Return to index: [Subject] [Thread] [Date] [Author]

RE: Philosophy: Seismic Design Standards

[Subject Prev][Subject Next][Thread Prev][Thread Next]
We need to forget the principles of physics for a moment and start looking
at the problems which are pulling down the quality of construction. The
problem is not the science - it's the implementation of the science.
Prescriptive Conventional construction does not and has never conformed to
the science - it's a empirical method which bends the rules by being one of
the only code allowances that are less then rather than stricter than the
minimum code requirement. Unless we address these weaknesses we will not
only fail to improve the quality of construction but we will promote
acceptance of the lower standard by those who are in it for the profit -
especially as the gap widens because of stricter design compliance. A
building official can not simply disallow Conventional Construction. We have
debated this often - most cities don't have the clout of a Los Angeles
building department. Most officials are at the mercy of their city council
who are enticed by the revenues that a developer can bring into the city.

Here are some of the steps we need to take before we start messing with the

1. Eliminate or raise the level of prescriptive Conventional Construction to
be equal to (not less than) the minimum engineered solutions.

2. Require proof of knowledge of the Conventional Construction section of
the code by General Contractors - put it on their Contractors exam. Funny,
it's not there now and I don't know any general contractor building by
prescriptive methods who has a copy of the code or knows where the blocking
between roof joists is to occur. Homes are still being constructed with
blocking outside the plane of the bearing walls.

3. Require certification and special training of Framers and other
sub-contractors whose work includes portions of the structural system -
Concrete Subs, Plywood and Drywall subs, roofing contractors etc. Even
plumbing, electrical and HVAC contractors should have special education that
prevents them from destroying portions of the structural system (cutting
through plates, over sizing holes, destroying shear walls, over nailing or
using appropriate types of nails).

4. Create a rating system for the compliance level of each structure. THE
STRUCTURES. Buying homes is like buying used cars use to be - there should
be a Lemon Law to protect the homeowner. Builders are allowed to advertise a
high quality of construction and safety when not only does none exist but
there is no agreed definition as to what this level is. This is a must if we
are to stop developers from using the codes to line their pockets.

5. Rate insurance policies on the quality of construction. Inspection
services by independent engineers working for the insurance underwriter can
help force improvement in the building industry as certain homes become
harder to sell and developers games are uncovered. It may cost a family much
less in the long run to spend more for their home but which would cost them
less in out of pocket repairs due to damage from natural disasters.

6. Increase the education of city building inspectors to understand
structural load paths. Expect them to review those areas of framing not
specifically covered under the structural observation provisions. City
inspectors appear on the site more often than the EOR and inspect the
structure at various stages of development. Unless an unusual foundation is
poured, most structure don't require the engineer to start observation until
just prior to framing inspection in which case the damage has already been

7. Make building officials enforce stricter compliance to job specific
detailing. Sure, there are plenty of standard and typical details that
represent conventional construction standards, but most packages that I have
checked are seriously lacking in the number of details that a contractor
needs to properly construct the load path.

8. Stop unqualified professionals from crossing the line and practicing in
areas that they are not qualified to be. This includes those architect who
do not possess a minimum level of experience from testing to design
structural systems. To be fair, we must stop engineers from overstepping
their specialization from designing architectural systems unless they can
prove by exam to be competent.

9. Require certification of designers. Require a minimum work and education
level for certification and require knowledge of the Wood section of the
code for Conventional framing. This will help to insure that the level of
appropriate detailing is on the plans and make the designer liable and
responsible for his work. Most of all, this will weed out the architectural
wannabes who have only taken a few drafting course and feel competent to
design residential structures.

None of these suggestions require changes in the code, but, in my opinion
would dramatically mitigate the severity of damage that we experienced in
past natural disasters. Stricter compliance to the pure rules of physics
will not protect a family when the contractor or his sub-contractors are
deficient or incompetent.

Time is money. More and more work is being done by unskilled supposedly
under the supervision of the licensed contractor. In my experience the
unskilled labor appears on the site and the only supervision occurs when the
contractor checks in by Cell Phone to see if his men are finished and ready
to move on to the next job.

I don't understand the politics at work in any industry that protects its
incompetent members simply to avoid stricter licensing requirements. We turn
our back on the historic battle that has never been resolved between
professional organizations and individuals who don't take responsibility for
the deficiencies that exist in their profession. The construction industry
has placed quantity above quality and I firmly believe that this is the
cause of the majority of the damage that we see. The quality of construction
improves by education of those deficient in skills. As long as contractors
are allowed to obtain certification without proving their knowledge of
portions of the building code, we can not expect the damage to stop.

Reposted from 1/4/2000 "Report on Wood Diaphragm" thread. For sake of
discussion on this thread:

You can't build a strong house without a solid foundation. The contractors
and laborers in the building team are the foundation of our business. A
lower level of expectation than would be required of any professional will
not improve quality - it will only create avenues for opportunists.

We need to stop debating the rigid / flexible issues and start working with
architects, builders and building officials as a team. Each of us needs to
improve. You have to pass the basics before going on to higher education and
right now our industry is barely out of kindergarten.

Dennis S. Wish, PE
SEConsultant(--nospam--at) <mailto:SEConsultant(--nospam--at)>
(208) 361-5447 Efax