Quantcast Exposure Of Untreated Wood

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5.3.5 Standards.  The American Wood Preservers' Association produces consensus stand-
ards for the pressure treatment of wood with preservatives in the United States. A list of the stand-
ards is shown in Appendix A. The corresponding Government Services Administration (GSA)
specification on processes for m-depth preservative treatment of wood is TT-W-571, Wood Preserva-
tion: Treating Practices (Appendix B), which is used in procurement through DLA/DCSC. Reten-
tion requirements of these standards are summarized in Table 5-1.
These standards and specifications spell out details regarding treatment of different commodities
such as lumber, poles, piles, crossties, etc.; choice of preservatives; methods for analysis of preserv-
atives; penetration and retention; and other critical aspects of the pressure treating of wood with pre-
servatives. Therefore, they provide both producer and consumer with state of the art information
and a common reference point when specifying treated wood material and checking quality.
5.4 CARE AND HANDLING OF TREATED WOOD. In addition to the proper selection of
materials and treatment methods, certain precautions must be taken with treated wood products if
the expected service life is to be achieved. They are:
5.4.1 Exposure Of Untreated Wood.  All cutting, boring and other machining of wood
should be done prior to preservative treatment as much as possible. Cutting treated wood at the con-
struction site exposes untreated heartwood to wood destroying organisms. Examples might include
the cutting off of piling tops, boring of heavy timbers, etc.
Untreated wood, exposed by cutting, etc., at the job site should be field treated. The same wood pre-
servatives used to pressure treat commodities can often be used for treatment of field cuts or else a
copper naphthenate solution containing a minimum of two percent copper metal can be used. For
detailed information on preservatives and field application methodology, refer to AWPA M4 which
includes all treated wood products.
5.4.2 Handling And Storage.  Poles and piling treated with oil borne preservatives should
be installed soon after treating to minimize lateral movement of preservative to the extent that sub-
sequent durability of the treated product will be reduced. This is a particularly important considera-
tion in procurement programs for poles that might normally be expected to be in transit or in storage
for a minimum of one year.
Poles and piles treated with creosote or oil based preservatives stored in a horizontal position for
over 18 months can lose preservative due to bleeding and volitization or the preservative can
migrate in the wood. To minimize this loss, poles and piling should be rotated periodically while in
Migration or loss of preservative during storage is not a problem with water-borne preservatives.


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