What Is Treated/Pressure-Treated Wood?

Treated wood is wood that has been appropriately treated with preservative chemicals with the intent of prolonging its intended usefulness lifecycle compared to untreated wood.

The active ingredients commonly used in treated wood are alkaline copper quaternary (ACQ), copper azole (CA) or micronized copper azole (MCA). These compounds react with the wood fibers to slow natural decay and have properties to resist termites, fungus, moisture and other elements that promote rot and cause structural degradation.

Advantages of Treated Wood

Life Cycle Comparison of untreated wood vs. treated wood

Because treated wood is intended to extend the usefulness and life of wood, fewer trees are required to perform the same function that is required when untreated wood is used.
Wood that has been appropriately treated can significantly reduce the number of trees that would otherwise need to be harvested.

If untreated wood only lasts 5 years and treated wood lasts 25 years or more, it would take at least 5 times as many trees over the same period of time, as well as the incremental labor, to continually harvest, manufacture, replace and dispose of all of the untreated wood.

Unprotected wood can begin to rot within 1-2 years depending on the environment.
The structural integrity of untreated wood can be greatly reduced within weeks due to termites and certain marine organisms.

Without chemical treatments, wood can be quickly consumed when exposed to flames.

Common Preservative Protection Use Categories

The Use Category System of the American Wood Protection Association (AWPA) designates what preservative systems and retentions have been determined to be effective in protecting wood products under specified exposure conditions. The Use Category is designated on the end tag of each piece of treated lumber.

  • Fungal rot/decay and termite protection
  • Outdoor, exposed applications
  • Interior framing
  • Marine organisms
  • Dock/pier pilings
  • Fire Retardant Treated Wood (FRTW)
Use CategoryBrief Description
UC1Interior Dry
UC2Interior Damp
UC3AExterior Above Ground, Coated with Rapid Water Runoff
UC3BExterior Above Ground, Uncoated or Poor Water Runoff
UC4AGround Contact, General Use
UC4BGround Contact, Heavy Duty
UC4CGround Contact, Extreme Duty
UC5AMarine Use, Northern Waters (Salt or Brackish Water)
UC5BMarine Use, Central Waters (Salt or Brackish Water)
UC5CMarine Use, Southern Waters (Salt or Brackish Water)
UCFAInterior Above Ground Fire Protection
UCFBExterior Above Ground Fire Protection
Font: https://awpa.com/images/standards/ResidentialInfographic2021.pdf

Pressure-Treated

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.
This preservation process enables pressure-treated fence posts, for example, to withstand years of being embedded in soil.
Because pressure treated wood absorbs a significant amount of liquid during the manufacturing process, it typically arrives at stores still wet and can take up to several weeks to completely dry out. The preservatives remain in the lumber after the water evaporates.

Categories of Pressure Treatments

Waterborne treated lumber is generally used in building structures that are residential, commercial and industrial.
Creosote-treated lumber is mostly used for treating guardrail posts, railroad ties, and timbers used in marine structures.

Oil-borne treated lumber is used for treating utility poles and cross arms.

Pressure-impregnated Treatments

In pressure-treated wood, preservatives are infused into the wood, beyond just the surface.
Pressure Treatment (PT) is the general term to describe the process for infusing/impregnating the wood fibers with preservative chemicals and removing any excesses, leaving behind only enough chemical in the wood fibers (retention) to protect the wood. The AWPA sets appropriate chemical retentions depending on their intended use/requirements based on performance data derived from long-term scientific tests. The AWPA wood preserving standards are reviewed by their technical committees every five years to ensure that retention levels are appropriate and that a given preservative formulation is performing as expected.

Topical/Surface Treatments

Topical/surface treatments usually limit protection to the surface area because it is applied by brushing, spraying or dipping.

Although regularly coating a surface with a paint or sealer may help protect wood from the elements, it won’t necessarily prevent it from rotting or being attacked by insects.

