ProWood® Micro and ProWood Micro CA Pressure-Treated Lumber FAQ
Lumber’s greatest enemy is biological attack—destruction by termites, fungi, marine borers and bacteria. After more than a half century of scientific tests and practical experience with various treating chemicals, there is a variety of weapons that have been formulated to protect wood against insects, rot and decay.
Why use pressure-treated lumber?
What preservatives are used for pressure treatment and how long are they effective?
What ingredients make up ProWood Micro and ProWood Micro CA?
How does ProWood Micro and ProWood Micro CA differ from ACQ?
Is special handling required?
How safe is treated wood?
Can preserved wood be used indoors?
Why can I use pressure-treated wood for a picnic table and not a countertop?
Can treated wood be used in gardening?
What is the significance of the tags stapled to my lumber?
Are there different types of treated wood for different uses?
Any fastener recommendations when building with ProWood Micro and ProWood Micro CA?
I cut the end off of my pressure-treated wood, and it looks like it isn’t treated in the middle. Do I have a bad piece of treated wood?
Is it safe to use pressure treated lumber for animal enclosures such as a bird feeder or fish pond retaining wall? I have heard that leaching may be a problem.
After my project is built, is any special maintenance necessary?
What else should I know about treated wood?
Why use pressure-treated lumber?
Lumber’s greatest enemy is biological attack—destruction by termites, fungi, marine borers and bacteria. After more than a half century of scientific tests and practical experience with various treating chemicals, there are a variety of weapons that have been formulated to protect wood against insects, rot and decay.
What preservatives are used for pressure treatment and how long are they effective?
For a long time, CCA (Chromated Copper Arsenate) has been used as a reliable wood preservative. CCA-treated wood protects against all major forms of destructive attack and is effective for many years. More recently, preservative manufacturers made a transition to a newer preservative, ACQ (Alkaline Copper Quaternary). ACQ is also effective for decades, reducing demands on forest resources. The next generation of preserved wood is ProWood Micro and ProWood Micro CA, a revolutionary product being offered throughout the United States by Universal Forest Products.
What ingredients make up Pro Wood Micro and ProWood Micro CA?
ProWood Micro and ProWood Micro CA are waterborne systems that are copper based. Together, the compounds of copper and quaternary (for MCQ) or copper and azole (for CA) provide protection from a broad spectrum of fungi and termites, preventing rot and decay. Laboratory and field studies have proven that micronized copper products provide protection against fungal decay and termites in both above ground and ground contact applications.
How does ProWood Micro and ProWood Micro CA differ from ACQ?
ProWood Micro and ProWood Micro CA use “micronized” copper particles that bond permanently to wood cells. ProWood Micro and ProWood Micro CA cause less corrosion in fasteners and gives wood a lighter, fresher appearance after treatment than ACQ.
Is special handling required?
Our Safe Handling Information Sheets outline specific handling tips.
The single most important precaution is DO NOT BURN TREATED WOOD. Burning treated wood releases the chemical bond with wood cells, so dispose of scraps and sawdust with your landfill trash. Wear gloves when handling treated lumber. And always wear safety goggles and a dust mask when sawing or cutting treated lumber just as you would with untreated lumber.
How safe is treated wood?
Very safe when used as directed. The preservative injected into lumber reacts with the wood substance to form an insoluble complex. It won’t evaporate or vaporize. Treated wood is clean, odorless, non-staining, safe to work with and handle. Its locked-in protection is nonirritating to children, adults, animals and plants. The minute amounts of preservative released during a treated wood structure’s serviceable lifetime have been carefully studied. The conclusion is clear: it is safe for the environment and safe for people and pets. The process used to treat ProWood® Micro and ProWood Micro CA is the first to gain Environmentally Preferable Product (EPP) status as certified by Scientific Certification Systems (SCS). Scientific Certification Systems is a third-party certification services and standards development company. According to the EPA, to be EPP certified means that the product has a reduced impact on human health and the environment when compared to other products that serve the same purpose.
Can preserved wood be used indoors?
Treated wood may be used indoors for any application except cutting boards and countertops.
Why can I use pressure-treated wood for a picnic table and not a countertop?
Simply because picnic tables are primarily used for serving prepared food while a kitchen countertop is used primarily as a cutting surface for raw food.
Can treated wood be used in gardening?
Yes. Treated timbers used to construct raised vegetable and flowerbeds are increasingly popular and practical. Recent scientific tests prove there is no significant uptake of preservatives into plants. And treated wood used for tomato stakes, flowerbed edging, planters, retaining walls, trellises, and compost bins have the added advantage of lifetime durability.
What is the significance of the tags stapled to my lumber?
