SECTION 06136

HEAVY TIMBER TRUSSES

PART	GENERAL

SECTION INCLUDES

Heavy structural timber trusses.

Bridging, bracing, and anchorage.

Connection hardware.

[Preservative treatment of wood.]

PRODUCTS FURNISHED BUT NOT INSTALLED UNDER THIS SECTION

Section 03100 - Concrete Formwork: Placement of steel support devices.

Section [______-____________]: Placement of steel support devices [embedded] [bearing upon and anchored] into masonry.

RELATED SECTIONS

Section [_____-_________]: Setting anchors in [concrete.] [masonry.] [________.]

Section [_____-_________]: Prefabricated [steel structural supports.] [________.]

Section 06112 - Framing and Sheathing: Structural dimension lumber framing.

Section 06114 - Wood Blocking and Curbing: Miscellaneous wood blocking, spacers, and bridging.

Section 06125 - Wood Decking.

Section 06131 - Heavy Timber Framing.

Section 06181 - Glued Laminated Structural Units.

Section 06193 - Plate Connected Wood Trusses.

Section 06196 - Plywood Web Joists.

Section 09900 - Painting: Site finishing.

REFERENCES

AITC (American Institute of Timber Construction).

ALSC (American Lumber Standards Committee) - Softwood Lumber Standards.

ASTM A36 - Structural Steel.

ASTM A47 - Malleable Iron Castings.

ASTM A123 - Zinc (Hot Galvanized) Coatings on Products Fabricated from Rolled, Pressed, and Forged Steel Shapes, Plates, Bars, and Strip.

ASTM A167 - Stainless and Heat Resisting Chromium-Nickel Steel Plate, Sheet, and Strip.

ASTM A446 - Sheet Steel, Zinc Coated (Galvanized) by the Hot-Dip Process, Physical (Structural) Quality.

AWS D1.1 - Structural Welding Code.

AWPA (American Wood Preservers Association) C2 - Lumber, Timbers, Bridge Ties and Mine Ties - Preservative Treatment by Pressure Processes.

AWPA (American Wood Preservers Association) C20 - Structural Lumber Fire Retardant Treatment by Pressure Process.

NFPA (National Forest Products Association) - Grading Rules.

NLGA (National Lumber Grades Authority) - Grading Rules.

RIS (Redwood Inspection Service) - Grading Rules.

SPIB (Southern Pine Inspection Bureau) - Grading Rules.

TPI (Truss Plate Institute) BWT-76 - Bracing Wood Trusses.

TPI (Truss Plate Institute) HET-80 - Handling and Erecting Wood Trusses.

TPI (Truss Plate Institute) PCT-80 - Design Specification for Metal Plate Connected Parallel Chord Wood Trusses.

TPI (Truss Plate Institute) PCT-85 - Design Specification for Metal Plate Connected Wood Trusses.

TPI (Truss Plate Institute) TPI-85 Addendum, Appendix P (QST) - Quality Standard for Metal Plate Connected Wood Trusses.

UL (Underwriters Laboratories, Inc.) - Fire Resistance Index.

WCLIB (West Coast Lumber Inspection Bureau) - Grading Rules.

WWPA (Western Wood Products Association) - Grading Rules.

DESIGN REQUIREMENTS

Design Floor Live [and Dead] Load: [____] lbs/sq ft ([____] Kpa) with deflection limited to [1/360.] [____.]

Design Roof Live [and Dead] Load: [_____] lbs/sq ft ([_____] Kpa) with deflection limited to [1/240.] [_____.]

Provide [[____] inch ([____] mm)] camber in design of [floor] [flat roof] [________] trusses.

Minimum Truss Depth To Accommodate Mechanical Ducts: [____] inch ([____] mm).

PERFORMANCE REQUIREMENTS

Fire Resistance Rating: [Roof] [Floor] assembly rating of [________] in accordance with [ULI Design No. [____].] [____.]

SUBMITTALS

Submit under provisions of Section [01300.] [________.]

Shop Drawings: Indicate framing system, sizes and spacing of trusses, loads and truss cambers, and [________]. [Submit design calculations.]

Indicate species and wood grades, component profiles, bearing and anchor details, bridging and bracing, framed openings, drilled holes, fasteners, connectors, erection details and sequence, and field splices.

Indicate welded connections using standard AWS D1.1 welding symbols. Indicate net weld lengths.

Product Data: Provide data on proprietary connection devices [and on wood preservative materials].

QUALITY ASSURANCE

Perform Work in accordance with the following:

Lumber Grading Agency: [Certified by ALSC.] [NLGA.]

Truss Design, Fabrication, and Installation: In accordance with Truss Plate Institute BWT-76, HET-80, PCT-80 including Supplement, TPI-85 including Supplement, TSP-85 (QST).

Maintain [one copy] [[____] copies] of [each] document on site.

QUALIFICATIONS

Fabricator: Company specializing in performing the work of this section [certified by TPI] [with minimum [__________] years [documented] experience.] [approved by manufacturer.]

Design trusses under direct supervision of a Professional Structural Engineer experienced in design of this Work and licensed [at the place where the Project is located] [in the State of [____________]].

REGULATORY REQUIREMENTS

Conform to [applicable] [__________] code for loads, seismic zoning, other governing load criteria [, and fire retardant criteria].