Additional Treatments

While older pressure-treated wood must be periodically treated with a sealant to lock in the dangerous arsenic chemicals, newer pressure-treated must also be coated with sealant to protect the wood from weathering and corrosion. The best way to think about this issue is that pressure-treatment protects the wood from internal decay, while sealant protects the wood from external damage. Sealant also prevents the wood from drying to fast which will cause excessive warping. Pressure-treated wood can also be painted or stained, but the wood must first be allowed to dry for one to two months to enable proper adhesion.

Font: Viance treated wood

References

  • https://awpa.com/info/technical/homeowners
  • www.treatedwood.com/learn/what-is-treated-wood
  • www.homedepot.com/c/ab/types-of-pressure-treated-wood/9ba683603be9fa5395fab9052c50759
  • www.homeadvisor.com/r/benefits-of-pressure-treated-wood/

Maintenance and Care of your Cabinet

Wood products require special care and knowing that we have some tips that can make increase the lifetime of your cabinet.

The wood surfaces, being natural, have characteristics such as burl grain, open knot, Bird’s eye, mineral streak, Heartwood**

Font: J&K Cabinets

As a general rule, keep all cabinet surfaces dry at all times.

Cabinet surfaces shall be dried immediately with a soft, lint-free cotton cloth or paper towel.
Avoid using a dish cloth or sponge. Avoid ammonia-based cleaners and soaps with dye, Harsh detergent residues may harm cabinet finishes.

As with all wood products, quick temperature changes and excessive moisture can be harmful to the cabinet finish and overall cabinet stability.

Basic Cleaning

To remove dust after installation and for initial cleaning, use a soft, lint-free cotton cloth to wipe down all exterior and interior surfaces.

For regular basic cleaning, use a soft, lint-free cotton cloth dampened with a mild detergent or soap and warm water. For best results, use a blotting action rather than a wiping motion, when cleaning.

Wipe up food spills and water spots immediately with a lint-free cotton cloth, so moisture is not absorbed into the cabinet surfaces.

Cleaning of glass door insert

Use a household glass cleaner with a soft, clean cloth.
Apply the glass cleaner directly to the cleaning cloth rather than on the glass or mirror surface.
Avoid excess glass cleaner running into the cabinet joints.
Ammonia should never be used in full strength

Basic care and things to avoid

  • When in doubt of a cleaner’s suitability, DO NOT USE.
  • Never use scouring pads, stell wool, wire brushes or powdered cleaners.
  • Never leave a cloth moistened with cleaner on any cabinet surface for any lebgth of time.
  • Check the areas around the sink and dishwasher to make sure that water and detergentes do not dry on the cabinet surfaces.
  • Avoid draping wet or damp dish towers over doors of the base cabinets.
  • Do not attach towel racks to the interior of base cabinets doors.
  • Avoid placing small kitchen appliances where the heat os steam is directed onto cabinet surfaces.
  • Do not leave printed materials (newspapers, magazines, etc.) on the cabinet surfaces, as the printing can bleed into the cabinet finish.

*A burl is a growth on a tree formed from unsprouted bud tissue. The burl forms large, knobby looking growths on the base and trunk of the tree.

**An open knot may occur in the form of a very small pin-sized hole to a large gaping hole in the lumber surface.

***Bird’s eye is a type of figure that occurs within several kinds of wood, most notably in hard maple. It has a distinctive pattern that resembles tiny, swirling eyes disrupting the smooth lines of grain. It is somewhat reminiscent of a burl, but it is quite different: the small knots that make the burl are missing.

****A mineral streak is an area of the wood that has a different color due to its mineral content. Mineral streaks are often considered to add value and appeal to the wood. A mineral streak is a black, grey or olive line or band in the wood, and it develops when the tree absorbs and deposits minerals from the soil.

*****Heartwood, also called duramen, dead, central wood of trees. Its cells usually contain tannins or other substances that make it dark in colour and sometimes aromatic. Heartwood is mechanically strong, resistant to decay, and less easily penetrated by wood-preservative chemicals than other types of wood.

