Restoration
 |
|
 |
 |
 |
| |
|||||
Restoration
|
|||||
|
|
This page provides the interested reader in some to the technical aspects of Wood Restoration. If you have any questions about the information please contact us either by phone or by email listed under Contact Us.
1. General Information on Wood Preservation.
Whether you have an old deck or brand new one, protecting it from the harsh elements of weather it necessary to maintain its appearance and structural integrity. Figure 1, shows what can happen to unprotected wood. Remember deterioration starts the minute the wood is exposed to the weather.
Most wood structures constructed in the United States have been made with pressure treated wood. There are advantages and disadvantages of using pressure treated wood. First the pressure treatment does prevent rot and termite infestation however the process used to treat the wood makes it more porous and susceptible to moisture damage. Therefore, some kind of protection is also needed to not only prevent deterioration from weather but also to seal the wood.
Second, as most consumers know, pressure treated lumber contains Chromate Copper Arsenate (CCA). In other words, pressure treated wood contacts arsenic. A voluntary decision by industry to stop producing wood that contains arsenic by December 31, 2003 was announced by the Environmental Protection Agency (EPA) on February 12, 2002. This will affect virtually all residential uses of wood treated by CCA including wood used in play-structures, decks, picnic tables, landscaping timbers, residential fencing, patios and walkways/boardwalks. As of January 1, 2004, the EPA will not allow CCA products to be used for wood intended for any of these residential uses. The EPA has concluded that there is not an unreasonable risk to the public from products with CAA. Therefore, to prevent exposure to CAA it makes it desirable for all wooden structures to be protected.
If you thought using Redwood and Cedar will prevent some of the problems with pressure treated wood, protection is still needed for these products. Redwood and Cedar used in today’s construction of wood products are not as resistant to the effects of weathering. This is because the wood is from younger, second growth trees which have a higher sapwood content.
If you do not seal your wood product, the unprotected wood absorbs rain, dew, and melting snow then the sun dries it out causing it to shrink. This cycle eventually causes the wood to warp, split, and crack generally shorten the life of the wood. Figure 1, below shows the potential problems that can develop. Not only is it important to protect your wood, it must be properly cleaned to remove the graying, dirt, mold and mildew. This an important part of protecting your investment. Wood needs at least 24 hours to dry after washing or being wet before applying sealant, and can be sealed the day after that, provided that the day after the sealant is applied there is another dry day. Arnold Powerwash uses a moisture meter to be sure the wood has the appropriate low moisture content prior to being sealed.
There are several differences between a Wood Preserving Finish and a Water Repellent/Proofing Sealers. First is the amount of EPA approved and registered pesticides (mildewcides and fungicides). One important fact to remember is although both are very similar in appearance, if any pesticide is present to preserve the wood, it most be registered. Once registered a manufactures can use the words “Wood Preserving”. Some common pesticides used in these products which provide decay resistance to wood include:3-iodo-2propynl butyl carbamate, zinc naphthenate, copper naphthenate, bis (tributyltin) oxide (TBTO) with N-tricholoromethylthio phthalimide and copper-8-hydroxyquinolate.
Second, Wood Preserving Finishes contain not only a preservative and wax, but resin and solvent, as well. Wax reduces the absorption of liquid water by wood and the preservative prevents wood from darkening by inhibiting the growth of mildew and decay organisms. However, without special ultraviolet radiation absorbers, Wood Preserving Finishes will not protect the wood surface from the sun’s ultraviolet rays. The resulting wood degradation causes the release of wood fibers, exposing underlying, unprotected wood fibers, which turn gray and then black from fungi attack. In addition, Wood Preserving Finishes generally contain less than 20% binder or resin. However with Water Repellent/Proofing Sealers, the wax in the product quickly breaks down on the surfaces and the water beading properties vanish. Depending on exposure, the life expectancy of sealers can range from six months to one year.
Using a Water Repellent/Proofing Sealer, can cause the water to “beads up” but sometimes the wood starts turning gray and is splintering. What the water beading indicates is a water repellent additive in your product. Unfortunately, it takes more than surface water repellency to protect your deck from the elements. To really do the job, you will need to use a product that penetrates the wood cells and encapsulates the wood fibers with a protective resin. Choose a product that will provide your deck with deep – penetrating protection from the damaging effects of the sun’s ultraviolet rays, as well as from rain and snow. Also, look for products which provide mildew resistance.
4. Solid, Semi-Transparent or Semi, and Clear Finishes.
When looking at products to use one will notice “Solid,” “Semi-Transparent” and “Clear.” The product you use is a matter of personal preference. All stains differ from paint in that they provide color yet, allow the wood’s character to show. A “solid” product is the most opaque and allows texture, but little grain detail is seen. A “semi-transparent” product allows some grain to be seen and a “clear” shows the most grain. Keep in mind that the more transparent the product, the more its color will be affected by the underlying wood; so variations in wood color will be more obvious with transparent products, as will any natural blemishes such as knots and tannin. Also, opaque products usually last longer because they block out a greater proportion of damaging, ultraviolet rays.
5. Wood Characteristics Affecting Coating.
Coatings fall into two categories. Continuous film coatings are primers, paints, heavy bodied and solid color stains that form a solid, unbroken film over the surface. Semi-penetrating stains, the second category, penetrate the surface of the wood to a great extent resulting in very little surface film. One, or both, or neither of these coating types, depending on their characteristics and how they are manufactured, may success-fully coat wood products. Density (weight), presence of early wood or late wood, texture (cell structure), and the extent of extractives including water-soluble color, pitch and oil give wood its character. Generally, higher density woods (hardwoods) are less suitable for exterior use than less dense softwoods such as cedar and redwood. Manufacturing and grading of wood products determine suitability for accepting coatings. Surface textures, knots or other defects, and moisture content greatly affect coating. How the product is cut from the log often dictates what type of coating can be used successfully on the product. Most standard lumber grades contain a high percentage of flat grain, whereas, premium grades are predominately edge grain. Flat grain areas tend to swell and shrink more and are relatively unstable and will not hold continuous film coatings as well as the more stable edge grain surfaces.
Yes, anyone can restore wood however; only a true professional can restore exterior wood correctly. To restore wood correctly is not a easy as it seems. Thus to restore exterior wood "correctly" it takes much more than a pressure washer and a water supply. A profession knows it takes more than a pressure washer, a little detergent, a water supply, and a Sealer to properly restore exterior wood products. The professional needs to be trained in to understand the differences in the types of wood; coatings; chemicals; procedures and methods; cleaners, strippers/neutralizers; pressure washing; rollers vs. brushes vs. sprayers; and maintenance coats. And, this is just the start. It takes experience and education to do the job properly. Know your contractor and his qualifications and characteristics. A reputable professional is able to prove they have knowledge of the trade by certifications affiliations to manufacturers, distributors, franchises, business or trade organizations. As a consumer, feel free to ask for a contractor’s background. A reputable power washer like Arnold Powerwash, is a current member of the Pressure Washers of North America (PWNA).
| ©2003 • Provided by Telijost Technologies | Home • Services • Restoration • FAQs • Contact Us | |
 |
|
