year, so far I have seen wood framed office building plan sets prepared by three different professionals with no discernible lateral force resisting system. None. And these buildings got permits.

No shear walls (or place for any), no hold downs, no way the diaphragm works because the aspect ratio is way off, missing load paths between adjacent diaphragms or between diaphragms and shear walls, no chords for the diaphragm, no connections for holding down rafters with uplift, the list goes on and on. Calculations are not required to notice these things, they are basic. But they get missed by the reviewers.

I get to see this stuff because my office sometimes does fit-outs for building shells that have been designed and erected only one or two years earlier. We see all kinds of crap, from both Engineers who should know better, and from Architects who clearly have no clue what they are doing. As you have pointed out, there are professionals out there who are willing to seal the most rudimentary, schematic drawings you can imagine and call it a finished structural design. And they get permits. I have theories on why this happens, but that’s for another post. In the end, it is impossible to compete against such practices.

Our direct experiences when working on new wood building designs have generally not been favorable either. I have had more than one Architect complain about “over design” when I request the necessary shear walls and hold downs. (“But this is not much bigger than a house” I have heard). Their eyes get cloudy when I start talking about drag struts or seismic forces, overturning moments, etc. At our office we are very willing to cheerfully explain the why’s of our designs, (after all it’s very interesting to us) but in the end what we are really doing is trying to teach something of our profession. However, our clients are not really interested. Not really. They want their drawings, and please don’t be too conservative (i.e., don’t follow the code too closely).

Connection design for even relatively simple wood buildings can also easily consume many more hours than expected. Despite the availability of prefabricated connectors from Simpson and USP, situations frequently can arise that require something custom. I find this to be especially true when connecting structural ridges and valley girders together in a roof with varying hips and gables.

During the construction of a wood building, builders will tell the Owners and also complain to the Architects that the Engineers have over-designed the structure. The builder has no responsibility for the fitness of the structural design, and may not have a clue, but he usually has the Owner’s ear. I sometimes think that Contractors only measure square feet when they bid on a set of plans, but then they get really cranky when the Engineer requires them to actually follow the details during construction. When the Builder gets cranky, the Owner gets cranky. Then the Architect hears about it and gets cranky. Then we hear about it. It can get to be a regular cranky-fest.

Funny things can happen. On one very substantial building, when we continued insisting that the second floor diaphragm needed to extend all the way to the exterior wall plates as shown on the drawings, we were thrown off the job. On another, when the Contractor asked about why there had to be eave blocking, the Architect told him to not to install it, and didn’t bother to tell us about the question.

Quite often we have limited access to the Owner and it’s difficult to reverse the impressions he has due to what the Contractor has whispered to him. This dynamic gets really bad when the Owner is also the builder, which I see more often these days. It is also magnified in wood-framed construction, because many individuals who have a background in residential work think that is sufficient to allow them to judge the design.

Some suggestions, Jike: Don’t normally pursue commercial wood design work. If you have to work on a new or existing wood building do it only as a favor to a valued client. Structure your fee conservatively. Hew as closely to the code as you can and try to explain why. Insist on periodic field review as part of your Scope with wood. If the existing design of a wood building you're modifying obviously doesn’t work, say so, let the chips fall as they may, and let the other designer clean up his own mess.

 

[Ron]

Another Floridian in the mix here....
One thing that is often forgotten in evaluating the "performance" of existing structures is that very few of them ever get stressed to their design capacities. When we see damage to structures from a wind event, the early assumption is that it was a localized condition that exceeded the design. As a veteran of many failure investigations of different types, I see more failures caused by improper construction than improper design. Failures are usually sequential, and when that one weak weld fails, the anticipated design stress path gets blown to hell. Each part of a building counts. It's important that attention be given to proper design/construction/inspection of ALL the critical parts.

Overdesign is perhaps the safest way of compensating for the inevitable construction deficiencies, whatever their cause. When we design to the minimums, we invite disaster because we know that construction is already employed to the minimums.

 

[damstructural]

Performance-Based Engineering is a tough sell for "typical" buildings which, as stated above, don't often see extreme loads during the owner's window of concern. We as engineers, on the other hand, buy the building design for our entire career.

Anyone stamping plans for $200 should have their license confiscated. In CA the plan checks are getting steadily tougher, so I can't imagine anyone getting away with that for very long.

With seven years of framing experience, I can often find little ways to improve design efficiency, but it usually takes extra attention and design time on my part. That's been my niche on custom homes to keep my fees where they need to be. I've been fortunate to work closely with owners and contractors with very few complaints.

Overbuilding is a poor substitute for shoddy construction. Its a bad situation when that's our only option.

 

[pmkPE]

I see many complaints and they seem to be in agreement. Now what? Complaining among ourselves is not enough. Do your state registration/licensing boards have means for rectifying these situations. Perhaps your states attorney general will accept your complaints and investigate. Do your states have licensing requirements for contractors? Anyone with ideas or better yet knows of examples that have worked in their state?

 

[jike]

I have been told by another that has practiced in an area where peer reviews are required that this has a tendency to level the playing field. Architects and Engineers that are not following codes quickly discover that they can no longer get away with doing it the old way. Everyone is brought to a higher level as they now know what each other is doing. The ones not following the codes will be required to modify their designs.

The Owners, Contractors and Developers can no longer exploit the different contract documents by using the Architect or Engineer with the least info. on his drawings.

I see mandatory peer review as one way to help this problem. What are the disadvantages of peer review other than cost to the Owner?

 

[vmirat]

Since money is the motivating factor for insufficient design, I think there should be a way of putting the responsibility on the owner. If they face some form of penalty for accepting work from their consultant that is below code standards, their would be a lot less of this happening. I suggest we all contact ASCE and get them to lobby for us. I hate to say this but, maybe protection of public safety and property (i.e. building codes) should be at the federal level instead of at the whim of each state.

 

[jike]

The Owner is not knowledgable enough to know whether a design meets code requirements or not. Contractors and Owners do, however, know who they can go to, to get the design that can be built the cheapest.

I do not feel that ASCE lobbying efforts are particularly directed toward benefiting Structural Engineers since we are a small portion of the larger group. This is part of a problem that could be discussed in another thread.

 

[samdamon]

Jike- Agree that mandatory peer review would be a big step towards reducing the problems I discussed earlier. Here in the Northeast I think peer reviews are only req'd by Connecticut for certain sizes of structures. (A parking garage collapse created the impetus for CT to put peer review into the law).

Mandatory peer review would add cost and time to a building schedule though. Would be a tough sell to the entire building community. The thing is with seismic and wind loads that buildings that don't meet the code required resistance may still stand for years and years, so non-engineers (perhaps understandably) will wonder what the big deal is. But for me, if the building doesn't meet the lateral resistance requirements of the code (whether built in wood or any other material), then I haven't done my job, and it simply is not in my make-up to do anything less.

We all complain that the codes are getting more complicated and that the lateral forces keep going up, but I'm not going to be the engineer who is going to ignore the changes and just keep designing for 20 psf wind like they did in the 70's.