Can I stain my Deck when it gets cold out?   The short answer to that is Yes as long as the outdoor temp is 40 degrees or above when you are applying the stain.  It is ok if the temp drops below 40 degrees in the evening.  When staining your deck in colder temperatures, be sure to wipe off any excess material after 30 minutes.   Drying time will depend on sunlight and outdoor temp.

TWP Sets up after about 30 minutes, the oils on the surface are what take a little while to dry which is why you want to be sure to wipe any excess off in that 30 minute window.  If you need help feel free to ask or give us a call!

Maintenance with TWP Stain is quite simple for surfaces previously treated with TWP Stain.  There is no need to strip off the old stain or to sand the deck.  Follow these simple instructions to keep your deck maintained and looking new for years.

Signs that your deck needs to be treated again with TWP.
Typically, your deck should be treated with a maintenance coat about every three years for surfaces that you walk on and every 5 to seven years for other surfaces such as rails and spindles.  Here are some signs that show it is time to re treat your deck:
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1. The color that you applied may become lighter.
2. Mold (Black)  or Algae (Green) may appear on the surface.
3. Water no longer beads on the surface.
4. Stain color wears off where there is a lot of foot traffic.

Preparing your deck for a maintenance coat of TWP Stain.
A light cleaning of the surface is all you need to do to re-apply TWP Stain.  There is no need to strip the old stain off or for any sanding.  To clean the deck, you can create a cleaning solution using the formula below or purchase our Deck Wash Pro product.

When cleaning we recommend using a 5 Gallon Bucket, Scrub Brush and a garden house.  If want you can use a pressure washer but you will want to keep the pressure down and the tip at least a foot away from the surface.  You are not trying to remove stain – just the dirt and mold that has built up over the past few years.

Cleaning Solution Mixture
5 Gallon Bucket – 75% Water and 25% Bleach with a half teaspoon of dishwashing detergent (liquid).  Wet your deck then using your scrub brush work the cleaning solution over the boards and rinse thoroughly with your garden hose or pressure washer.

TWP Maintenance Coat
Apply your TWP Stain as usual – for application instructions go to sealandprotect.com/application

TWP Mildew Sealer is a professional strength, easy to apply formula protecting against mildew in the following ways:

TWP Mildew Sealer is a clear drying sealer for chronically mildew prone painted surfaces which contains a preservative to prevent mold and mildew from attacking the surface of the sealer.

When applied over existing mildew, it provides a clean mildew free surface which helps to prolong the life of the latex finish.

TWP Mildew Sealer has excellent adhesion over moderately chalky surfaces and serves as an excellent bonding primer to reduce peeling.  The finish dries clear and quickly.

This is an ideal product where mildew surface defacement and finish film service life and appearance is important.  TWP Mildew Sealer must be finish coated with a high quality 100% acrylic latex finish.

TWP Mildew Sealer is good for use on previously painted surfaces and on new wood.  Just be sure it is finish coated with a high quality 100% acrylic latex finish.

This product is not to be used with TWP Stain Products.  It is meant for painted surfaces only.

Wood Siding
Keeping the "Natural Look" on Wood Siding
By Al Rubin ­ Pages 24-26/Journal of Light Construction ­ April 1992

In siding as in much else, the "natural look" is in vogue these days, with many customers wanting to leave their cedar or redwood siding unpainted and unstained. Most customers, however, want their houses to retain this natural took, with all its honey-toned brightness, and without the natural graying that untreated wood sidings take on when exposed to sun and weather. In days past, heartwood from cedar and redwood had enough natural preservatives to discourage, or at least slow, this aging process. But quality wood is increasingly rare.

Today, keeping the natural look requires some rather unnatural finishes to block or slow the action of moisture and sun. These products have become an increasingly important part of the paint and stain market. Though no clear or lightly-tinted finish will last as long as a heavily pigmented stain or paint, the best of them preserve that new-wood look for up to five years if applied correctly on good wood. The wrong finish applied poorly, however, is little better than no finish at all.

Wood turns gray because of two factors: the degradation by sun and water of the outermost layer of wood cells, which turn gray as their natural oils dry out; and the growth of tiny mildew spores on the wood's surface. Preventing this graying while retaining a natural look is the job of the current generation of clear and natural-tone tinted finishes. These coatings are formulated to protect the wood from graying with a combination of replenishing oils (which are essentially the same as in any other oil-based stain) and what the industry calls "UV blockers."

