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Roof Truss Failures
February 6, 2019
1:33 am
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bestroofingsolutions2018@gmail.com
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The right way to find and hire a contractor is to make a checklists that assists you find out what you are looking for. Building hope start with looking at how good a Roofing Contractors in Chennai fits your needs.

September 22, 2009
3:31 pm
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alabamatide
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VT...hahahahah!!!!Nebraska...hohohohoh!!!Almost the top 10...hahahahah!!!

Sweet Alabama! The Tide is starting to Roll!! 😀

September 22, 2009
12:31 pm
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hokie81
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Tide: I will concede the loss to your sorry team from Alabama, but we came back to beat BIG RED from Nebraska and now we are almost in the TOP 10 rankings in the Country !! Cool

September 22, 2009
12:07 pm
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bbolduc
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From the photo it appears that either the plate was never properly pressed into the wood or the truss was severely mishandled (probably during installation). I suspect that both may have occurred.

In any case, the truss needs to be repaired using a repair designed and sealed by a professional engineer. The other trusses on this job should also be inspected to insure that they do not have a similar problem.

The tooth embedment gap tolerances allowed during manufacturing are specified in ANSI/TPI 1 as:
Zero up to 1/32? ? 100% effective
up to 1/Construction exceeding the minimum requirements6? ? 60% effective
up to 3/32? ? 40% effective
over 3/32? ? 0% effective.

These limits were likely exceeded during construction of the building.

September 14, 2009
8:04 pm
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drp
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LOL :p 😀

September 14, 2009
2:28 pm
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alabamatide
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OK DRP and VT, eats time for you both to eat crow! I''ve been gone, but not forgotten!! LMAO!

The Tide is back. And as long as we kick the crap out of Auburn it will be a wonderful year, Obama not withstanding.

Alabama, I love you!

September 3, 2009
1:16 pm
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charlie1929
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the BCSI catalog describes the bracing of the truss system,and i do not see anywhere in their catalog where it says to use 1x4 bracing, however thats all i have ever seen in residential roof trusses.whats going on?

September 3, 2009
12:59 pm
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garth dreger pe
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Boo1, the Building Departments and inspectors should be qualified to review the MPT drawings for the building code. i.e. per the IBC Section 2303.4 Trusses or the IRC section R801.10 Trusses and that they comply with the plans code, loads, etc. The inspectors should also be able to verify that the trusses placed match the truss design.
What they should not be doing is approving the truss designs and layout, that is for the truss engineer to do when the truss designs are sealed nor that the truss designs comply with the plans, that is for the building designer to do.

September 2, 2009
6:32 pm
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jdrobysh
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Boo1 -

Are you asking about field inspections during construction of a building?

Or are you asking about factory inspections at the manufacturer?

The assembled units are approved when they arrive at the job site. We need to inspect for obvious defects due to improper handling, proper erection methods (always try to watch at least part of the set to verify proper methods are used), bracing per the approved drawings, attachment per approved drawings. There is also a referenced standard for them.

We don''t need to understand or be able to reproduce all the calcs. Verify they are reasonably accurate to the best of your knowledge. A Code Official SHOULD know the snow loads for his jurisdiction, the basic wind speed, specific live and dead loads per code.

Would it be nice to know ALL of it? Sure.
Is it necessary? No.

Can an Engineer justify what appears to be ''less'' than required? Sure.
Will some try to bamboozle the AHJ? Unfortunately, yes. But not too many, and you get to know them quick.

September 2, 2009
2:27 pm
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boo1
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People that sign PE or SE at the end of their name should be qualified to inspect MPT systems.

What code can we inspect MPTs too? MPT are engineered systems.

Do we understand the program inputs and assumptions, who checks the grades of lumber in MPTs, are we checking for load paths, do we understand how to resist the perpendicular and lateral component loads (I assume we do understand the uplift, blocking and nailing)?

September 2, 2009
1:12 pm
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jdrobysh
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sp_Print Print Post Post #11

Boo1 -

I think you mean we''re not qualified to DESIGN them... If we''re not qualified to REVIEW them, who is?

September 2, 2009
11:26 am
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boo1
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sp_Print Print Post Post #12

Garth, neither the building departments nor the building inspectors are qualified to review MPT engineered systems.

