GERRYRIGS

FIELD TEST REPORT : Our Lady of Angels Monastery Additions

This project provided a unique test setting to evaluate the cost savings potential of the GR-1 Self-Storing Component Brace and the GR-3 Self-Storing Framing and Uplift Anchor by GERRYRIGS.

The project included two roof sections each of equal span scissors and flat bottom fink trusses. For comparison purposes one section each of scissors and fink trusses were set using the GERRYRIGS, and one each by conventional methods (precut wood block spacers or 2x4 stretchers with layout, heavy toe-nails at bearing, hurricane clips, and temporary wood bracing).

Note that with the pre-installed GR-1 and GR-3 no material for temporary bracing need be procured, stocked, laid out, cut to length, handled, installed, removed, cleaned and restocked, or disposed of.

No material need be passed up to truss installers to become a falling hazard to those below, nor must installers handle material in elevated workspace.

No additional operations such as installation of separate hurricane clips or bracing to maintain layout for ceiling materials are required.

Accurate layout is assured and functional stability of the truss system is achieved at a quick and positive pace, increasing safety while reducing labor and expensive crane time.

GR-1 can also be used and pre-installed for Continuous Lateral Bracing of Web Members as required by the truss engineering.

Note: typical truss design on this project was: 18 ft span; 12/12 pitch;

16” overhang

Reported Results of Time and Material Requirements:

Fink Truss System with GERRYRIGS :

Crew: three men in the roof, one man with the crane

GR-1 pre-installed per BCSI Standards* on the top and bottom chords

GR-3 installed on the bottom chord at bearing layout by the crane carpenter at time of lift.

36 trusses were set, anchored at bearing and braced to perfect layout at both top and bottom chords in a total of 2 hrs and 20 minutes or about one truss set every 4 minutes.

No Additional Operations were required

No inherent Safety Hazards were noted

Labor Cost at $25 hr: $240.00.

Material cost for GERRYRIGS: $424.00

Cost of additional operations: $0.00

TOTAL COST TO SET 36 FINK TRUSSES: $664.00

Fink Truss System with conventional bracing methods:

Crew: four men in the roof, one man on the deck, one man with the crane

Temporary Bracing System: precut 2x4 blocks passed up from the deck

30 trusses were set in approximately 3 hrs or about one truss set and temporary braced at the top chord every 6 minutes.

Additional Operations Required: 1) procure and handle 2x4 bracing material on site; 2) pre-cut 2x4 blocking to length; 3) stock blocking to erection site; 4) pass blocking up as needed; 5) install blocking to space and brace the trusses as set; 6) remove blocking as plywood is installed, dropping to floor or ground; 7) gather blocking for re-use or disposal; 8) de-nail blocking if re-used; 9) install hurricane clips at truss bearing; 10) install bracing of bottom chord to stabilize and set layout: (labor, 7-9 hrs.)

Temporary Bracing Material Requirement (if braced to BCSI Standards*): approximately 25 2x4x12’ plus hurricane clips

Inherent Safety Hazards: falling material as blocking is passed up to truss installers; nail puncture from discarded blocking; damage to trusses from heavy toe nailing; lack of truss system stability if temporary bracing is not installed to BCSI Standards*

Labor Cost at $25 hr: $450.00.

Material Cost for Temporary Bracing and clips: $115.00

Cost of Additional Operations: $225 (9hrs @ $25 hr)

TOTAL COST TO SET 30 FINK TRUSSES: $790.00

SUMMARY COMPARISON OF FINK TRUSS SECTIONS:

GERRYRIGS: 36 trusses @ $664 = $18.40 per truss

Time elapsed: 2.33 hrs (4 man crew)

No Additional Operations

CONVENTIONAL 2X4 BLOCKING TEMPORARY BRACING, PLUS ADDITIONAL OPERATIONS:

30 trusses @ $790 = $26.33 per truss

Time elapsed: 3 hrs (6 man crew), plus Additional Operations (9-10 hrs)

SAVINGS = $7.93 per truss

EQUALIZED COMPARISON AT 36 TRUSSES:

GERRYRIGS: 36 @ $18.40 = $664.00

Conventional: 36 @ $26.33 = $947.88

NET SAVINGS by use of GR-1 and GR-3: $283.88 (29.9 %)

Scissors Truss System with GERRYRIGS:

Crew: four men in the roof, one man with the crane

GR-1 pre-installed per TPI Standards* on the top and bottom chords

GR-3 installed at bearing layout by the crane carpenter

16 scissors trusses were set, anchored at bearing, and braced to perfect layout at both top and bottom chords in 40-60 minutes, or about one truss set every 3.75 minutes.

