812.01 DESCRIPTION. Furnish and install lumber, timber, and hardware.
Treat all timber unless otherwise specified.
812.02 MATERIALS. Materials shall comply with the following subsections:
Castings 1013.05, 1013.06 Structural Timber and Lumber 1014.01 Timber Preservatives 1014.03 Treatment 1014.04 Connectors 1014.05 Hardware and Structural Shapes 1014.06 Roofing Pitch 1018.09
812.03 Species of Wood.
812.03.1 Permanent Structures: Use Douglas Fir or Southern Yellow
Pine for permanent structures unless otherwise specified in the plans. Similar components must be of the same species throughout each structure.
812.03.2 Temporary Structures: Temporary bridges shall conform to
Section 817, “Temporary Works.” All other temporary structures may be any satisfactory species and grade of timber.
812.04 STORAGE OF MATERIAL. Keep lumber and timber stored on the site
in orderly stacks. Stack material on supports above ground to permit free circulation of air between tiers and courses. Store timber in a manner which will prevent changes in dimensions, twisting, warping, and splitting of members before assembly. Provide protection from the weather by suitable covering.
812.05 TIMBER. When treated timber is damaged or cut, repair disturbed areas
with timber preservatives conforming to 1014.03.
812.05.1 Workmanship: Drive nails and spikes with just sufficient force to
set the heads flush with the surface of the wood. Deep hammer marks in wood surfaces shall be considered evidence of poor workmanship and cause for rejection.
812.05.2 Surfacing: Lumber and timber, except bulkhead planks and sway
bracing, shall be S4S (Surfaced Four Sides).
812.05.3 Handling: Handle treated timber with rope slings, without
dropping or breaking of outer fibers, bruising, or penetrating the surface with tools.
812.05.4 Framing and Boring: Cut, frame, and bore treated timber before
treatment insofar as practical. When treated timber is to be placed in water infested by marine borers; avoid untreated cuts, borings, or other joint framings below high water elevation.
812.05.5 Installation of Timber Connectors: Install the split ring and
the shear plate in precut grooves of dimensions as specified or as recommended by the manufacturer. Force the toothed ring and the spike grid into contact surfaces of the timbers joined by means of pressure equipment. Embed connectors of this type at a joint simultaneously and uniformly.
812.05.6 Cuts and Abrasions: After carefully trimming, cover cuts and
abrasions in treated piles or timbers, with two applications of preservative and cover with hot roofing pitch. Repair cuts and abrasions in timber treated with other preservatives with the same preservative.
812.05.7 Bolt Holes: Treat holes bored in pressure-treated material with
preservative. Treat unused bore holes and spike holes with preservatives and plug with tight-fitting treated plug.
812.05.8 Temporary Attachment: Fill holes from temporary attachments
with galvanized nails or spikes, or plug as required for bolt holes.
812.06 Treatment of Pile Heads.
812.06.1 General: After cutting, treat pile heads to prevent decay. Pile
heads to be encased in concrete will not require treatment. Immediately after making final cut -off on treated timber foundation piles, give the cut area two liberal applications of preservative followed by a heavy application of hot roofing pitch acceptable to the engineer, or other approved sealer. Protect heads of treated timber piles in bents or where the cut-off is exposed as follows. Thoroughly brush coat the sawed surface with two applications of preservative, then place two layers of heavy canvas, size 20 inch x 20 inch, saturated with hot roofing pitch, follo wed by a 24 inch x 24 inch, 28 gauge galvanized metal cover. Bend the cover down over the pile approximately 45 degrees.
812.07 Holes for Bolts, Dowels, Rods and Lag Screws.
Bore holes for drift bolts and dowels perpendicular to the face of the timber 1/16 inch less in diameter than bolt or dowel. For square drift bolts or dowels, the diameter of the bored hole shall be equal to the least dimension of the bolt or dowel. Bore holes for machine bolts the same diameter as the bolt. Bore holes for rods 1/16 inch greater in diameter than the rod. Bore holes for lag screws not larger than the body of the screw at the base of the thread.
