Types of Pressure Treated Lumber and Where to Use Them
| Type | Type | Location | Uses |
| UC1 | UC1 | Interior Dry | Stud framing & baseboards |
| UC2 | UC2 | Interior Wet | Sill & bottom plates, damp locations, ba ... |
| UC3 | A | Exterior Above Ground, Coated with Rapid ... | Protected decking, fascia & trim |
What is the best preservative for treated lumber?
- Alkaline copper quatenary (ACQ).
- Borates.
- Copper azole.
- Copper naphthenate.
- Copper-HDO (Bis- (Ncyclohexyldiazeniumdioxy-copper)).
- Polymeric betaine.
What do you need to know about treated lumber?
That being said, just try to take notice of the following things:
- Tint: If it has a greenish tint that generally means its treated with CCA or ACQ.
- Origin of the Wood: If you find a pallet, then I would doubt it would have been treated before use. ...
- Look for Stamps: Many times if wood is treated for construction, then they might have stamped it with a seal to notify you of what it was treated with. ...
Is treated wood stronger than untreated wood?
Pressure treated lumber is no stronger than untreated lumber. The difference between the two is that pressure treated lumber will resist the elements better than untreated, and so will maintain its integrity in conditions that would cause normal wood to rot.
What is the life span of the treated lumber?
Typical in-use life span of treated lumber used in swing sets, decks and deck posts is 10-20 years. Keep in mind that actual useful life and "warranty period" for any product may be quite different, and that warranties are usually limited in scope and conditions. Interestingly there are two different "life expectancy" issues for treated wood:
Why Does Lumber Treatment Type Matter?
Why do you use lumber treatment?
What is AWPA use category?
How is marine lumber treated?
What is ACQ in lumber?
What lumber is used for docking?
What is the best preservative for marine lumber?
See 2 more
What is the difference between #1 and #2 pressure-treated lumber?
If the wood is #1, it is stamped #1. The main difference between #1 and #2 is the slope of the wood grain, size, spacing, and the number of knots and holes, and the length of any splits. Construction grade is #1 and Standard is #2. Both can be used for load-bearing purposes or other outdoor applications.
What is the best grade of treated lumber?
The 5 Pressure Treated Lumber Grades Select structural, or SS, is the highest grade based on durability and strength. Standard grade lumber can be used for joists and other load-bearing applications.
What are the two basic types of pressure-treated lumber?
There are two basic types of pressure-treated wood....Ground-contact pressure-treated wood:Ground-contact pressure-treated lumber can be used either above ground or in contact with the ground.Has twice the level of chemical retention and protection compared to above-ground treated wood.More items...
What is the difference between treated wood and pressure treated wood?
Pressure-treated lumber is no stronger than regular wood, but it is also not any weaker. The difference between regular and pressure-treated lumber is that the treated wood has greater resistance to the elements and to pests. It, therefore, maintains its integrity not from being stronger, but from being rot resistant.
Which is better green or brown pressure treated wood?
As mentioned, the only difference between Green and Brown timber is the Brown dye used during preservation - this does make Brown timber slightly more expensive to buy. So, when a product is referred to as 'Green timber' you'll know that it's been treated but left in its natural colour.
Which is better #1 or #2 lumber?
Typically wood that is two or more inches thick is graded only for strength, denoted by #1, #2 and so on. And because stronger lumber has fewer and smaller knots, it's typically more attractive. So the general rule of thumb for lumber grades is this: the lower the number, the more strength and better appearance.
What does TP mean on lumber?
Timber Products Inspection, Inc. (TP) and its laboratories are accredited by the International Accreditation Service (IAS) and American Lumber Standard Committee (ALSC). TP's accreditations include inspection services for both preservative treated and fire retardant treated products.
Is severe weather lumber the same as treated lumber?
Compared to other treated products, Severe Weather with Ecolife is unsurpassed in performance and is preferred by many professional builders. The Ecolife preservative is a nonmetal-based, environmentally advanced preservative formulation.
What is the best treated lumber for deck?
Pressure-treated lumber is the best wood for outdoor decks when it comes to upfront costs because of its easy accessibility. However, pressure-treated lumber — and indeed, all types of traditional wood decking material — require the aforementioned rigorous, costly maintenance over time.
How long will ground contact pressure treated wood last?
40 yearsHow Long Does Pressure-Treated Wood Last? It depends on the climate, the type of wood, its uses, and how well it's maintained. While pressure treated poles can stay up to 40 years without any signs of rot or decay, decks and flooring might only last around 10 years.
How can you tell if old lumber is pressure treated?
