Need a book? Engineering books recommendations...

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

handrails and trusses and bears

[Subject Prev][Subject Next][Thread Prev][Thread Next]

Detailed in the FBC, so I am sure the same goes for the IBC and other codes.
Very specific guidelines , so I would consult the code. Since the FBC and
IBC are very similar, in the FBC it is in CHPT 10. FBC says circular OD =

A & E Firms

We are an A & E firm, but we only advertise (as far as I know) that we are
capable of civil, roadway, structural, and arch, all of which we have
licensed staff in house. The unclear thing is we may lead on that we do
complete building design, in that, we have sub-consultants for MEP. We do
not have any MEP terms in the name of our business. Many MEP firms go with
generic names like "ABC MEP Consultants" or "Consultant Engineers" or
something that doesn't lead you on too much to what they do.

Truss Bracing:

This has been a often talked about subject at our office since we do lots of
low rise with pre-engineered trusses on a good portion of buildings we do.
Lately I have been putting a note on our framing plan requiring the truss
fab to provide "truss to truss calcs, and all bracing design and
connections", and then I require them to provide me with the bracing details
and the reactions and then I will design the connection to the main
structure or the roofing system.

I think this , in theory, works the best for a few different reasons. Some
truss fabs, and I have seen it on my jobs, will design these 10ft deep
trusses with as few 2x4 webs as possible, and then require tons of bracing
by the contractor, that I am supposed to design. Then the contractor doesn't
do it or doesn't do it properly, and if he does, at a pretty intensive labor
cost. Requiring the truss fab to design and provide the bracing will in my
mind make them design their trussed to require as little bracing as
possible, probably eliminate any web bracing. No web bracing usually only
leaves the bottom chord, assuming you have a deck or sheathing attached to
the top chord. Also if you have gyp board or other similar rigid material,
some codes allow you to count that as lateral bracing, so then the bracing
issue goes away. But I agree, who better to design the bracing then the
truss fab? They are THEIR trusses that they designed and provide the layout
for, who better to design the bracing then them? I think it is complete BS
that they try to shove that responsibility onto the EOR. Their claim is they
are not designing the building so they don't know about how to connect the
bracing, etc. But according to my note they need not worry about that part,
just include bracing diagrams and loads to me during the shop drawing
process and I will provide the final connection design.

Well, so far, this has not worked out so well. The fact is that I think that
a good chunk of the truss industry is a bit of a scam, in that they have
technicians who "design" the trusses using boiler plate software, then send
the "design" off to the software company or whoever they lease it from, or
some local engineer , who blindly stamps the computer printed calcs. Do you
think the engineer who signs the trusses actually supervised anything? I
know from firsthand experience this is the way a  lot of truss companies do

But I am going to start holding their hands to the fire and making them.
Especially since it is on our CDs and they bid on it. So the claim that "Our
computer program cannot do this design" or "We are not set up for this work"
or even sending me a copy of some TPI document or something to get them off
the hook, is not going to cut it. Fact is, if it is on the CDs saying THEY
have to do it, and they bid on it, then THEY have to do it.

We are in the middle of a design-build on a single story buidling with a
large, complicated trussed roof. We are working with a metal truss fab who
has an engineer in the office or a sub who does all connection design (even
to main structures), bracing, trusses to carry shear parallel, transfer of
shear from the edge of the roof diaphragm lateral to the trusses into the
bond beam- EVERYTHING. They submit shop dwgs and calcs for everything, and
if we did not like their connections or something, we had a chance to change
it. They have our full set of dwgs so they know they are connecting to
steel, CMU, or concrete. We even added steel top plates to beams to
accomodate their trusses. They bid it appropriately and are prepared to do
the work properly. This is the way it should work. This is the way we hope
for it to work in the future. We will certainly continue to word it this way
in the plans and require the truss fab to supply all bracing. I also think
overall this will be more economical and faster for the client and GC.

Andrew D. Kester, EI
Structural Engineer
Bentley Architects & Engineers
665 W. Warren Ave.
Longwood, FL 32750

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at:
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*   Questions to seaint-ad(--nospam--at) Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: 
******* ****** ****** ****** ******* ****** ****** ********