The old treated lumber used an Arsenic-based preservative solution, and was known as CCA treated lumber (chromated copper arsenate). The new chemical formula is known as ACQ treated lumber (Alkaline Copper Quaternary).
It is important to understand that the corrosive nature of ACQ treated lumber comes from electrolysis, not a low PH(acid) quality of the lumber. One of the easiest ways to use a non ACQ rated metal component is simply to insulate it from the copper in the treated lumber with an adhesive flashing barrier.
Pressure-treated lumber is the most economical choice, but the new formulas are highly corrosive to metal fasteners. Learn how to choose materials and fasteners.
Deck Plus carriage bolts have a exterior duplex coating that is 2X more corrosion resistant than galvanized fasteners and is recommended for use with treated lumber Intended for use with wood deck and fence construction Carriage bolts should be used with nuts and washers of the same diameter ...
is recommended for use with pressure-treated lumber.. Type 304 or 316 stainless steel fasteners and connectors, commonly used in severe exterior exposures, provide maximum corrosion resistance.
10) Pressure treated lumber is resistant to attack by termites and carpenter ants. This assumption is half true. Entomological studies have shown that arsenical treatments like the CCA commonly used in pressure treated lumber does repel and can kill termites.
Fasteners treated with a durable ACQ corrosion-resistant proprietary coating have more of a safety factor than standard coated carbon steel fasteners. However, all these factors make the fasteners more costly than the fasteners used in CCA-treated wood.
Most rot-resistant pressure-treated lumber sold for homeowner use relies on two copper-based wood preservatives -- alkaline copper quaternary and copper azole -- in place of the arsenic-based compounds formerly used.
It is a well known fact that the newer ACQ or AC2 pressure treated lumber will corrode the average galvanized deck nail and hangers. My question is, is this corrosion a problem when builders are nailing the pressure treated sill to the wall framing (like on a slab on grade foundation).
Our White Vinyl Roll Flashing is made of exterior-grade polyvinyl chloride for use with all pressure-treated lumber. Nail the flashing onto the house. Z Flashing tucks under the siding and wraps over the top of the ledger board.
Many pressure-treated lumber manufacturers recommend using only stainless steel or hot-dipped galvanized nails, screws, bolts, anchors, and connectors when working with the material.
Pressure treated lumber products, such as YellaWood ? brand products, are treated in a pressurized cylinder. The treatment process forces a waterborne preservative deep into the cellular structure of the wood providing long-term protection against rot, fungal decay and termite attack.
Glenn Mathewson, a former deck builder who is now a building inspector in Westminster, Colo., tells a story of a builder who used lumber treated with a micronized-copper preservative. Micronized copper uses a less soluble form of the metal that isn’t supposed to leach out of the wood, and is therefore said to be less corrosive.
(Steel Deck Products in Contact with Pressure Treated Lumber, Steel Deck Institute Position Statement, August 2006.) As a result, SDI recommends a barrier of water and ice shield or equivalent be used between pressure-treated lumber and steel deck products or accessories.
Pressure-treated lumber, also known as Alkaline Copper Quaternary (ACQ) lumber, is wood that is chemically treated to make it more resistant to rotting, and to repel insects. The wood is placed into pressurized tanks where chemicals are forced deep into the fibers of the lumber.
The ink used for marking pressure-treated lumber grades (applied at the lumber mill, not a UFP pressure treating plant) is a water-based ink that will naturally disappear over time from weather and foot traffic.