New lumber that is pressure treated will have tags that identify the chemical used. More noticeably is the green or brown colors from the treating process. So newer wood is easier to identify as treated. As the treated wood ages it can turn a grey colour.
Why can't you use pressure treated wood inside?
Never use recycled pressure treated lumber indoors. There's a good chance it was treated with CCA, which means it contains arsenic. If you're going to leave the pressure treated wood exposed, perhaps as a post or an exposed rafter, plan on painting or finishing it.
What is the best pressure treated wood to use for a deck?
Pressure Treated Wood There are a few different types of wood that are commonly pressure treated for decks, but the two most popular are southern yellow pine and douglas fir.
What is the difference between standard and premium pressure-treated lumber?
Premium grades of pressure-treated wood are usually easier to find at lumber yards than at home centers. In addition to being drier, premium wood generally has fewer knots, resulting in a better looking deck. Kiln-dried wood is also lighter in weight and easier to handle than moisture-soaked boards.
What are the three categories of treated lumber Lowes?
There are three main families of treated lumber used in construction. Borate, Alkaline Copper Quat (ACQ) and other rot-resistant treatments, and non-combustible (Non-Com).
Is severe weather lumber the same as treated lumber?
Compared to other treated products, Severe Weather with Ecolife is unsurpassed in performance and is preferred by many professional builders. The Ecolife preservative is a nonmetal-based, environmentally advanced preservative formulation.
What is Pt lumber used for?
Some lumber is also treated for fire protection and used throughout different areas of residential, commercial, and industrial construction. There are many other uses for pt lumber, including docks, boathouses, sheds, boardwalks, play structures, gazebos, and the list goes on.
What is pressure treated wood?
Pressure treatment is an affordable alternative to expensive naturally rot-resistant lumber. The preservatives provide protection against rot, insects, mold, and fungi, so the wood lasts longer. Treated wood is made from strong evergreen species making it suitable for most building projects.
How Is Pressure Treated Wood Produced?
Pressure treatment of lumber has come a long way in the past 100 years. The current process is mostly computerized and mechanized using modern technology. The process is similar for treating milled lumber, plywood, posts, or utility poles against rot and insects.
What is ground contact lumber?
Ground contact means anything within 6-inches of the ground or in contact with the ground, foliage, grasses, or over water or wet areas. It may have poor drainage and air circulation, or like a sill plate, is difficult to repair or maintain. Pressure treated wood for ground contact commonly has twice the chemical retention level as above ground rated lumber. UC3B or UC4A are best for ground contact use.
What is premium grade lumber?
There is no structural premium grade, it is strictly a term for bright looking wood free of blemishes or knots.
What is the retention level of treated lumber?
The retention level is measured in pounds of chemical per cubic foot of wood (pcf). The longer the wood is in the pressure chamber, the greater the content of chemical preservatives forced into and retained in the wood.
What is CCA wood?
CCA is a mixture of chromium, copper, and arsenic that turns wood green. It was widely used as a preservative from the mid-1930s to 2004. A study by the EPA in 2000 deemed it too hazardous for residential use, and in 2003 the lumber industry agreed to stop using it for residential purposes.
Is Prowood FR fire retardant?
ProWood FR (Fire Retardant) is code compliant and UL approved. The pressure-treated fire-retardant chemical is infused deep into the wood cells, not just the surface, which helps stop the spread of flames and fire growth.
Does borate treated lumber stop termites?
Borate-Treated Lumber stops even the dreaded Formosan super termite in its tracks. Sill Plate like borate-treated lumber, it's guaranteed to stop termites and prevent decay. But unlike borate-treated lumber, it requires no special handling.
What is pressure treated lumber?
The pressure treated lumber boasts exceptional environmental qualities as far as carbon footprint, sustainability, and low-energy generation are concerned. Its life-cycle assessment is a testament to that. We have three major categories of treated lumber that are used in ...
How Long Will Pressure Treated Lumber Last in the Ground?
According to the Forest Products Laboratory, pressure treated wood pieces placed inside the ground can last up to 40 years or more without rotting.
How is wood treated in marine environments?
One way of protecting the woods in the harsh marine environments, the wood is pressure treated using a combination of water and preservatives that help keep the destructive pests away and reduce the speed of decay.
What is the best chemical to use to prevent wood from rotting?
The chemicals are good at penetrating deep into the wood, preventing rot due to water and pests in the process. CCA (chromated copper arsenate ) – This chemical combines chromium, copper, and arsenic that offers maximum protection. A lot of precautions must be in place when using woods treated with this chemical.
Why is pressure treated wood rotting?
