SECTION 718 - TIMBER AND DIMENSION LUMBER
718.01 Timber and Dimension Lumber . General . All timber and dimension lumber
shall be Southern pine and shall conform in all respects to applicable requirements of AASHTO M 168. Inspection for conformance to these specifications will be conducted in accordance with Department SOP. Timber and dimension lumber shall be furnished in the sizes shown on the plans or as specified. Unless otherwise specified, timber and dimension lumber shall be No. 1, or better, graded according to the late st American Lumber Standards. Only one type of preservative shall be used fo r the treatment of materials for any one class of construction on a project, unless otherwise specified. Where timber and dimensional lumber is to be used in non-highway construction or use, such as decking, handrails in walking trails, or in any manner where general public exposure by touch is possible, the treatment requirements will be as per project plans and/or approved by the State Materials Engineer.
718.02 Untreated Timber and Dimension Lumber . Untreated timber and dimension
lumber shall comply with the requirements set out in Subsection 718.01.
718.03 Treated Timber and Dimension Lumber . Timber and dimension lumber to be
treated shall meet the requirements herein sp ecified and shall be treated by a pressure method to the minimum required retainage of preservative as specified on the plans or elsewhere in the specifications. Treated timbe r or dimensional lumber will not be accepted for use unless it has been inspected by an auth orized representative of the Department and found to be satisfactory both before and after treatment. Inspection prior to treatment may be waived by the Testing Engineer when the preservative will be pentachlorophenol or chromated copper arsenate.
718.03.1 Seasoning . Seasoning timber, dimension lumber, piles and poles to be treated
with preservatives shall conform to the requirements of AWPA.
718.03.2 Treatment.
718.03.2 1--General . Insofar as practicable, each charge shall consist of pieces
approximately equal in size, moisture, and sapwood content into which approximately equal quantities of preservative can be injected. Each layer of material shall be separated at each end, and at the center when necessary, by strips at least 3/8 inch in thickness. Caps, stringers, and other large timbers shall be separated by strips of at least 1/2-inch thickness. All timber and lumber shall be treated in accordance with AWPA treating practices unless otherwise specified herein. Unless otherwise directed, the type and minimum quantity of preservative shall be in accordance with TABLES 1, 2 or 3. Any treated timber or lumber to be painted shall be treated in accordance with Subsection
718.04 3, Type B solvent, or Subsection 718.04.4.
Brackish water, as listed in TA BLES l, 2 or 3, shall mean salt waters, bordering land, and waters adjacent thereto that are subject to tidal flow.
718.03.2 2--Penetration . Unless otherwise specified, treated timber and lumber shall
show a 100 percent sapwood penetration or a minimum penetration of four inches. The test method for determining the amount of preservative retained will be either as specified in AWPA or Mississippi Test Methods. The borer cores shall be obtained in accordance with AWPA Standard M2 and shall be taken from pieces having a sapwood depth at least equal to the sampling zone specified as follows:
a.Round Units, piling and poles, shall be in accordance with AWPA requirements.
b.Structural members less than four inches shall be from zero to one and one half inches from the surface.
c.All other structural members shall be from zero to two inches from the surface.
718.03.2 3--Inspection. The Department shall be notified sufficiently in advance of
treating the material so that an inspector may be furnished at the plant to inspect the material and the treatment of same. All ma terials and processes used in the manufacture of the material shall be subject to inspection. The plant shall be equipped with the necessary gauges, thermometers, appliances, and facilities to enable the inspector to determine the conditions at all stages of the treatment and to satisfy the inspector that the requirements of the specificati ons are fulfilled. The manufacturer shall also provide the apparatus and chemicals necessary for making tests at the plant as required by the Department. All equipment, apparatus, etc., shall be maintained in proper and satisfactory condition for use at all times. Tests for penetration of preservative shall be made with an increment borer. Test holes shall be plugged with treated plugs. All borings shall be taken at the center of the narrow side of the piece. Sufficient borings shall be taken to ensure that the specified penetration has been obtained, with a minimum of 20 borings required for each charge of materials. If 20% or more of the borings from a charge of treated material fail to meet the penetration requirements, the entire charge shall be rejected and subject to retreatment. If upon retreatment, the material meets the penetratio n requirements, it will be accepted. Only one retreatment will be permitted, and any apparent damage due to retreatment shall be cause for rejection.
718.03.3 Handling Treated Material . Any bruising or rough handling will be cause for
rejection.
718.03.4 Storage of Treated Material . All material treated for stock shall be stacked as
compactly as possible on a well-drained surface. Material shall be supported on sills spaced as necessary, not to exceed 10 foot intervals and shall have at least one foot of air space beneath the stacks. All materials treated with CCA for use in bu ildings and applications where painting is required shall be dried after treatment. The treated wood shall be kiln dried by American Lumber Standards, or air dried for a period of at least 21 days before shipment.
718.04 Preservative . The preservatives shall meet the applicable requirements of
AWPA, and the water content in an oil preservative shall not exceed 3.0% unless otherwise approved by the Engineer; but in no case shall it exceed 5.0%.
718.04.1 Blank.
718.04.2 Blank.
718.04.3 Pentachlorophenol . The pentachlorophenol sha ll meet the requirements of
AWPA P-8. The test methods shall be e ither AWPA or Mississippi Test Methods. The hydrocarbon solvent used in the pentachlorophenol solution shall meet the requirements of AWPA P-9, Type A or B. Wh en painting is required, Type B solvent shall be used. Type A solvent shall be used for all other treatment unless otherwise specified. Minimum Treatment Rates for Pe ntachlorophenol Preservative Material Coastal Areas and Br ackish Water Other Locations Retention pounds / cubic foot Retention pounds / cubic foot Lumber Piling Poles Material to be Painted (1) Penta Not Permitted 0.60
2.0.80 0.80 0.60 (2) Notes: (1) Pentachlorophenol not permitted for lumber that will be in contact with brackish water. Lumber in the Coasta l Area that is not in contact with brackish water may be treated as specified for "Other Locations".
2.Treated at the rate specified ab ove using AWPA P-9, Type B Solvent.
718.04.4 Chromated Copper Arsenate (CCA) . The solution shall contain a sufficient
concentration of the water-born preservative to produce the minimum specified retention. The preservative shall meet the requirements of AWPA P-5, CCA Type B or C. The test methods shall be either AWPA or Mississippi Test Methods. Minimum Treatment Rate For Chromated Copper Arsenate Preservative Material Coastal Areas and Brackish Water Other Locations Retention pounds / cubic foot Retention pounds / cubic foot Lumber (1) Piling Poles 2.50 2.50 0.60 0.80 0.80 0.60 Notes: (1) Lumber in the Coastal Area that is not in contact with brackish water may be treated as specified for "Other Locations". SECTION 719 - PILES
719.01 General . Piles shall be untreated timber, treated timber, precast concrete, cast-in-
Source: Mississippi Standard Specifications for Road and Bridge Construction, 2017 Edition. Pages 851–852 of 1,113.