Clear Vs. Tinted
Clear finishes, having no pigment, attempt to block the sun's effect solely with UV blockers. These come in two basic types, either or both of which might be present in a given clear finish. (Manufacturers are fairly secretive about their formulas.) One type is an inorganic "reflector," made of transparent iron-oxide pigments that let visible light through, but which block UV light. The other type is the "absorber," composed of organic chemicals that protect the wood by absorbing UV rays.

These UV blockers are similar to skin sunscreens: They block and/or absorb the suns UV rays, but only for a while. Given exposure to sun and water, they eventually wear off (in the case of the "reflecting" clear pigments) or wear out (in the case of UV absorbers). This usually happens within a year or two. At that point, they must be replenished if the skin of the building is to remain protected. If they're not, the siding gets its version of sunburn - it turns gray.

A tinted finish - that is, one lightly pigmented to a wood tone such as cedar or redwood - is, by definition, not the same thing as a clear finish. Yet many times, a house spec'd for a clear finish might be better created with a cedar-tinted or redwood-tinted finish. Most of the time, a clear finish is spec'd when a client or builder wants to preserve and enhance the natural tones of new cedar or redwood siding; that is, they want the siding to retain its original honey or reddish tone and not turn gray. But I usually recommend a tinted finish because, while a tinted finish won't substantially change the appearance of the wood (Other than heightening the grain and deepening the tones), its pigments will protect the wood longer than a clear finish will - perhaps for three to five years instead of one to two. For these reasons I usually recommend a tinted finish over a clear finish when the owner wants to retain that new-world look.

However, there are cases where a clear finish is called for: When the client wants already-weathered siding to retain its gray or pewter tones or when an owner has new siding treated to turn the wood gray, for a weathered appearance. In some cases, the siding will have taken on some other color tone, either through age or previous stain, that the owner likes and wants to preserve.

In all these cases, a clear finish can preserve the wood's appearance while helping to protect it from further weathering or degradation. But it will need to be reapplied every year or two to remain effective.

Finding a Good Product
Whether you want clear or tinted, you'll find many finishes to choose from. Over the last 20 years, I've used many of the available products. I've found quite a few clear finishes that would protect siding for a year or so, and many tinted finishes that would work for two to three years. But over the years I've settled on two products that roughly double these figures and outperform anything else I've tried: Amteco's Total Wood Preservative (TWP), and Flood's Clear Wood Finish, or CVIF.

These products have several important similarities and a few differences. They are both oil-based products with paraffin added for water protection. Both come in clear and wood-tone tinted versions. In both cases, the clear finishes will turn wood slightly darker an application; but that will lighten up in a few days or weeks to return to the original new-wood tone. In the tinted versions, the pigments add depth and color to the grain of the wood, and they may even out variations in the natural wood's tone. But they won't change the wood's basic color.

In general, I prefer Amteco's products. I've used them heavily for 12 years now, and I like their easy application, consistency, and longevity. However, I have used Flood's from time to time, and have found they work well too, though in my experience they haven't lasted quite as long as Amteco's products. But they are close competitors, so I think it's appropriate to describe both here.

Amteco
Amteco's clear and tinted products are known in the trade as TWP - the clear finishes as TWP 100, the tinted versions (redwood and cedar) as TWP 101.

TWP stands for different things in the older, non-VOC-compliant and newer, compliant versions. The non-compliant version - still available in places without VOC regulations - is known as Total Wood Preservative. The compliant version, available mainly in regulated areas, is called Total Wood Protectant.

I've been using the older, non-VOC-compliant formulas for 12 years. In the past year and a half, I've switched mainly to the new compliant versions. These have a higher solids content than the older formula (about 90%) and so take longer to dry. But since they soak into the wood, this doesn't pose a serious problem; if anything, it gives you a little more leeway when trying to get a wet-on-wet application.

Obviously I can't say for certain that the new versions will last as long as the old versions - up to two years for the clear finishes, four to five for the tinted. But I've used a similar Amteco product - Shake and Shingle Sealant - in a VOC-compliant version for about four years, and it has performed quite well. In addition, accelerated aging tests at the University of Texas Forest Products Lab in Lufkin, Texas, suggest that Amteco's compliant TWP products should last as long as their others. And the jobs I've done so far have performed well. I expect these compliant versions to retain the same quality the earlier versions have.