References

  • redwoodburl.com/burl-wood/#:~:text=Burl%20is%20a%20grain%20characteristic,and%20trunk%20of%20the%20tree.
  • www.woodcraftind.com/downloads/WoodcraftIndustries-Wood-Characteristics.pdf
  • https://en.wikipedia.org/wiki/Bird%27s_eye_figure#:~:text=Bird’s%20eye%20is%20a%20type,make%20the%20burl%20are%20missing.
  • https://kitchencabinetkings.com/glossary/mineral-streak/
  • www.britannica.com/science/heartwood

HARDWOOD VS. SOFTWOOD Understanding the difference

Wood is often classified into two categories including hardwood and softwood. But, the difference between these two types of wood isn’t in their name. That is, hardwood isn’t necessarily denser than softwood.
For instance, yew wood is classified as a softwood but is considerably tougher than certain hardwoods. Likewise, balsa wood is classified as a hardwood and yet it’s one of the least dense and softest types of wood.

So what’s the difference between hardwood and softwood if the difference isn’t in their name?

What makes a wood hard or soft?

To classify a wood as hard or soft depends on the seeds that the tree produces. A wood will be classified as a hardwood if the seeds that the tree produces have a coating. These coatings can either take the shape of a fruit or a shell.
A wood will be classified as a softwood if the seeds don’t have any type of coating and are instead dropped to the ground and left to the elements.

Hardwood trees are angiosperms, plants that produce seeds with some sort of covering. This might be a fruit, such as an apple, or a hard shell, such as an acorn.

Softwoods, on the other hand, are gymnosperms. These plants let seeds fall to the ground as is, with no covering. Pine trees, which grow seeds in hard cones, fall into this category. In conifers like pines, these seeds are released into the wind once they mature. This spreads the plant’s seed over a wider area.

For the most part, angiosperm trees lose their leaves during cold weather while gymnosperm trees keep their leaves all year round. So, it’s also accurate to say evergreens are softwoods and deciduous trees are hardwoods.

What types of trees are hardwood and softwood?

Hard wood is the wood that comes from flowering plants, also known as angiosperm. Angiosperm is a Greek term meaning “vessel seed.”

These types of trees include walnut, maple, and oak trees. However, hardwood trees don’t include monocots like palm trees and bamboo.

Softwood is the wood that comes from gymnosperm trees, which have needles and produce cones. Gymnosperm is a Greek term meaning “naked seed.” These trees are usually evergreen conifers such as spruce or pine trees.

What the difference in the physical structure of hard and softwoods?

There is a physical difference between hardwoods and softwoods, but it isn’t in the density of the wood. Hardwoods typically have very broad leaves (think of maple and oak leaves). Softwoods have cones and needles.
Hardwoods and softwoods also differ on a microscopic level. For instance, hardwoods have pores whereas softwoods don’t. These pores allow the hardwood to transport water throughout the wood to keep the tree healthy.
These pores are what creates the visual difference between the softwood and hardwood grain. Softwood has a light grain because it has no visual pores whereas hardwood grain is prominent.

What can hardwood and softwood be used for?

There are also differences between how hardwood and softwood can be used, although they’re sometimes used for the same application. In this instance, the type of tree being used comes into play because of how dense the wood will need to be.

Hardwoods are oftentimes denser than softwoods. For this reason, they’ll be used for flooring, construction, decks, and high-quality furniture.

Softwoods aren’t always dense, but they do have a wide range of applications. For instance, softwood is used for framing lumber, such as studs, joists, and beams. It is also used for trim and finish components such as doors or windows. It can also be used for engineered products, like plywood, OSB, and paper