September 1, 2009
4:15 pm
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george roberts
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sp_Print Print Post Post #13

Uncle Bob is on a roll.

"There is no excuse for sending untrained inspectors to a building site."

Inspectors do not need to know everything, but they do need to know what to look for in the buildings they inspect.

September 1, 2009
2:35 pm
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garth dreger pe
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sp_Print Print Post Post #14

Here in the Phoenix, AZ area, on commercial buildings, many Building departments require the truss designs and layouts to be reviewed by the building designer. I have reviewed and red-lined many sets of truss calculations to ensure they meet the intent of the building plans. For residential buildings this review by the building designer should also be done. Neither the building department nor the building inspectors should be taking on this responsibility. IMHO

August 26, 2009
4:34 pm
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pyrguy
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We always had the address on the truss plans.

The address on the permit did not always match the truss drawings.

😀 😀

August 26, 2009
2:09 pm
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rosso
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sp_Print Print Post Post #16

Frank,

Thanks for the reminder;

"Different truss configurations bear differently on the walls etc. below."

Major home builders often use the same "basic" foundation and plan format for 5 or more different configurations; with different room configurations; and as you stated different "bearing walls".

The builder''s supervisors would try to provide old truss drawings for different room configurations; "which didn''t work". They depended on the inspector not knowing the difference; and they were right in most jurisdictions in the area.

I contacted the truss manufacturers and they started putting the building address on the truss design drawings and laminating over them.

Another reason the inspector should know how to read the drawings and instructions; and know how to inspect truss systems.

Uncle Bob

August 26, 2009
9:58 am
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frank castelvecchi
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sp_Print Print Post Post #17

Here no sealed truss drawings with bracing instructions = no permit issued.
Different truss configurations bear differently on the walls etc. below.

August 26, 2009
9:29 am
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constructionarbitrator
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[QUOTE] "Architect said"....most of the RI local jurisdictions AHJ''s REQUIRE the submission of FULL TRUSS ENGINEERING AND LAYOUT prior to permit issuance. [/QUOTE]Architect:

Interesting that little Rhode Island requires truss plans before permit issuance, here in the California Bay Area where *everything* is required to have an engineers'' stamp, they all just note that "Truss engineering be provided by truss manufacturer." And I''ve never seen an AHJ require it prior to permit issuance, in fact I can recall rubber stamp notations on my plans stating "Truss engineering to be provided prior framing inspection" (or something to that effect), and handing the engineering to the field inspector at the time of the frame inspection. Of course he never looks at them, he takes them for "The File".

August 26, 2009
7:13 am
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rosso
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sp_Print Print Post Post #19

Boo,

The responsibility of the truss drawings being correct belongs to the Truss Designer; not the plan reviewer.

The Tuss drawings and individual truss sheets; to the inspector; are really installation instructions. The inspector uses them to make sure that the trusses are installed in the right location; and that they are installed correctly; in accordance with the truss design drawings; or BCSI 1-03.

2006 IRC, R802.10.1 (extract) Truss design drawings shalll be provided to the building official and approved prior to installation.

The approval part for us; was that they be stamped by the design proffessional.

Note: "Prior to installtion"; not, prior to permit or start of construction of the building; which to me was that they were in a packet, on site when I arrived to inspect.

"Is it fair to expect our inspectors to check complicated engineered truss systems?"

It''s not only fair; AHJs should require their Building Inspectors to take the WTCA courses and learn how to inspect the installation. It is not difficult; and any inspector who has a building inspector''s certification should have no problem learning.

Taking the online course is simple and the instruction method they use makes it easy to understand.

In fact; there is no excuse for a building inspector not knowing how to inspect the installation of wood truss systems.

http://ttw.sbcindustry.com/inspector.php

There is no excuse for sending untrained inspectors to a building site.

Uncle Bob

August 26, 2009
6:32 am
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boo1
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sp_Print Print Post Post #20

Were lucky to see a one sheet truss layout showing the load bearing walls at permit issuance. What if the contractor subsitutes a different truss set during construction? Who is qualified to review the truss sheets? Who checks the as delivered truss to the cut sheet?

Is it fair to expect our inspectors to check complicated engineered truss systems? If you dont think todays trusses are complicated...