Amteco's clear TWP 100 lasts as long as any clear finish I've used. With a single coat on most surfaces and a double coat on southern or southwestern surfaces, it can last up to two years before graying starts. (Amteco's basic recommendation is for one coat; but with all these products, we've found a second coat increases longevity.) After that, exposed wood will begin to gray, turning completely gray by the end of the third year. Like other Amteco products, TWP 100 applies easily and doesn't tend to "lap" - that is, reasonable variations in spraying thickness don't produce uneven tones.

Amteco's tinted finishes have this same forgiving character. Several years ago, a sudden rainstorm forced one of my crews to abruptly stop work while coating the gable end of a two-story building with TWP 101 Cedar-tone. This left both horizontal and vertical lines between the raw wood and the treated section. When the crew resumed work several days later, they overlapped the new work slightly into the old, finished the gable end, and crossed their fingers. When the new work dried, you couldn't find the division between the new and the old.

We've found Amteco's tinted products to be highly durable. Generally, TWP 101 applied at 150 square feet per gallon (one coat on most surfaces, two on southern exposures) will last about 36 to 40 months; sometime in the fourth year, the wood will begin to turn brownish. At this point, a cleaning with a bleach solution will remove mildew and dirt, and another coat of TWP will reestablish that new-wood look for another three to four years.

TWP's tinted products, by the way, can also be used for roof and deck surfaces, on which it will generally last for about two to three years. We experimented on a cedar shake roof here in St. Louis. (With hot summers and cold winters, St. Louis roof and siding jobs take a beating.) We applied a double coat of TWP 101, with each coat sprayed at a heavy rate of 100 square feet per gallon. That finish job lasted eight years before turning really gray, and helped to extend the life of the shake roof.

Click here to view TWP Stain colors and to buy online.

Flood's
Flood's CWF (P.O. Box 399, Hudson, OH 44236-0399; 800/321-3444) also comes in both VOC-compliant and non-VOC-compliant versions; the compliant version, out for about a year and a half now, is labeled CWF/UV. I've found that CWFs tinted finishes wear out about a year earlier than Amteco's - lasting about three to four years. But they, too, are easy to recoat, requiring little prep as long as the client doesn't wait too long. You can tell it's time to recoat when the siding shows the usual graying. With Flood's you might also see some light flakes on the surface that can easily be rubbed off with your hand.

You can clean the siding of both mildew mid the CWF flakes by spraying with a bleach solution. At that point you can repeat your original application, except that, as mentioned above, you probably need only one coat (at 150 sq.ft./gal) rather than the two coats Flood's recommends for a first application. You would, however, need to apply two coats if the siding has turned completely gray. If you're applying only one coat of CWF, you must take care to produce an even coating; if you lap the brush or spray strokes too heavily, you can produce the uneven tone called "lapping." If this happens, however, a second coat will usually make it disappear.

Application Fundamentals
Most general contractors sub out their finishes. But for those who do their own, or who do the occasional small job, a few application basics will help the job go smoothly - or help you keep tabs on the sub.

Open the grain. Any penetrating finish works best if it's applied to wood that is relatively free of moisture and excess oils and extractives, so that the finish can soak in. Old wood is almost always this way, but new wood often needs help. One approach is to let new wood siding age in the sun and rain. But that degrades the wood's outer layer and grays it. A quicker way, and one that doesn't degrade the wood, is to spray the new siding with a solution of household bleach - one cup to a gallon of water - and then power rime. The bleach removes any surface oil, extractives, and mill glaze, and the wetting and drying helps to open the wood's grain. Make sure you wait at least two days after rinsing (or any rain) before applying the finish so the wood can dry. Sun or wind, of course, can accelerate this schedule a bit.
No discussion of opening grain would be complete without a reference to the perennial question of whether the siding should be rough-side out or smooth-side out. Like any penetrating finish, a clear or tinted finish works best if applied to the rough side of siding. The more open grain of the rough side absorbs more of the finish, giving the siding more protection. Smooth sides should be reserved for paint jobs.

What to spray it with. The easiest way to apply these finishes is with sprayers. I use sprayers from the Wagner 8000 to 8500 series (Wagner Spray Tech, 1770 Fernbrook Ln., Plymouth, MN 55447-4663; 612/553-0759). These are gas-powered, airless, diaphragm-type sprayers capable of delivering constant pressure up to 2,500 pounds per square inch. We tend to spray around 800 psi, which delivers at a good rate but prevents overspraying.