Characteristics Softwood Hardwood
DurationLess durable wood.Hardwoods are highly durable and last for several decades.
Ring structureDistinct annual rings are found.The annual rings are not distinct.
Medullary raysIndistinct medullary rays.Distinct medullary rays.
Growth rateSoft wood trees grow faster than hardwood trees.The growth rate of this type of trees is slower.
Wood branchingCreates more branch or shoots.Have fewer shoots.
Tensile and shear strengthWell tensile and comparatively weaker shear strength.Good tensile and shear strength.
CostLess expensive.More expensive.
UsesPaper pulp, paper, solid wood products, Woodwares like homes and cabins and also for furniture.Generally flooring and furniture. Also used for papermaking.
ExampleBlack willow (Salix nigra), Redwood (Sequoioideae sp).Sugar maple (Acer saccharum), Eucalyptus (Eucalyptus globulus).
(Font: https://www.texastrees.org/american-chestnut-tree/)

References

  • https://www.horizonwood.com/hardwood-vs-softwood-understanding-the-difference-part-1/
  • https://science.howstuffworks.com/life/genetic/question598.htm
  • https://civiltoday.com/civil-engineering-materials/timber/150-difference-between-softwood-and-hardwood
  • https://www.easybiologyclass.com/difference-between-hardwood-and-softwood/
  • https://www.texastrees.org/american-chestnut-tree/

Density of various wood species

Density of various wood species

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.

Density: The strength and weight of wood is its density. Denser wood is best for furniture and building, while less dense wood can be used in making aircrafts, woodworking projects and even making paper.

Texture: Texture is the wood property that determines the condition of the surface and its stability. It plays an important role in deciding how a wood is finished.

Color: Color contributes to the personality of wood. For example, red cedar will give you a very different look and character than white pine.

Woodgrain: Each tree has its own grain pattern, so two boards of the same species can look very different. Woodgrain is the direction in which the wood cell fibers grow. These variances in grain direction can have a significant impact on your project.

The density of wood differs depending on tree species and tree growth environment. Even the parts of the tree have different densities: branches usually have a lower wood density compared to the trunk.

Video

Wood density influences timber classification and scheduling for appropriate use. This table gives information about the relationship between timber hardness and density.

*The data used are for air-dry density, that is, the wood at 12% moisture content, which is the average equilibrium moisture content for internal environments in Queensland.

Font: qtimber Queensland Government

For many end uses, density variation is at least as important as the average density. Variability is most obvious at a species level, where big differences are recognized and published (USDA 1999) often arising from characteristic patterns originating at the individual growth ring level. For instance, earlywood values are typically in the range 200–400 kgm−3 compared to latewood values of 600–900 kgm−3 (Fig. 1) (Josza and Middleton 1994). Users are very conscious of the inherent variability of wood density within species and even within individual tree stems, and a great deal of research has looked at this aspect.

Font: https://en.wikipedia.org/wiki/Janka_hardness_test

References

  • www.sciencedirect.com/topics/agricultural-and-biological-sciences/wood-density
  • www.lowes.com/n/buying-guide/lumber-buying-guide
  • www.engineeringtoolbox.com/wood-density-d_40.html
  • www.mtcopeland.com/blog/wood-density-explained-plus-wood-density-chart/
  • qtimber.daf.qld.gov.au/guides/wood-density-and-hardness
  • en.wikipedia.org/wiki/Janka_hardness_test

Composite Lumber

Until the 1990s, wood was the material of choice for deck construction. However, new products, composites, began to emerge at this time. These new products offered the look and workability of wood, but they were more water resistant and required less maintenance. Over time, these lower maintenance decking options increased in popularity. Although the majority of decks are still built of pressure treated pine, redwood, cedar or mahogany, use of composite woods has increased as outdoor decks and living areas have become popular as home features.

Working with composite lumber is similar to working with wood. However, composite lumber has the added benefit of being less likely to split or delaminate. Some composite lumber is also engineered to be lighter weight for easier handling. Composite lumber is also more stain, scratch, and mold resistant, and is therefore supposed to have a longer life than wood lumber

It can be manufactured in a variety of colors, eliminating the need for paint, and with a comparable appearance and feel to timber. You can choose the style that suits exactly what you want, often with wind and UV resistant properties.