Fungal Infestations. Infestation by fungi is another primary reason for the rotting of pressure treated wood. Fungi, tiny organisms, get into the wood and multiply; they feed on the wood and their continued presence results in the rotting.
What is ACQ in wood?
ACQ (alkaline copper quaternary) – This chemical has a quaternary compound that includes copper and ammonium. ACQ offers strong repellency against fungi, insects, and other marine animals that are out to damage the wood.
What happens to wood when left in a wet environment?
Wood in its natural state, when left in moist or wet environments, will soften very fast, which lets the fungus, bacteria, and other microorganisms invade it leading to wood’s decomposition. A pressure treated wood uses one of many compositions based on copper- a natural biocide that protects it from fungus and other microorganisms present in the moist areas.
How Can I Differentiate Treated Lumber?
Most pressure treated lumber will have an end tag to identify what type of chemicals it was treated with and whether it is rated for “ground contact” or “above ground use” only .
What is Treated Wood?
Like its name suggests, pressure-treated wood is wood that has been treated with chemicals while under pressure. Most treated wood is pressure-treated, but wood can also be surface coated. Surface coated means that the application of the preservative chemical is introduced by dipping, brushing or spraying the wood without being exposed to pressure. This is common when it’s necessary to treat the lumber or building components after they are installed.
Why Does Pressure Treated Lumber Warp?
This is referred to as Kiln Dried After Treatment (KDAT). Wood does most of its warping, twisting, and cupping as it dries. It’s hard to determine if you’re getting a straight board when it’s still wet.
Who Makes the Treated Lumber Rules?
The American Wood Protection Association (AWPA) is responsible for spreading voluntary wood preservation standards. AWPA standards are referenced in both the International Residential Code (IRC) and the International Building Code (IBC). The Use Category System (UCS) designates what preservative systems and retentions have been determined to be effective in protecting wood products under specified exposure conditions. All wood products can be placed into one of five major Use Categories that clearly describe the exposure conditions that specified wood products can be subjected to in service.
Do I Need Special Fasteners for Treated Wood?
Yes, fasteners such as nails, screws, and bolts used on treated wood needs to be hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Check the label on the fasteners to see if they will work with your treated wood.
Does Treated Wood Corrode Aluminum?
Yes. Most of the new chemical treatments contain copper and should never come in direct contact with aluminum. Total failure caused by corrosion can occur in less than a year. Many contractors isolate aluminum flashing and trim from pressure treated lumber with building tape or house wrap.
What is pressure treated wood?
Like its name suggests, pressure-treated wood is wood that has been treated with chemicals while under pressure. First, untreated lumber is placed into a large horizontal treating cylinder. The door is sealed and a vacuum is applied to remove most of the air from both the cylinder and the cells of the wood in the process.
What is treated wood used for?
Treated wood is used for projects that can include pier pilings, decks, interior framing, outdoor wooden walkways, porch railings, fencing, and more. Your contractor can help you choose the ideal treated wood for the project you have in mind.
What is modified wood?
Modified wood typically refers to wood that’s been heated. You’ll often hear it referred to as thermally modified wood. This type of wood is increasing in popularity because it’s both functional and eco-friendly. Usually, no chemicals are used to treat the wood. Instead, it is heated in a 400-plus degree, oxygen-free environment. It’s literally cooked. The heat treatment permanently changes some of its characteristics, making it more durable and more ideal for various uses.
What is Charred Wood/Shou Sugi Ban?
Charring wood is a weatherproofing treatment that helps protect the wood from moisture and insects. This practice originated from the Japanese technique of shou sugi ban, which chars the woods exterior using a light open flame. The Japanese have been using this technique since roughly the 18th century. They tend to use cedar for the procedure because it’s always endowed with natural moisture-resistance properties.
What is Reclaimed Barn Wood?
Reclaimed wood is a trendy option for home design today. However, unlike trends that come and go, reclaimed barn wood has staying power. Salvaged from other buildings, the wood has stood the test of time and frequently boasts a rich patina that enhances its antique look. It is essential to choose wood that isn’t warped. Also, many vendors today sell reclaimed wood that’s been heat-treated to make it even more durable and pest resistant. Today, people use reclaimed barn wood for both interior and exterior projects. It’s ideal for porch posts, mantelpieces, stair rails, flooring, and more.
Why is charred wood considered a good wood?
Shou sugi ban and charred woods in general function well when it comes to standing up to moisture and insect pests. However, they’re often favored because of their aesthetic appeal. In fact, many interior designers and architects around the globe are opting for charred wood because of its unique appearance.
What is untreated wood?