These Wagner sprayers can pump from 1/2 to 1 1/2 gallons per minute, supplying up to three hoses. We generally leave the pump on a trailer putting either a 200-gallon or 500-gallon tank, and run long hoses from there. We use about 200 feet of hose per gun. Each gun has a Graco Reverse-A-Clean IV 517 nozzle, which has a .017-inch opening and a 10-inch fan to spread the finish.

This, of course, is expensive equipment, appropriate only for big operations like ours. Wagner (and other companies) also sell smaller, electric airless units, complete with guns and one-to five-gallon hoppers, for under $500. You might consider buying or renting one. (Bleach wilt destroy these pumps, however, so on a small job just use a garden-type pump sprayer for bleach.)

How many times to spray? On most jobs, I apply one coat on the whole house and add a second coat to southern and southwestern exposures.
We generally let any side we're going to recoat soak up the first coat for an hour or two before hitting it with the second. My feeling is that you might get a little extra wear if you waited until the next day for the second coat. But those extra few months aren't worth the considerable-cost of setting up and taking down everything a second time.

Sometimes more coats are appropriate. For instance, in sun-intensive places, where wood takes an extra beating, a second coat all over, and a third on the most exposed areas, can significantly increase the value of the job, particularly if you can do them all in one day, as is often possible.
You can also add a third coat to the southern exposure when the budget is a little loose; for the extra money, the owners buy some extra time - usually a couple of years - before they must again have their property invaded by a spray crew.

How to spray. For the first coat, we generally spray clear and tinted finishes at a rate of 150 square feet per gallon. On the second coat, we go slightly lighter, at 200 square feet per gallon. If a budget is extra tight, we might make our second southern, exposure coat just a mist coat to save materials.

Spray starting at the top of the wall, and work your way down in long side-to-side sweeps. Spray just enough to saturate the wall - enough, in other words, so that the preservative slightly runs down the wall, or "curtains", as the trade calls it.

You can also pace yourself if you know the delivery rate of your sprayer and the area of the walls you're covering: If you're spraying a gallon a minute, for instance, you'll want to take about one minute to cover a 15-foot stretch of 10-foot- high wall.

In general, you want to spray from about a foot away, making horizontal passes with the tip turned vertically to the siding. A 3-foot pole is the best general-use extension pole; it will keep you out of the spray but still reach the eaves. Some pros use a 6-foot pole, which can be a little unwieldy and takes some practice.

How long should I wait before staining my pressure treated deck?

Pressure treatment is a process that forces chemical preservatives into the wood. Wood is placed inside a closed cylinder, then vacuum and pressure are applied to force the preservatives into the wood. The preservatives help protect the wood from attack by termites, other insects, and fungal decay.

Some pressure treated lumber is already dried and ready to stain.  Dry treated wood is ideal because you can confidently stain it right away. To recognize it, look for a tag or stamp that says KDAT (kiln-dried after treatment) or ADAT (air-dried after treatment).

Allow treated wood to dry thoroughly before staining or painting.  It is recommended that you allow the wood to dry for at least 6 months prior to staining.  Test dryness by sprinkling the wood's surface with water. If the water beads up, the wood is too wet and you must wait before applying a finish. If the water soaks into the wood, then it's dry and ready for stain.

Over time, most treated lumber will shrink slightly across its width as it dries out. Take this small amount of shrinkage into account when laying decking or fence boards.  After being outdoors for six to 12 months, treated lumber will develop cracks, called "checks," along the surface of each board. These hairline cracks are a normal part of the drying process.

TWP Stain is a penetrating stain which means that it needs to penetrate the wood in order to provide protection, which is why you need to wait for the wood to dry thoroughly prior to staining.   

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Many customers ask if they can tint TWP stain to achieve a different color.  There are two ways to achieve custom colors with TWP Stain.

Mixing within the same series

You can mix colors within the same series to achieve the color you are looking for.  For example, if you are looking for a lighter version of the standard color you can mix up to 25% clear from the same series to keep the UV protection and lighten the stain.

Remember you cannot mix between series - colors can only be blended together from the same series.