DELIVERY, STORAGE, AND HANDLING

Deliver, store, protect, and handle products to site under provisions of Section [01600.] [________.]

Handle and install trusses in accordance with TPI HET-80.

Store trusses in vertical position resting on bearing points and braced to prevent damage.

FIELD MEASUREMENTS

Verify that field measurements are as [indicated [on shop drawings].] [instructed by the manufacturer.]

COORDINATION

Coordinate work under provisions of Section [01039.] [________.]

Coordinate the work with placement of [bearing] [support] items.

PART	PRODUCTS

FABRICATORS

[__________________________________] Product [_________].

[__________________________________] Product [_________].

[__________________________________] Product [_________].

Substitutions: Under provisions of Section [01600.] [________.]

LUMBER MATERIALS

Lumber Grading Rules: [NLGA.] [RIS.] [SPIB.] [WCLIB.] [WWPA.] [________.]

Lumber: Stress Group [____] [[________] species]; maximum moisture content of [19] [____] percent and minimum moisture content of [12] [____] percent.

****** [OR] ******

Lumber: [________] species, [________] grade; maximum moisture content of [19] [____] percent and minimum moisture content of [12] [____] percent.

Wood [Blocking] [Plating] [Opening Framing]: [In accordance with Section [06112.] [06114.] [_____.]] [Softwood lumber, [__________] species, [construction] [__________] grade, maximum moisture content of [19] [_____] percent.]

CONNECTOR MATERIALS

Steel Connectors: [ASTM A36, [Weldable Quality]] [ASTM A47, Grade [35018] [________], Group [A1] [E1] [G1] castings]; [galvanized in accordance with ASTM A123] [primed finish] [unfinished]; [____] inch ([____] mm) thick.

****** [OR] ******

Steel Connector Plates: [ASTM A446, Grade [A] [B], galvanized] [ASTM A167 Type 304 stainless steel]; [____] inch ([____] mm) thick.

Steel Split Rings: [ASTM A36] [Malleable iron], [galvanized in accordance with ASTM A123] [primed finish] [unfinished]; [____] inch ([____] mm) thick.

****** [OR] ******

Steel Split Rings: [ASTM A167 Type 304 stainless steel]; [____] inch ([____] mm) thick.

Truss Bridging: [Type, size and spacing recommended by truss manufacturer.] [________.]

Bearing Plates: [Electro-galvanized] [Hot dip galvanized] [unfinished] [________] steel.

Bolts, Nuts, and Washers: Medium carbon steel, [electro-galvanized] [hot dip galvanized] [unfinished] [________]; size and type to suit application.

Bearing Plate Anchors: [Expansion shield type for anchorage to masonry or concrete.] [Bolts for anchorages to steel.] [________.]

Metal Primer: [Galvanize] [________] type.

WOOD TREATMENT

Fire Retardant: [AWPA Treatment C20, [Exterior] [Interior] Type,] chemically treated and pressure impregnated; capable of providing a maximum flame spread/smoke development rating of [____] / [____]; [________] manufactured by [____________].

Wood Preservative (Pressure Treatment): [AWPA Treatment C2] using [water borne] [_____________] preservative with [0.25] [_____] percent retainage.

Wood Preservative (Surface Application): [Clear] [colored], [_____________] type, [________] manufactured by [____________].

FABRICATION

Fabricate components in accordance with [AITC] [TPI] [________], with joints neatly fitted.

Surface Texture of Timber: [Rough sawn] [Resawn with fine band saw] [smooth surface] [________]; on [four] [the exposed three] [_____] sides.

Cut members to accurate length to achieve [tight] [accurately spaced] joint connections.

Trial fit members during fabrication to assure accurate configuration and fit.

SHOP FINISHING

Connectors: Prime except where cast in concrete or in contact with cementitious materials.

PART	EXECUTION

EXAMINATION

Verify site conditions under provisions of Section [01039.] [________.]

Verify that supports and openings are ready to receive trusses.

Verify sufficient bearing surface area.

ERECTION

Install trusses [in accordance with manufacturer's instructions.] [as indicated.] [at a spacing of [____] ft ([____] m) oc.]

Place trusses level and plumb, in correct position.

Make provisions for erection loads, and for sufficient temporary bracing to maintain structure plumb, and in true alignment until completion of erection and installation of permanent bracing.

Do not field cut or alter structural members without approval of Architect/Engineer.

Brace wood trusses in accordance with TPI BWT-76.

Place permanent bridging, bracing, and anchors.

Place headers and supports to frame openings required.

Frame openings between trusses with lumber [in accordance with Section [06114.] [________.]

Coordinate placement of [decking] [sheathing] with work of this section.

After erection, touch up [primed] [galvanized] surfaces with [primer consistent with shop coat.] [specified primer.]

SITE APPLIED WOOD TREATMENT

Apply preservative treatment in accordance with manufacturer's instructions.

Brush apply [one] [two] coats of preservative treatment on wood in contact with [cementitious materials] [roofing and related metal flashings] [and] [_________]. [Treat site-sawn cuts.]

Allow preservative to dry prior to erecting members.

TOLERANCES

Framing Members: [1/4] [_____] inch ([6] [_____] mm) maximum from true position.

Maximum Gap in Tension Member Joints: [1/16] [_____] inch ([1.5] [_____] mm).

Maximum Gap in Compression Member Joints: [1/32] [_____] inch ([0.8] [_____] mm).

END OF SECTION