No Additional Operations were required

No Inherent Safety Hazards were noted

Labor Cost at $25 hr: $125.00 Material Cost of GERRYRIGS: $240.00

Cost of Additional Operations: $0.0

TOTAL COST TO SET 16 SCISSORS TRUSSES: $365.00

(Note: crew size could easily have been reduced by one)

Scissors Truss System with conventional bracing methods:

.Crew: four men in the roof, two men on the deck, one man with the crane

Temporary Bracing System: 2x4x12’ stretchers with 24” oc layout, passed up from the deck

16 scissors trusses were set, toe-nailed at bearing, and temporary braced at the top chord only in about 1 hr, 40 minutes, or about one truss set and braced every 6.25 minutes

Additional Operations required: 1) procure and handle 2x4 bracing material on site: 2) lay out 2x4x12’ stretchers at 24”oc; 3) stock bracing material to erection site; 4) pass the bracing material up to truss installers as needed;

5) install the stretchers with adequate “overlap” to support the extended length of the 2x4; 6) remove the stretchers as the plywood is installed and pass to the deck or ground; 7) de-nail the 2x4x12’ stretcher material and stock for re-use; 8) install hurricane clips at truss bearing; 9) install 2x4 bracing along the bottom chords of the trusses to stabilize the system and to set the layout for the ceiling materials: (4-5 hrs @ $25)

Inherent Safety Hazards: falling material as bracing is passed up to installers and handled in elevated workspace; nail puncture from discarded bracing material; damage to trusses from heavy toe-nailing; lack of truss system stability if temporary bracing is not installed to TPI Standards*

Labor Cost at $25 hr: $290.50 Material Cost: $72.00

Cost of Additional Operations: $125.00

TOTAL COST TO SET 16 SCISSORS TRUSSES: $487.50

SUMMARY COMPARISON OF SCISSORS TRUSS SECTIONS:

GERRYRIGS: 16 scissors trusses @ 365.00 = $22.88 per truss

Conventional: 16 scissors trusses @ $487.50 = $30.46 per truss

SAVINGS $7.58 per truss

NET SAVINGS by use of GR-1 and GR-3: $122.50 (25.15%)

NOTE : The erection of scissors trusses is typically a more difficult operation than for simpler flat bottom truss designs due to the elevated “space” of the cathedral or vaulted ceiling profiles and the limited area of bottom chord bearing. Use of the GR-1 on the top and bottom chord and on specified web members allows stabilization and precision spacing of the scissors truss system in a single operation, without the need to erect scaffold or to thread bracing into the trusses from below. Use of the GR-3 at truss bearing guides the truss into correct position readily with no back and forth slippage across the supporting wall or beam.

NOTE : With Conventional truss erection procedure, required hurricane clips are often installed “whenever” and not necessarily at the time the roof is built. In the scissors section braced conventionally on this project, soffits were built to house recessed lighting. Because the hurricane clips had not been installed at the time of truss erection, their placement became a much more arduous and time consuming task performed through the lighting soffit structures. This simple example is not uncommon and underscores the “single-operation” efficiency of the GERRYRIGS system with the GR-1 and the GR-3.

NOTE : Depending on the size of the job, the time saved by use of the GERRYRIGS GR-1 and GR-3 would reduce the cost of Crane Rental once exceeding any “flat rate fee” (ie: crane rental based upon 4 hrs p-p)

NOTE : The 18 ft span of the trusses on this project, even at a 12/12 pitch, presents a relatively easy erection by any method. The Advantage of using the GERRYRIGS System is proportionately greater and more important, the larger span dimensions and truss area become.

*BCSI (Building Component Safety Information) Standards have been compiled and published by the WTCA (Wood Truss Council of America) and TPI (the Truss Plate Institute). These standards describe industry accepted “best practice” methods for the safe installation and stabilization of metal plate connected wood floor and roof trusses.