Tinting TWP Stain

You can NOT tint TWP 100, TWP 1500, TWP 300 or Water Series stains.  However, we do sell tints for the TWP 200 Series stain.  Tints are available in the following colors:  Black, Yellow, Green, Gray, Red.  You can use the tints with any of the TWP 200 Series Stain Colors.  Tinting the clear does not provide the best protection as there are no binders in the clear to keep the colorant.

We sell the 200 Series Stain Tint in Quart cans - a little bit goes a long way.  Tinting TWP 200 Stain is only recommended for the experienced user. 

To purchase tints or to ask questions please call us at 404.865.1299

Click HERE to view all TWP Stain Colors

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"Question:  I have a house in the Colorado Mountains that I intend to re-side with rough cedar.  I can not tell from your descriptions why the TWP 100 product will not work as well as the TWP 1500."

Answer:  Both TWP 1500 and TWP 100 will provide the same protections. 
TWP 100 Stain has a V.O.C. of 550 grams/liter. Certain states now require lower V.O.C. limits in wood preservatives (350 gram/liter). TWP 1500 Stain is the same base formulation as TWP 100 Series with minor formulation changes to comply with the state regulations.

The same color choices come in both series with the exception of the Black Walnut (1500 series only) and the Cape Cod & Prairie Gray (100 Series Only)

TWP 1500 Series will go on over the 100 Series as long as it has been a year since you last stained the deck. 

TWP 100 Stain can not be shipped to CA, CT, DC, DE, IL, IN, ME, MA, MD, NH, NJ, NY, OH, PA, RI, VT, VA and CANADA due to VOC regulations.

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Even though pressure treated yellow pine, western red cedar and redwood lumber are extremely durable materials, their useful lives depend upon their environment. Left unprotected, these woods suffer photo degradation by ultraviolet light (sunlight); leaching (water absorption into wood components); hydrolysis (as in acid rain attack); shrinking and swelling caused by water absorption into and evaporation from the wood; and finally, discoloration and degradation by decay promoting micro-organisms.

Photo degradation By Sunlight
Solar radiation is the most damaging component of the outdoor environment affecting every surface. The decomposition of the wood is signified by the gray color that appears. This fiber loss occurs due to the sunlight destroying the lignin, the so called "wood fiber glue". Rainwater washes away these "loose" wood fibers and decomposed lignin exposing fresh wood to start the process all over. In addition, microscopic cracks and splits develop, allowing deeper water penetration. This mechanism is very evident in exposed structures located in the southern states.

Moisture Degradation
The sun and rain cycle causes moisture fluctuations in the wood resulting in shrinking and swelling stresses. Deeper checks and splits develop from these stresses causing all wood to cup, warp, curl, split and check at an accelerated rate. This process is accentuated in Douglas Fir, Pine, Spruce and Hemlock, which experience greater dimensional changes than cedar or redwood, with moisture loss and absorption. Some of these dimensionally unstable species are common pressure-treated candidates. Osmose, Woman, Borates and CCA are common pressure-treat systems or chemical names. Therefore, protecting the wood fiber of pressure-treated lumber from rapid moisture absorption (fiber swelling) and moisture loss (wood shrinking) is crucial to preventing premature wood failure modes not associated with rot. Hence, maintaining long term water repellency of the wood is an imperative coating property.

Wood Destroying Fungi
The natural decay resistance for western red cedar and redwood is due to their heartwood chemical components, including the thujaplicins and a variety of phenolic compounds. The thujaplicins contribute to the decay resistance of redwood and cedar. The phenolic compounds and resins give cedar its water repellency and lubricity (slippery surface). Both the phenolics and thujaplicins are water soluble and accordingly lost during use. As these compounds are lost, wood destroying fungi colonies may develop in the wood. This type of attack is characterized by the wood edges becoming soft and spongy, stringy, pitted, cracked and crumbly. Fallen leaves, continuously shaded areas, dirt accumulation, and constant contact with moisture (sprinklers and a heavy dew factor) can encourage fungi growth. This type of attack is characteristic of high moisture areas such as the Pacific Northwest and Southeast United States.

Older Trees are Better
Another important consideration is that new cedar and redwood lumber is being processed from younger, less decay resistant trees since the old, high natural preservative content logs are becoming harder to find. The life expectancy therefore is shortened. These factors, coupled with an increased awareness of various environmental issues in recent years to protect old growth timber, are further reducing the supply for high quality wood. This supply shortage represents a price increase of 50% to 150% on prices for cedar & redwood and it is affecting southern yellow pine also. This leads to the obvious conclusion that taking care of aged, older wood has become an economic necessity on your house.

