SECTION 06135

HEAVY TIMBER TRUSSES

PART 1 GENERAL

SECTION INCLUDES

Heavy structural timber for truss framing.

Bridging, bracing, and anchorage.

Connection hardware.

PRODUCTS FURNISHED BUT NOT INSTALLED UNDER THIS SECTION

Section [03001 - Concrete Work:] [03100 - Concrete Formwork:] Steel support fabrications to be cast in concrete.

Section [_____ - __________:] Steel support fabrications [embedded] [bearing upon and anchored] into masonry.

RELATED SECTIONS

Section [_____ - __________:] Load bearing supports.

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

Section 06114 - Wood Blocking and Curbing.

Section 06125 - Wood Decking.

Section 06130 - Heavy Timber Framing.

Section 06181 - Glue-Laminated Structural Units.

Section 06192 - Prefabricated Wood Trusses.

Section 06196 - Plywood Web Joists.

Section 09900 - Painting: [Painting.] [Staining and finishing.]

REFERENCES

AITC - American Institute of Timber Construction.

ALSC - American Lumber Standards Committee: Softwood Lumber Standards.

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

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

ANSI/AWS D1.1 - Structural Welding Code.

ASTM A36 - Structural Steel.

ASTM A47 - Malleable Iron Castings.

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

AWPA - American Wood Preservers' Association.

FS TT-W-571 - Wood Preservation: Treating Practices.

NFPA - National Forest Products Association.

RIS - Redwood Inspection Service: Standard Specifications for Grades of California Redwood Lumber.

SFPA - Southern Forest Products Association.

TPI - Truss Plate Institute.

UL - Underwriters' Laboratories.

WCLIB - West Coast Lumber Inspection Bureau: Standard Grading Rules for West Coast Lumber.

WWPA - Western Wood Products Association.

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.] [_____.]

Fire Resistance Rating: [Roof] [Floor] assembly rating of [_____] in accordance with [UL.] [_____.]

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

QUALITY ASSURANCE

Lumber Grading Agency: Certified by ALSC.

Truss Plates: In accordance with Truss Plate Institute (TPI) requirements.

QUALIFICATIONS

Fabricator: Company specializing in fabrication of timber trusses [certified by AITC] with [three] [_____] years minimum [documented] experience.

Design trusses under direct supervision of Professional Structural Engineer experienced in design of this work registered in the State of [_______________.]

REGULATORY REQUIREMENTS

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

Conform to [applicable] code for [fire retardant] [__________] requirements.

Conform to [UL] [_____] requirements to achieve rating indicated.

SUBMITTALS

Submit shop drawings under provisions of Section [01300.] [01340.]

Submit shop drawings indicating framing system, sizes and spacing of trusses, loads and truss cambers, bearing and anchor details, bridging and bracing, framed openings, and [__________.] [Submit design calculations.]

Indicate dimensions, wood grades, components profiles, drilled holes, fasteners, connectors, erection details and sequence, and field splices.

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

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 [_______________.]]

[Submit product data on proprietary connection devices.]

[Provide technical data on wood preservative materials.]

DELIVERY, STORAGE, AND HANDLING

Deliver products to site under provisions of Seciton [01600.] [01610.]

Store and protect products under provisions of Section [01600.] [01620.]

Transport and store trusses in accordance with fabricators' instructions.

Protect trusses from moisture, warpage, and distortion

during transit and when stored.

PART 2 PRODUCTS

FABRICATORS

[____________________________________________.]

[____________________________________________.]

[____________________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

LUMBER MATERIALS

Lumber Grading Rules: [NFPA.] [RIS.] [SFPA.] [WCLIB.] [WWPA.]

Lumber: Stress group [_____;] [__________] species; [__________] grade; maximum moisture content of [19] [_____] percent and minimum moisture content of [12] [_____] percent.

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

CONNECTION MATERIALS

Steel Connectors: [ANSI/ASTM A446 steel, Grade [A;] [B;]] [ASTM A36, [weldable quality;]] [ASTM A47, Grade 35018, Group [A1] [E1] [G1] castings;] [galvanized] [primed] finish; [_____] inch ([_____] mm) thick.

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

Steel Connectors: ASTM A167, Type 304 stainless steel.

Bolts, Nuts, and Washers: Medium carbon steel; [plain finish;] [galvanized coating;] [__________;] size and type to suit application.

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

Zinc [Chromate] [Rich] Primer: [____________________.]

WOOD TREATMENT

Fire Retardant: Chemically treated and pressure impregnated; capable of providing a maximum flame spread/fuel contribution/smoke development rating of [_____/_____/_____;] [_______________] manufactured by [____________________.]

Wood Preservative (Pressure Treatment): [FS TT-W-571] [AWPA Treatment C2] using [water borne] [__________] preservative with [0.30] [_____] percent retainage.

FABRICATION

Verify dimensions and site conditions prior to fabrication.

Fabricate components in accordance with [AITC,] [_____,] with joints neatly fitted, [welded,] and ground smooth.

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 joint connections.

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

SHOP/FACTORY FINISHING

Prime connectors, except where cast in concrete or in contact with cementitious materials.

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

Galvanize connectors in accordance with ANSI/ASTM A123.

TOLERANCES

Connector Locations: Within [1/8] [_____] inch ([3] [_____] mm) of true position.

Length: Within [1/16] [_____] inch ([1.5] [_____] mm) of required length.

End cut: Flat and true with member length to assure consistent load transfer.

PART 3 EXECUTION

EXAMINATION

Verify that supports and openings are ready to receive trusses and field measurements are as [shown on shop drawings.] [instructed by the fabricator.]

Verify sufficient end bearing area.

Beginning of installation means acceptance of [existing

surfaces.] [substrate.]

PREPARATION

Coordinate placement of [bearing] [support] items.

INSTALLATION

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

Place trusses true to line and level, in correct position.

Make provision for erection loads and provide temporary bracing to maintain structure safe, plumb, and in true alignment until completion of erection.

Place permanent bridging, bracing, and anchors.

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

Place headers and supports to frame openings required.

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

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

TOLERANCES

Framing Members: [1/2] [_____] inch ([13] [_____] mm) per 12 feet (3.5 m) 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