Universal Forest Products places end tags on all of its pressure-treated products to ensure that our customers know key information about the product such as the type of warranty, whether it is for use in direct ground contact or only above ground applications, and where applicable, information needed for acceptance by local building codes. Many of these tags on our treated wood products even have detailed information on the safe handling of our pressure-treated products, the same information contained in the Safe Handling Information Sheets.
Are there different types of treated wood for different uses?
Yes. Our tags will always state “above ground only” or “ground contact” so you can be sure you are using the right material for the job. Higher levels of preservative are available for special purposes such as extensive moisture/earthen contact - e.g., in foundations, pole barns, fresh & saltwater docks, culverts, etc. For more detail, refer to the End Uses for ProWood page.
Any fastener recommendations when building with ProWood Micro and ProWood Micro CA?
Use hot-dip galvanized fasteners or other fasteners as required by building codes; otherwise, your treated wood will last longer than the unprotected fasteners you've used to put it together. Since ProWood Micro and ProWood Micro CA are less corrosive than ACQ, these recommendations are the same as they were with CCA-treated lumber. Fastener manufacturers may also recommend products that work well with ProWood Micro and ProWood Micro CA. View the ProWood Micro Advantage - Fasteners page for more information.
Aluminum building products can be placed in direct contact with ProWood Micro and ProWood Micro CA treated wood products used for interior uses and above ground exterior applications such as decks, fencing, and landscaping projects. Examples of aluminum products include siding, roofing, gutters, door and window trim, flashing, nails, fasteners and other hardware connectors. Aluminum contact is not recommended when ProWood Micro and ProWood Micro CA treated wood products are immersed in water or are subject to frequent and prolonged wetting or other severe exposure conditions. In such cases, a moisture resistant protective barrier should be placed between the aluminum products and ProWood Micro and ProWood Micro CA treated wood.
I cut the end off of my pressure-treated wood, and it looks like it isn’t treated in the middle. Do I have a bad piece of treated wood?
No. Most commonly this is heartwood which is naturally decay resistant. This is doesn't indicate if the wood was properly treated, and you do not need to be concerned. With the exception of some Western species, these end cuts do not require any special treatment. Refer to the ProWood Micro Warranty (pdf - 77 KB) and ProWood Micro CA Warranty (pdf - 117 KB) for details.
Brush-on Preservatives for Field Cuts
According to American Wood-Preservers' Standard M4-06, lumber and timber which are used in above ground applications and are of sapwood species such as southern, red or ponderosa pine, generally do not require treatment to provide a good service life. This category includes the majority of the treated products Universal Forest Products provides. Other heartwood species, typically found in the Western U.S. should be field treated when cut or drilled. If you are concerned about wood exposed due to cutting or drilling, you can use a brush-applied preservative.
Home centers and lumberyards often carry brush-applied preservative systems based on two different active chemicals: either copper naphthenate or IPBC (3-iodo 2-propynyl butyl carbamate). These systems should be applied, in accordance with their labels, to any surface exposed by damage or field fabrication. Users should carefully read and follow the instructions and precautions listed on the preservative system label when using them.
Is it safe to use pressure treated lumber for animal enclosures such as a bird feeder or fish pond retaining wall? I have heard that leaching may be a problem.
Outdoor enclosures for animals are an appropriate use for pressure treated lumber when you keep in mind a few factors. For ponds you will need to make sure that you choose a lumber a that is treated to the proper retention. The lumber end tag should note the end use as “Ground Contact/Freshwater Use.” A small amount of leaching takes place, and copper that is used in many pressure treated lumber does have aquatic toxicity. Generally the levels of leaching will only be problematic in situations where there is a large amount of treated wood compared to the volume of water and where there is a low water flow. For more information, the USDA Forest Product Lab discusses treated wood and environmental impact.
After my project is built, is any special maintenance necessary?
Left unfinished, treated wood ages gracefully, eventually softening to an attractive driftwood gray. On flat surfaces such as decks, however, leaves and other debris may collect and create unsightly stains. Even if your lumber has the locked-in protection of factory-applied water repellent, you'll want to follow an annual maintenance (pdf - 39 KB) program that includes a semitransparent stain or a sealant which contains an ultraviolet stabilizer. If you stain your project, a quality penetrating latex or oil base stain is recommended.
What else should I know about treated wood?
Decades of research and testing have gone into its development, and we certainly haven’t answered every question about it. However, a full line of free literature is available to you through your building materials dealer. Finally, you should be aware of this: lengthening a wood structure’s life through pressure treatment lowers the pressure on our planet’s exhaustible mineral and energy resources. Millions of trees are saved every year by pressure treatment. Treated lumber makes one tree last as long as many untreated trees. Use pressure-treated wood with confidence in its ever-lasting quality and safety. You’ll be protecting our environment’s major renewable building material.