The Like New Restoration Process For Wood
Fortunately, wood can be restored most cases to that "Like New" look. However, the transformation process is tedious involving repair, mold and mildew removal, wood surface preparation (removing the gray) and coating application. The toughest portion of the process, in terms of time and the cost, is the wood surface preparation procedures - including mold and mildew removal. The most important single decision in the process is which protective coating to use. If the right material is selected, that rich gorgeous restored look can be easily maintained for years - per the latest testing results (shorter in high traffic areas). If the wrong material is selected, the entire restoration process may need to be repeated in as little as 3-6 months to maintain that desired look.

Organic Growth Removal and High Pressure Water Washing
Mold and mildew are the dark gray or black growth we see on wood. All organic growth must be completely removed through surface stripping, high pressure water washing or a combination of the two. The restoration professionals generally use a combination of the two to more efficiently remove the top layer of weathered wood (gray wood) and organic growth at the same time. The process involves application of a diluted stripper (best) or special wood bleach) followed by high pressure water washing.

- Cautions -
Plant and vegetation protection is important, particularly when using bleach or oxalic acid. Oxalic acid's main industrial use is to etch metal. It has a strong odor and can cause repetitive coughing to those close to the applied material. USE A RESPIRATOR. Packaged properly with special surfactants and detergents, oxalic acid based products can be much safer and easier to use than bleach. High pressure water washers can be damaging to property and dangerous to the operator. BE CAREFUL!
 
Selecting a Natural Finish
Now that we have discussed how to get your deck or patio back to that "like new" look, we must consider how to maintain that "like new" look---preferably for a long time. The bad news is that most natural finish materials look great initially but last for only a few months as evidenced by wood "graying" or loss of water repellency. Most semi-transparent stains and varnishes (known as film formers) do not fair much better, with cracking and peeling being a major problem. It appears that the more highly advertised the product, the shorter it's life expectancy. Now for the good news. In this section, we will discuss the latest Texas Forest Products Lab (part of the Texas A&M University system) longevity testing and how to select the easiest systems to maintain. These results are taken from standardized roofing coating test which are the closest applicable standardized tests for the simulation of horizontal deck applications. We will elaborate on why penetrating oil-base systems are superior to water-borne systems, film formers and varnishes from the performance and "maintainability" standpoints.

The Toughest Weathering Tests
What makes the Texas Forestry's work so significant for those living in Southern and Southwestern states is that the natural weathering tests are conducted at a similar global latitude to ours. This closely duplicates the tortuous sun exposure we experience in Southern states, plus adds the damaging impact of the extremely high Gulf Coast rainfall and humidity. Those in the Northern States can feel good about Texas Forestry's work since the additional sun exposure makes testing more rigorous than could be achieved in the Northern States. The most meaningful testing that the Texas Forest Service provides is natural weathering. They have proven that accelerated weathered testing for natural wood finishes has no direct bearing on actual field performance longevity. Natural wood finishes that have been exposed to what normally is translated to a 3-5 year exposure (standard 1000 hour test for paints) failed in less than 2 years when subjected to natural weathering exposures. Therefore, when companies talk about accelerated weathering as their only basis for performance or long warranties (and usually high prices with warranty backing), run the other way! Natural south facing exposure-testing for sun resistance and north-facing exposure for organic growth resistance are the only meaningful proven tests. Some new accelerated tests utilizing mirrors or black box exposure to magnify the sun's effects are showing promise but I am not aware of any standardized correlation's yet for these types of exposures.

Oil Versus Water-Borne Finishes
For wood, in most southern states, the sun is Public Enemy #1. The sun is directly responsible for the intense drying effects leading to cupping, curling, cracking, splitting and surface checking. Water-borne treatments do little to alter these natural processes, but some are effective at controlling mold and mildew. Therefore, oil-borne treatments are recommended since they replenish wood oils that have been oxidized by the sun or washed out by the rain. Proper high flash point parraffinic oils (the new industry standard) are not only oxidation resistant, but also do not contribute to wood flammability (a consideration mainly for wood roofs). Though somewhat more expensive, oil-borne treatments are recommended over water-borne materials because of their superior performance. Wood is the pipeline for nutrients. The wood fiber is basically a series of straws that shrink and grow with moisture loss and absorption. By absorbing oil, these straws tend to regain part of their original size which reduces internal wood stresses as well as the volume available to be occupied by water upon exposure to rain or any other moisture source.