Untreated wood is the raw material—plain old wood or lumber. Certain kinds of wood are endowed with natural properties that make them better for certain types of projects. Cedar and teak, for example, have properties that make them naturally better at standing up to moisture. That’s why people often choose them for outdoor projects like decks and railings.
Do treated woods last forever?
While modified and treated woods won’t last forever, they are popular options because they last longer and perform better under various conditions. Use the following information to help you select a wood type for an upcoming project or home renovation .
Clearing up treated lumber tag confusion
The amount of chemical treatment needed to preserve wood depends upon the chemicals used. Read the treatment tags carefully to get what you need.
How to identify types of pressure treated wood treatment levels
When you’re buying treated lumber, look at the tag on the end to find out the type of chemical treatment and the preservation retention level.
Lumber Definitions
Lumber is sold in various forms, sizes, types and cuts. These characteristics are used to describe the different types of wood lumber. Certain projects may require one or more of these specific traits.
Wood Basics
In addition to the basic lumber definitions, there are two kinds of wood from which to choose: hardwood and softwood. The terms have almost nothing to do with the actual hardness of the wood. There are certain characteristics that are common in all wood types.
Hardwood Grades
Grading designation depends on the number of defects in a board. A lower grade can be perfectly acceptable, depending on placement and usage. Hardwoods are graded by the National Hardwood Lumber Association. Here are the features of each grade.
Softwood Grades
Softwoods are divided into two categories: dimensional lumber, with a grade based on strength, and appearance boards, which are typically used for woodworking projects. Grades listed here are from highest to lowest.
Lumber Grade Stamp
While lumber of the same species and size is at the mill, it's designated and separated by grade. It's then identified by a stamp and often inventoried by its grade and species. When selecting wood, look for its grading stamp because different lumberyards sometimes use different names for the same grade.
Treated Lumber
Treated lumber is produced for exterior use only and pressure-treated for ground or aboveground contact. It's resistant to rotting and insect damage, making it ideal for projects like DIY garden beds. Boards can be painted or stained once dry. Make sure you choose the right fastener (galvanized or stainless steel) when working with treated lumber.
Dimensional Lumber and Studs
Dimensional lumber and studs are milled on all four sides. Available in different lengths, these products are used for a variety of wood projects and construction.
What is Pressure Treated Wood?
Pressure-treated wood has gone through a process that uses high pressure to force a solution of water and preservative agents deep into the lumber to help extend its useful lifespan.
Types of Pressure-Treated Wood
There are two basic types of pressure-treated wood. Individual pieces of pressure-treated lumber will have a tag on one end of the board to indicate its permitted use.
Uses for Pressure-Treated Wood
Decks and fences are the most common uses for treated wood, but it is ideal for a variety of applications. Pressure-treated decking can extend the longevity of wooden walkways, freshwater docks, accessibility ramps and other outdoor structures that are exposed to the elements.
Why Does Lumber Treatment Type Matter?
There’s a common misconception that all treated lumber is created equal, but each kind has its own unique properties and applications. If you want your dock or deck to be safe, durable, and compliant with local building codes, you need to understand the differences between types of pressure-treated lumber.
Why do you use lumber treatment?
These treatments help protect lumber from rot, moisture, and burrowing pests—and to prevent the treatment in your lumber from seeping out into the environment. This lumber can often be used in environments where occasional saltwater contact is likely, such as framing over saltwater. Lumber that isn’t safe for ground contact will wear away faster and may even cause damage to the flora and fauna surrounding it.
What is AWPA use category?
The AWPA Use Category system gives contractors and homeowners a simple way to understand and apply AWPA Standards. In the AWPA Use Category system, all types of treated wood can be sorted into categories based on how well it holds up in different applications.
How is marine lumber treated?
To prepare it for harsh marine environments, wood is pressure treated with a combination of water and preservatives to keep pests away and slow the rate of decay. Different preservatives are suited for different applications and types of wood. Let’s go over some of the most common treatments you’ll see in marine lumber.
What is ACQ in lumber?
ACQ (alkaline copper quaternary) – Contains a quaternary compound including copper and ammonium. ACQ is strong against fungi, insects, and other marine creatures that may damage the integrity of lumber.
What lumber is used for docking?
For decks and docks of all kinds, many contractors choose UC4B and UC4C for the decking and framing. Experienced contractors know that you need to have lumber that is certified for “ground contact” or higher for humid, harsh, or near water applications.
What is the best preservative for marine lumber?
Let’s go over some of the most common treatments you’ll see in marine lumber. MCA (micronized copper azole) and CA (copper azole) – Copper-based preservatives suitable for above-ground, below-ground, and freshwater uses. These treatments penetrate deep into lumber to prevent rot from water exposure and pests.
