Guys, think what you want, but do not be fooled by that statement on incisive perforations to obtain the .40 retention for Pressure treatment.
Be aware that all treated wood is not created equal. Most wood species do not readily accept chemical preservatives, and must first be “incised” or perforated with a series of small slits along the grain of the wood’s surface. Incising allows sufficient penetration of the preservative to meet American Wood Preserver’s Association (AWPA) Standards. Southern Pine is one of the few wood species that does not require incising.
Species and Products
Borates are used as a pressure treatment to preserve the following species per AWPA Standards:
• Lumber (without incising): Southern pine & ponderosa pine.
• Lumber (with incising): Coastal Douglas-fir, hem-fir and western SPF.
• Plywood: Southern pine and Douglas-fir.
Trees / logs from which commercial wood is cut have a number of different layers. The two primary layers are called heartwood and sapwood. Heartwood provides most of the “structural” strength to the living tree while the sapwood transports the sap from the base of the tree up to the leaves.
Wood preservatives penetrate sapwood easier than heartwood. As a result, wood species such as Southern Pine, which have a high percentage of sapwood, are predominately used in pressure treating.
Wood species such as Douglas Fir have more heartwood so modifications are typically required to the preservative to achieve adequate penetration and retention levels. The modification that is usually made is to change the “carrier” used in the preservatives. Often this carrier uses an ammonia base, which improves the penetration but also tends to increase the corrosivity of the preservative. (The carrier used to treat sapwood species usually has an amine base.) This increase in corrosivity may be short term or long term. Hybrid carriers, a mix of amine and ammonia bases, may also be used to treat heartwood species. Incising (perforating the wood with small slits) may also be utilized to increase the penetration of preservative in heartwood species.
Borate treated wood products can only be used for above ground interior or weather protected exterior applications. There are two retention levels. Each level is measured on the basis of either the boric oxide or disodium octaborate tetrahydrate (DOT).
• 0.17 pcf (B2O3)/0.25 pcf (DOT)
• 0.28 pcf (B2O3)/0.42 pcf (DOT) *
- This higher retention is effective against the Formosan termite (Coptotermes formosanus).
ACQ can be used for any construction project and is particularly suited for applications such as decking, playgrounds, walkways, benches, outdoor tables and chairs, fencing, gazebos and landscaping, where long-term protection against decay and termites is a priority.
Hope this helps to clarify.