Natural Finishes vs. Semi-transparent; Transparent vs. Clear
Most people prefer a natural wood finish (full grain character allow to show though without a painted look) to full body stains. By natural finishes we are referring to clear or transparent finishes. Semi-transparent or full body stains are "thinned" paints (lower in pigment and resins solids) utilizing inexpensive, standard paint pigments (colored particles). These standard paint pigments have a large particle size which, at least partially, hides the grain from view. On the positive side, these large pigment particles provide valuable sun protection for the wood and coating itself. Be sure to understand the difference between "transparent" and "clear" coatings. "Clear" means absence of color. Transparent coatings have a special type pigment that will not block one's view of the wood grain from which the name transparent is derived. These transparent-oxide pigments (trans-oxides) are expensive but when utilized in natural finishes provide the desired; an obstructed full view of the wood couple with the coating itself. The very small particle size "trans-oxides" appear to our eyes almost like "dyes" on the wood surface when used in routine concentrations. Neither manufacturers or the buying public can afford to place enough UV absorbers and light stabilizers in a "clear" material to provide adequate sun protection by themselves. The sun protection provided by pigments are as important to the longevity of the coating system as they are to the protection of the wood surface. Be informed that the true "clear" materials will allow the wood gray or age quicker as well as degradation of the coating itself will be accelerated over that experienced by trans- oxide pigmented systems. Pigmentation helps extends the life of the coating system resins (binder that holds everything together) By physically blocking the damaging UV rays from contact with substantial portions of the vulnerable resins. The benefits of pigmentation appear to increase as the sun exposure increases (in other words, pigmentation is more important in the southern states than the northern states). We always recommend pigmented systems for exterior use to maximize wood and coating system longevity.

Maintenance Considerations:

Film-Formers vs. Penetrating Finishes
The problems associated with materials that form a surface film is that they tend to crack and peel when failure occurs. That means that chemical stripping or sandblasting is necessary to restore the substrate to a true natural look for reapplication. This situation is generally true of varnishes and most semi-transparent or full-body stains. The look of varnish is exceptional, but most of the varnish systems that I am aware of fail by cracking and peeling due to wood expanding and contracting. Once that starts, moisture seeps behind the film causing water staining and lifting of the coating off the wood and creating the ideal conditions for mildew or mold growth. The only viable solution to remove the water stains and unsightly black and gray growth is to chemically strip or sand blast/pressure wash the varnish (expensive). Then start over with an application of a fully penetrating, transparent natural wood finish. Some people have tried to minimize out of pocket costs by painting over the peeling material BIG MISTAKE!! Within a couple of years, the peeling film former and trapped organic growth shows up as discolored, peeling paint. Now the size of the problem is much larger and the cost of the "fix" is much greater.
 
Does Preservative "Mean Better"?
Some products are called preservatives. The word "preservative" carries the connotations that a material named should be the best, long lasting product available. Unfortunately, this simply is not true. The word preservative legally refers to an EPA registered component in the product which will affect fungus growth. If the claim is made that a product imparts fungus resistance into the wood structure itself, the complete product formula must be registered as a preservative. This "preservative" registration does not address water repellency, mildew resistance (different from fungus), UV resistance, longevity of the system or anything else of importance. The top-rated roof and deck system is not a registered preservative because it contains only a registered mildewcide and makes no claims about preservative properties. Yet by effectively controlling ultra-violet light and moisture loss and absorption for many years, it out performs most "registered preservatives" by a very wide margin. Therefore, be aware that the word "preservative" by itself does not mean much in today's world of high performance coatings. But, preservatives can be very important components of some systems---but it is only one component.

The Best Solution: Penetrating Oil-Based Finishes
To date, the best solution to the exterior wood finish dilemma is to use penetrating oil-based finishes that do not form surface films, and hence, do not pose serious lifting or peeling problems when the time to reapply is apparent. The resins (binders) for these systems set-up in the wood pores and do not form continuous films in classical sense.  Maintenance then becomes as simple as cleaning the dirt from the surface, allowing the wood to dry and reapplying another coat.

