Reinforcement of existing structures
Deteriorated glue laminated tudor arch amputation
Failed tension member (Bottom Chord) - Modified bow string truss
Structural shoring services
Epoxy injection and re-lamination
Field Inspection Services
Furnish & install glue laminated structures

INSPECTION REPORT ON ROOF TRUSSES


Sample Report

West Orange, NJ
February 20, 2003

On Thursday, February 20, 2003 Dajon Associates inspected the 65' span bowstring roof trusses at the above referenced site. The inspection followed the heavy snows that fell on or around February 17, 2003 and caused on roof truss to fail. For the purpose of this report the trusses are numbered T1 through T3 with T1 located nearest the front of the building at Columbia Street. (Called East) The individual truss members are numbered from the south side of the building to the north end. The area of the truss construction is utilized as a warehouse.

The trusses are constructed with heavy timber chord members, side by side. The species is presumed to be Douglas Fir. The web members are 4" x 4" common lumber. Mechanical fasteners are ¾" through bolts at all web to chord members and 1" through bolts at splice plates and heel connections. The steel heel connection wraps around the back end of the bottom and top chords and forms a kick plate effectively tying in the 2" x 3" mechanically laminated top chords forming the bearing points of the truss.

Findings:

Truss #1: Bottom chord #1 east is badly split at the 2nd panel point this split appears to be recent in nature. A large knot in the immediate proximity of the connection is fracturing downward through the bottom face of the chord. This truss member requires remedial work.


Truss #1 Bottom chord #1 East



Truss #1 Bottom chord #1 East

Truss #2: Bottom chords #1 east and west are fractured. The web members in this immediate area as well as filler block have also fractured or split. Bottom chords #2 east and west have split at 5th panel point. These 4 (four) chord members require remedial work. The truss has experienced a "tension failure" and as a result the bottom chords fractured and pulled apart. This ultimately caused the truss drop significantly. The radius formed by the top chord has flattened out. The associated web members and splice plates will also require remedial work. The truss must be shored and properly jacked back to original elevation and configuration or as close as possible.

 


Truss #2 Bottom chord #1 East


Truss #2 Bottom chord #1 West


Truss #2 Bottom chord #2 West

Truss #3: The truss experienced a lateral force from adjoining bracing connected to the failed Truss #2. No truss members have fractured however there is some splitting seen in the bottom chords. All other truss members appear to be in good condition.


Truss #3 Bottom chord #1 East


Truss #3 Bottom chord #1 West

 


Truss Configuration

Span: 65'
Profile 9'3"
On Center: 20'
Bottom chords: 2 ½" x 9 ½" x 32'
Top chords: 6 laminations @ 2" x 3" Mech. Laminated to form radius.
Web members; 4" x 4"
W1& 22: 3' Vertical
W2& 21: 6'
W3& 20: 6'
W4& 19: 6'3"
W5& 18: 8'
W6& 17: 8'
W7& 16: 8'2"
W8& 15: 9'6"
W9& 14: 9'7"
W10&13:9'10"
W11&12:9'10"

No Scale/Half Span


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