812.08 BOLTS AND WASHERS. Use a washer of the size and type specified
under bolt heads and nuts which would otherwise come in contact with wood. Stacked washers will not be permitted. Bolts shall not project more than 1 inch beyond the nut on work securely tightened. Saw cut long bolts or clip, grind smooth, and repair as specified in 811.08. Nuts of bolts shall be locked after they have been tightened. Tack welding will not be allowed.
812.09 COUNTERSINKING. Countersink when required to prevent fasteners
from protruding beyond the face of the timbers. Paint horizontal recesses formed for countersinking with a preservative prior to hardware installation. After hardware is in place, fill with hot roofing pitch.
812.10 FRAMING. Accurately cut and frame lumber and timber to a close fit so
that joints will have even bearing over the contact surfaces. No shimming will be permitted in making joints nor will open joints be accepted. Tightly bind or clamp mating pieces in position prior to drilling bolt holes.
812.11 PILE BENTS. Drive piles in accordance with Section 804.
812.12 CAPS. Place timber caps in a manner to secure uniform bearing over
tops of supporting posts or piles. Secure caps by drift-bolts of at least 3/4 inch diameter extending at least 9 inches into posts or piles. Place drift-bolts approximately in center of the post or pile.
812.13 BRACING. Bolt ends of bracing through pile, post, or cap with a bolt of
at least 5/8 inch diameter. Intermediate intersections of bracing shall be connected with wire or bolts.
812.14 STRINGERS. Size stringers at bearings and position stringers so that
knots near edges will be near the top. Outside stringers may have butt joints with ends cut on a taper, but lap interior stringers to take bearing over the full width of floor beam or cap at each end. When stringers are two panels in length, stagger the joints. Neatly and accurately frame cross-bridging between stringers and securely toe-nail with at least two nails in each end. Provide cross-bridging members with full bearing at each end against sides of stringers. Place cross-bridging at the center of each span.
812.15 PLANK FLOORS. Single plank floors consist of a single thickness of
plank supported by stringers or joists. Lay planks heart side down, with 1/4 inch openings between them for seasoned material and with tight joints for unseasoned material. Securely spike each plank to each joist. Grade planks as to thickness and lay so that no two adjacent planks vary in thickness by more than 1/16 inch. Two-ply timber floors consist of two layers of flooring supported on stringers or joists. Pressure treat the lower course with a preservative. Lay the top course either diagonal or parallel to the centerline of roadway, as specified, and securely fasten each floor piece to the lower course. Stagger joints at least 3 feet. If placing the top course parallel to the roadway centerline, take care to securely fasten ends of flooring. At each end of the bridge, bevel these members.
812.16 LAMINATED OR STRIP FLOORS. Place strips on edge at right
angles to the roadway centerline. Spike each strip to the preceding strip at each end at approximately 18-inch intervals. Drive the spikes alternately near the top and bottom edges. Spikes shall be of sufficient length to pass through two strips and at least halfway through the third strip. If using timber supports, toe-nail every other strip to every other support. When specified, securely attach strips to steel supports with approved galvanized metal clips. Take care to have each strip vertical and tight against the preceding one and bearing evenly on supports.
812.17 WHEEL GUARDS AND RAILING. Frame wheel guards and railing in
accordance with the plans and erect true to line and grade. Lay wheel guards in sections at least 12 feet long.
812.18 PAINTING AND PROTECTIVE COVERINGS. Paint parts of
structures as specified. Paint metal parts not galvanized in accordance with Section 811. When timber decks are provided, protect top flanges of stringers and floor beams by a covering composed of a heavy layer of hot roofing pitch and one thickness of two-ply tar paper wide enough to project 3 inches beyond edges of members. Bend these edges down approximately 45 degrees.
812.19 MEASUREMENT. Quantities will be the design quantities measured by
the number of thousand board feet, (MBFM). Hardware will not be measured for payment, unless specified on the plans as Structural Metalwork and a contract pay item provided.
812.20 PAYMENT. Payment for timber will be made at the contract unit price
per thousand board feet. Payment will be made under: Item No. Pay Item Pay Unit 812-01 Treated Timber (Type) MFBM
Treated Timber in other states
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