Much cheaper, much easier, much faster than stripping or scrapping off old, peeling films. For restoration, the best of these systems contain a high percentage of free oil to restore the wood's moisture content as well as provide additional water repellency for the wood. The top systems in this category range in solids content from 60-97% (solids are defined as that portion of the system that will not evaporate upon use, or in other words, the important stuff that works). Generally, the higher the solid content the better. In contrast, many of the common name brand sealers on the market contain solids that range from 2-15% -very low. Besides being somewhat more expensive (for obvious reasons), The only drawbacks of these ultra-high performance systems are that they can take up to a few days to dry (particularly in cool weather) and soil somewhat more easy (routine rinsing and /or cleaning with dishwasher soap is a major help here). But the long-term protection and color maintenance is by far the best that is currently available for any type natural wood application.

The Natural Deck Coating Dilemma
The combination of foot traffic, pets, kids, sun, dirt build up and standing water (occurs every day if you have nightly dew) are very hard on deck coatings. Most of these natural finishes are designed to provide minimal blockage of the wood grain (essentially look as if they are not present) yet provide protection from everything. Long term color maintenance on decks is just not feasible with just one single application per deck. For roofs and sidewalls, 5 years of color maintenance in the southern states are capable of that life expectancy. Only a couple systems are capable of the life expectancy per the Texas Forest Service work.
 
The Expected Life of "The Best" for Decks
It is anticipated that the natural wood finishes with a high solids content when applied to fully exposed south or west facing decks will provided color maintenance for 2 to 3 years on aged wood in the southern states. These same systems generally provide longer term color maintenance as the sun exposure lessens or as one moves to a more northern climate. On new wood, a light coat should be applied to the wood to act as a stabilizer. This prevents the wood from splitting and checking due to moisture loss from drying and to get better penetration due to mill glazing. A reapplication of material and a light cleaning may be required after one year providing the wood with a penetrating finish.
 
Warranties, Do They Mean Anything?
I have seen people offering products for sale with warranties up to 30 years from purchase date. I have to laugh since we know there are only a few products that will last even 5 years on sidewalls and roof applications. These impossible warranties are offered by marketing people who believe they can sell anything - and they are usually right - until the market becomes wise to the misleading product performance. Normally the fine print says that 4 coats must be applied over 60 days and inspected by a company inspector or a power washing must be done every 6 months. One company offering a 25-year warranty required $1.20 to 1.50/sq. ft. be spent for coating material alone. The point of this discussion is to make you cautious when buying a natural wood finish and not fall for something that is too good to be true, because it probably is.
 
Important Points to Consider

1. Finish must contain resins (plastic binders) to minimize uneven color loss and streaking. This problem can be particularly true of some water-borne treatments. Pure oils are always subject to water wash-out or absorption by rain or dew unless protected by a resin barrier.
2. Make sure the product will "bead" water for several minutes - much like water beads on the hood of a freshly waxed car. The water repellency feature will minimize water penetration into the wood and reduce subsequent wood damage. When water hold-out disappears, it is time for another coat.
3. Paraffinic oils generally have a very low odor compared to their naphthenic counterparts. This can be important in high density apartment a condominium complexes or for persons with known sinus conditions, chronic allergies or other known health conditions. The napthenic oils (referred to as roof or floor oils) commonly used in inexpensive siding and roof treatments generally degrade in 9-18 months based on Forest Products Laboratory work. Paraffins will last 3-5 times longer under the same conditions.
4. Flammability test work (conducted by the Forest Products Lab on high flash point paraffinic oils) has shown that these materials have no effect on the flash point of the wood tested. This flammability work was comprehensive in that testing was conducted on fire retarded wood (cedar shakes), aged wood and freshly cut (green) wood with the same results.
5. Material must contain mildew and mold inhibitors, particularly in humid environments or in the presence of large amounts of water.
6. Linseed oil based products are not recommended for this particular microclimate. Linseed oil and other natural oils have some very good finish properties but contain glycerin and other sugars. To mold and mildew these act as a food source. Remember, natural oils are the lifeline of nutrients in trees or plants, and these plant nutrients will still support life - this is what we are trying to prevent from happening with your wood.
7. Pentachorophenol and mercury are strong enough to do the job but are presently unacceptable for the environment.

 
Recommended Products
Based on Texas Forest Products Lab testing, the following products are recommended for homeowners based on availability, price and excellent performance.

1. TWP Stain (full range of natural wood tone selections & grays) 
2. Natural Seal Clear X-100
3. Cunapsol 1