Types of wood composite products

If you are visiting your own hardware store, then what composite wood materials might you find? Plywood is considered the original composite wood product, manufactured from sheets of cross-laminated veneer which are bonded with moisture-resistant adhesives under heat. Fiberboard is another, made by combining wood fibers with wax and a resin binder under high temperatures and pressure, while particle board is manufactured from wood chips or sawmill shavings pressed with a synthetic resin.

Wood composite is usually made from the same hardwoods and softwoods used for lumber, except using the sawmill’s scraps and wood waste, and created by mixing ground wood particles with heated thermoplastic resin. Some combine and process the materials into pellets which are re-melted and formed into the final shape, while others create the final product by a one-step mixing and extrusion process.

Both virgin and recycled thermoplastics are used, with polyethylene-based products the most common. UV stabilizers, colorants, coupling agents and lubricants can also be added to create a product specifically targeted to its application, with both solid and hollow shapes formed.

What Is a Composite Decking Board Made Of?

Equal parts of wood fiber and plastic are mixed with pigments, ultraviolet inhibitors, and borate preservatives, then usually heated and extruded. The texture, if any, is embossed onto the warm surface before it cools.

Waste Wood: Ground-up wood from mills and furniture factories

Recycled Plastic: Shredded polyethylene from milk jugs and shopping bags

Pros & Cons of Composite Decking

Before you make a commitment, weigh the pros and cons of composites.

PROS:

Reduced maintenance: Forget about having to bleach and stain wood every other year. With the money you save by not using these coatings and cleaning materials, you can recoup the higher cost of composites in about five years.

Long life: Composites don’t rot or attract termites, they can’t warp or check, and you can go barefoot without fear of splinters.

Minimal fading: All composites turn a slightly lighter shade after the first two or three months in the sun, then the fading stops. (Left to its own devices, wood inexorably turns gray.)

Longer boards: Up to 20 feet, which means fewer end joints.

High recycled content: Every 10 square feet contains nearly 3,000 recycled plastic shopping bags and 1,100 one-gallon milk jugs.

CONS:

High initial cost: Low-end composites are priced about 30 percent higher than pressure-treated pine. High-end composites run about the same as ipe (ee-PAY), a hardwood decking harvested from tropical rain forests.
Easily scuffed: Moving furniture, frisky dogs, and gritty shoes will abrade new composites. Light scratches can’t be sanded out but do blend in over time.

Prone to staining: The wood fibers are easily stained by food and grease. And the hardwood in many mixes can create uneven brownish tannin stains early on when wet, but they typically disappear over time.

Hot underfoot: Like dark hardwoods, dark composites heat up as they bake in the sun. Lighter-colored and deeper-grooved boards are more barefoot-friendly.

Doesn’t really look like wood: Some boards do a better job at mimicking wood than others, but a close look or touch gives them away.

Maintenance

Composites have few maintenance needs, so you’ll have plenty of time to take care of the ones that do crop up.

Clogs: Sweep or blow away any debris between the boards so that water can run off freely.

Food stains: Fast action is the best defense. Use a degreaser such as Dawn dish soap on oily spots, and bleach and hot water on fruit and wine stains. Placing mats around the barbecue is a good preventative measure.

Tannin stains: Scrub with cleaners that contain oxalic acid.

Gouges: Superficial scuff marks blend in over time, but any board that has deep scratches or melt marks will have to be replaced.

Mildew stains: Add some dish soap to a 50-50 mix of oxygen bleach and hot water.

The future of wood composites

The ability of wood composites to be tailored to specific uses, together with their strength properties and affordability, makes them a viable solution to reducing the need for solid wood. They have been successfully applied in all forms of building, from small home projects to industrial construction work, and as technology surrounding their manufacture only advances, the future looks bright.

References:

  • https://www.thisoldhouse.com/decking/21018023/all-about-composite-decking
  • https://en.wikipedia.org/wiki/Composite_lumber#:~:text=Composite%20lumber%20is%20a%20material,%2C%20a%20wood%2Dplastic%20composite.
  • https://buildabroad.org/2017/02/22/wood-composite/
  • https://homeguides.sfgate.com/difference-between-wood-composite-veneer-laminate-100725.html