what does 1.6 in lumber pressure treatment mean

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How to identify pressure treated wood from non-pressure treated?

Here’s a simple guide to identifying pressure treated wood from non-pressure-treated wood. To tell if the wood is treated, check tags, stamps, and markings of chemicals used. Smelling can also help you know if wood is treated. Treated lumber can smell oily, while untreated wood doesn’t.

What is pressure treated lumber made of?

Modern chemical baths and pressurization began in the early half of the 20th century. Today, pressure treated lumber for residential use is commonly pine, spruce, or fir that has been immersed in a water-based chemical bath of preservatives. Pressurization then forces the liquid deep into the wood.

How long does pressure treated lumber last?

It needs to be treated every 2 to 3 years (depending on the environment) to protect it from moisture damage. Pressure treated lumber has been treated with a chemical solution to protect it from insects, mold, mildew, and rot. There are different types of treatment and lumber grades for different uses.

What is the difference between 1 grade and 2 grade pressure treated?

A walk down the lumber aisle or through a lumberyard will provide some understanding of the differences between #1 and #2 grade pressure treated lumber, or increase your confusion. The most noticeable difference may be the price and scarcity of #1 grade lumber.

What does number in pressure-treated lumber mean?

A-The numbers on pressure-treated wood refer to the levels of preservative treatment and are important because they designate the intended uses of the wood. The numbers commonly used are LP-2, LP-22, 0.25 and 0.40.

What is the difference between number 1 and number 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 does #2 pressure-treated lumber mean?

Grades of pressure treated wood Pressure treated wood is sold with the lumber grades Premium, Select, Number 1, Number 2, and Number 3. The higher the grade, the fewer the defects—that is splits or knots. In general, you will want to choose Number 2 grade boards, or higher, for decks.

What are the different grades of pressure-treated lumber?

Pressure-treated lumber comes in 5 different grades: Premium, Select, and Number 1, 2, and 3. The higher the grade, the fewer the knots, splits, and general defects. For constructing a backyard deck, Number 2 or higher grade boards are required by code and are preferred by experienced carpenters.

Is #1 or #2 lumber better?

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 is the difference between green and brown pressure treated wood?

Brown timber is a traditional dark brown coloured wood, which follows the same pressure treated process as green timber to extend the timbers life but the only difference is to achieve the brown colour, a brown dye is added to the copper preservative mix.

What is the difference between #1 and 2 grade lumber?

#1 Grade: When appearance becomes more of a factor, #1 Grade will contain smaller, fewer, sound, tight knots and have less wane than found in #2 Grade. Keep in mind, that with the introduction of Prime grades, #1 Grade no longer contains some of the better grades that used to be included.

What is #3 grade lumber?

Table 2: Lumber Grades for Common (nonstress-graded) LumberGradeDesignationTypical UsesNo. 1ConstructionSiding, shelving, panelingNo. 2StandardSimilar uses to No. 1No. 3UtilitySheathing, subflooring, crate constructionNo. 4EconomySheathing, subflooring, creation of forms for concrete work1 more row

What does #2 grade wood mean?

2 Lumber. No. 2 lumber is the most common grade for framing. Lumber of this grade contains few defects, but knots are allowed of any quality as long as they are well spaced and do not exceed the size regulations.

What is the best lumber grade?

Hardwood grades are: FAS (First and Second) is the highest grade of hardwood lumber. It's usually 6-inches x 8-inches and is 83 percent defect-free on its best side. Select is 4-inches x 6-inches and 83 percent defect free on its best side.

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 is AC2 lumber treated with?

MicroPro® AC2® pressure treated wood is treated using a waterborne copper preservative system developed to provide long-term protection for wood used in exterior applications.

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 are the active ingredients in treated wood?

Active Ingredients in Treated Wood: MCA, CA, ACQ, and CCA. Another important acronym to pay attention to on a lumber label is the type of preservative that was used to treat the wood.

What is AWPA in building?

The American Wood Protection Association (AWPA) is a non-profit organization that has long set the standards for treated wood used in residential and commercial applications. AWPA Standards are purely informational, but they are often referenced in federal, state, and local building code laws.

What is the AWPA standard?

The AWPA Standards describe ways to handle wood to maintain its longevity and protect the environment. In these standards, the AWPA classifies wood treatment types depending on where and how they can be used.

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.

Is treated lumber bad for the environment?

Using improperly treated lumber is bad for the wood, the environment, and your wallet. So if you’re a homeowner or contractor who isn’t 100% up to speed with the different classifications of treated lumber, let’s break things down.

Is CCA approved for residential use?

Because of its chemical content, CCA is approved for marine construction but not for most residential applications (like in homes, fences, or furniture). Source: US Forest Products Laboratory. All of these treatments are water-based (as opposed to oil-based).

The 5 Pressure Treated Lumber Grades

Pressure-treated lumber comes in 5 different grades: Premium, Select, and Number 1, 2, and 3. The higher the grade, the fewer the knots, splits, and general defects. For constructing a backyard deck, Number 2 or higher grade boards are required by code and are preferred by experienced carpenters.

How Are Grades Determined?

Many different types of wood are used in lumber, so there is a variety of properties, strengths, and appearances. Different species are used in deck framing and structure framing, for example.

AWPA Categories

There are other systems used to classify pressure-treated lumber. The American Wood Preservers’ Association utilizes a 12-tier system to guide wood use. For example, UC1 and UC2 mean a piece of lumber should be used for interior projects, while UC5 is wood that can be safely immersed in saltwater.

Retention Levels

In addition to the different grades and AWPA categories, pressure-treated wood retention levels are also used to differentiate types of lumber.

Preparing Wood for Pressure Treatment

The purpose of wood pressure treatment is to force preservative chemicals deep into the cellular structure of the wood. The chemical acts as a barrier between the wood and biological deterioration agents, so that the service life of the wood can be substantially increased.

Treatment Processes

In a typical pressure treatment process, wood is placed in a horizontal cylinder up to 150 ft. long and 7 ft. in diameter as shown in Figure 3. The cylinder is flooded with the chemical followed by a cycle of pressure and vacuum. Pressure treatment methods are classified into two basics groups: full-cell and empty-cell processes.

Preservative Chemicals

Preservative chemicals used for the pressure treatment process can be classified into three groups: tar oil based, oil-borne, and water-borne preservatives. Creosote is the most commonly used tar oil preservative chemical. It is often called coal tar creosote because of its close relationship to toluene, benzene, and tar.

How To Tell if Wood is Treated

To tell if the wood is treated, check tags, stamps, and markings of chemicals used. Smelling can also help you know if wood is treated. Treated lumber can smell oily, while untreated wood doesn’t. Treated wood also has a green or brown hue from the treatment process.

What Does Treated Wood Mean?

Treated wood refers to lumber that has undergone pressure treatment. In it, wood is placed in a pressure chamber full of liquid preservatives. High pressure is used so that the preservative will penetrate the lumber.

How do you Know if wood is Pressure Treated

All lumber may look the same, but you don’t need to be intimidated. Once you know the signs, you can identify pressure-treated wood.

Pressure treated Wood Color

As you already know, the color always matches with the chemicals used for wood pressure treatment.

How to Tell if Old Wood is Pressure Treated

Look for the greenish tint. Wood’s color changes after pressure treatment. It usually has a greenish tint unless the lumber has faded and turned to gray.

How to Tell if Plywood is Pressure Treated

Change in color. Treated plywood can have a green or brown color, a result of the treatment process.

How to Tell if Wood is Treated for Burning

Never burn pressure treated wood as this would release its chemicals. Plus, its ash is equally toxic. In short, there’s no pressure-treated wood that is meant for burning.

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.

When did the EPA start removing CCA from lumber?

In 2003, the EPA arranged a voluntary agreement with manufacturers of wood treatment chemicals to remove lumber treated with CCA from most residential construction uses.

Is treated wood treated or surface coated?

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.

Can you use zinc coated steel on 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.

Can you dry treated lumber in a kiln?

Most dimensional lumber is dried in a kiln, but treated wood is not dried after treatment. There are exceptions to this, such as foundation grade lumber and plywood, which needs to be dried to a moisture content of no more than 19 percent for lumber and 15 percent for plywood. This is referred to as Kiln Dried After Treatment (KDAT).

Does treated wood soak up water?

One common misconception is that treated wood is more resistant to water, but that’s not true. Treated wood will soak up just as much water as non-treated wood. 2 / 10. Courtesy SWPA.

Is there arsenic in pressure treated lumber?

There is still some arsenic in some pressure treated lumber, but not as much as there used to be . For many decades one of the most common preservatives used in the residential construction industry has been Chromated Copper Arsenate (CCA).

Understanding Incisions in Pressure Treated Lumber

In this section, we want to give you a little more information about the incisions in treated lumber. Some people are very familiar with seeing these little dents in the side of their wood. However, others are not.

How to Get Rid of Incisions in Pressure Treated Lumber

So, you’re trying to build the finest deck in town, but you realize the pressure-treated lumber you ordered is checkered with small incisions. Is there anything you can do to improve the appearance of your deck?

Conclusion

Pressure-treated lumber sometimes needs incisions to help the lumber accept the preservative. However, not all pressure treated lumber has these marks.

When did wood stop being treated?

On December 31, 2003, the U.S. wood treatment industry stopped treating residential lumber with arsenic and chromium ( chromated copper arsenate, or CCA).

What is industrial wood preservation?

In most countries, industrial wood preservation operations are notifiable industrial activities that require licensing from relevant regulatory authorities such as EPA or equivalent. Reporting and licensing conditions vary widely, depending on the particular chemicals used and the country of use.

How to protect wood from decay?

Probably the first attempts made to protect wood from decay and insect attack consisted of brushing or rubbing preservatives onto the surfaces of the treated wood. Through trial and error the most effective preservatives and application processes were slowly determined. In the Industrial Revolution, demands for such things as telegraph poles and railroad ties (UK: railway sleepers) helped to fuel an explosion of new techniques that emerged in the early 19th century. The sharpest rise in inventions took place between 1830 and 1840, when Bethell, Boucherie, Burnett and Kyan were making wood-preserving history. Since then, numerous processes have been introduced or existing processes improved. The goal of modern-day wood preservation is to ensure a deep, uniform penetration with reasonable cost, without endangering the environment. The most widespread application processes today are those using artificial pressure through which many woods are being effectively treated, but several species (such as spruce, Douglas-fir, larch, hemlock and fir) are very resistant to impregnation. With the use of incising, the treatment of these woods has been somewhat successful but with a higher cost and not always satisfactory results. One can divide the wood-preserving methods roughly into either non-pressure processes or pressure processes.

What is borate treated wood?

Borate treated wood is of low toxicity to humans, and does not contain copper or other heavy metals. However, unlike most other preservatives, borate compounds do not become fixed in the wood and can be partially leached out if exposed repeatedly to water that flows away rather than evaporating (evaporation leaves the borate behind so is not a problem). Even though leaching will not normally reduce boron concentrations below effective levels for preventing fungal growth, borates should not be used where they will be exposed to repeated rain, water or ground contact unless the exposed surfaces are treated to repel water. Zinc-borate compounds are less suspectible to leaching than sodium-borate compounds, but are still not recommended for below-ground use unless the timber is first sealed. Recent interest in low toxicity timber for residential use, along with new regulations restricting some wood preservation agents, has resulted in a resurgence of the use of borate treated wood for floor beams and internal structural members. Researchers at CSIRO in Australia have developed organoborates which are much more resistant to leaching, while still providing timber with good protection from termite and fungal attack. The cost of the production of these modified borates will limit their widespread take-up but they are likely to be suitable for certain niche applications, especially where low mammalian toxicity is of paramount importance.

How long does coal tar creosote last?

A thorough brush or spray treatment with coal-tar creosote can add 1 to 3 years to the lifespan of poles or posts. Two or more coats provide better protection than one, but the successive coats should not be applied until the prior coat has dried or soaked into the wood. The wood should be seasoned before treatment.

What is a wharf piling?

A modern wharf piling bored by bivalves known as shipworms. As proposed by Richardson, treatment of wood has been practiced for almost as long as the use of wood itself. There are records of wood preservation reaching back to ancient Greece during Alexander the Great 's rule, where bridge wood was soaked in olive oil.

Is ACQ treated wood corrosive?

Since it contains high levels of copper, ACQ-treated timber is five times more corrosive to common steel. It is necessary to use fasteners meeting or exceeding requirements for ASTM A 153 Class D, such as ceramic-coated, as mere galvanized and even common grades of stainless steel corrode.

What is Wolmanized wood?

Wolmanized®pressure-treated wood is treated to various retention levels that are intended to protect the wood for particular applications. Retention levels indicate the amount of preservative retained in the wood in a specific assay zone. In North America,retention is expressed in pounds per cubic foot (pcf).

What is arch wood protection?

Arch Wood Protection and Arch Treatment Technologies produce wood preservatives and additives that enhance the qualities of wood by pressure treatment processing.The companies are licensors of a list of other respected brands of treated wood:

Preparing Wood For Pressure Treatment

See more on extension.okstate.edu

Treatment Processes

Preservative Chemicals