Exterior Stain & Seal 101: FAQ

1. Why should exterior wood be stained?
2. Why should exterior wood be stained instead of painted?
3. What makes the difference between a low-quality and a high-quality stain?
4. How long does stain last?
5. Does staining make financial sense?
6. What is the process to staining a fence?
7. What is the process to staining a deck?
8. What is a maintenance coat?
9. Can outdoor furniture and other exterior structures be stained?
10. Why is WGL&C a good company to hire for your staining project?

1) Why Should Exterior Wood Be Stained?

The outside elements of rain, sunshine, constant temperature fluctuations and the like will quickly turn anything made out of wood back into soil. There are three reasons to stain your deck or fence. 1) Protect it from the elements and increase it’s lifespan. Protecting your “investment” most accurately applies to expensive decks and buildings. For these more expensive structures, the primary reason to apply stain and seal really is to protect your investment, and aesthetics are secondary. 2) Reduce warping, cupping, twisting, and cracking. Notice I said it “reduces” warping, cupping, twisting, and cracking. It does not “stop” these things from happening. Wood is a natural product which like the honey badger, is going to do what it’s going to do. But stain and seal does tame this behavior slightly, by like 25%. 3) Aesthetics. For anything other than a large deck or building, this is actually the primary reason. Stain brings out and enriches the natural beauty of wood by highlighting the grain and giving it color and contrast. Otherwise, wood simply turns gray, fades, becomes unappealing, and returns back to dust from whence it came. Stain makes wood sleek and gorgeous and keeps it alive and vibrant for longer.

2) Why Should Exterior Wood Be Stained Instead Of Painted?

Wood in an outside environment is always better off stained rather than painted. There is one and only one scenario in which it could make sense to paint wood instead. That situation is when the wood in question is wood siding on a building that has a good roof. The framed wall of a building has less flex or movement than say a deck or a fence. It is also exposed to less direct sun and less intense temperature swings. And it is all vertical so it doesn’t collect water anywhere on it. In this situation it could make sense to paint instead of staining, if your aesthetic preference is for the look of paint.

Paints and low quality film forming stains are essentially composed of pigments, binders or glues, and oils or water based fluids which dry to the touch once the mineral spirits, paint thinner, or other solvents have evaporated out. This leaves you with a product that forms a thin film on the surface which in theory protects the wood. There is one problem though. In practice, the weather and the flex/movement of wood exposed to the elements will inevitably cause that thin film to begin cracking in short order. Water will find its way into these cracks and then the film traps that water in the wood making it such that the wood is exposed to water for longer periods of time than if the wood was never stained or painted at all. These cracks then increase in size and number, and the water continues it’s damage and the stain/paint will begin to fail everywhere, in particular on flat surfaces such as handrails and deck floors. The paint/stain will crack, chip, flake, and peel away. Then you might think, well it just needs another coat. But being film forming, follow up maintenance coats will be splotchy and uneven, and they will continue to crack and peel anyway given that the old coat beneath the maintenance coat has already began failing. The new stain will bind itself to the old stain, but the old stain was cracked and water had already broken the old stains bond to the wood, so it’ll go right on failing just as before.

The solution is a quality stain composed primarily of pigments and non-drying oils. The pigment, which gives the wood color, also protects the wood from the suns UV rays which are always busy degrading and breaking down all manner of organic matter such as wood. The non-drying oils are exactly as the name describes. They are oils which do not dry out. They are always fluid. These fluid oils soak deep into the wood filling in all the open space, within and between the cells. by doing so, water has no where to infiltrate. The oils are already occupying the available space in the wood. Since oil repels water, the water instead beads up and rolls off. Since there is no film barrier, there is no barrier that is subject to failure. So long as the wood is stained, then the wood is protected. Although, since the oils are always in motion, they do wash out overtime and need to be replenished.

4) How Long Does Stain Last?

So then, if high quality non-film-forming stains do not have a film that can crack and fail, how do they fail? Surely, they don’t last forever? Correct. Quality stains are composed of non-drying oils (which penetrate wood rather than cover wood up like paint). And these non-drying oils never dry out, which means they are always subject to movement. What happens is they essentially slowly get washed or eroded out of the wood. Wood expands and contracts with temperature swings, and along with heavy rain, the oils over time get washed out of the wood. So maintenance coats are required once per year to every few years depending on weathering conditions. The nice thing about maintenance coats with a quality stain is, since they are non-film forming, the oils really can’t be over-applied so maintenance coats always come out smooth and even just like the first time. The goal is to saturate the wood as much as possible, and once it’s soaked up as much stain as it can absorb, then the excess oils on the surface can be wiped off (in order to prevent an excess of pigment from puddling up and creating a dark spot on the surface). The result is maintenance coats always look great! Unlike film-forming stains which always produce uneven splotchy results with maintenance coats. Below is a general guide for how often maintenance coats will usually need to be re-applied. It is not an exact science, as it depends on the particulars of the weathering elements at each specific project location. For example the same deck in a south-facing sunny location is going to need a maintenance coat of stain sooner than a north facing deck in a shady location. A deck that resides under a massive tree which drips lots of sap onto the deck will likely need more regular cleaning than a deck with not trees overhead, which means the deck under the tree would also need to be re-stained more often because regular cleaning washes away the stain in the wood more quickly. A deck with lots of foot traffic will weather quicker than a deck with little foot traffic. A deck that is under a roof such as a screened in porch will last longer than the steps that extend out from that same deck but are not covered by a roof to shelter it from rain. Lastly, vertical surfaces always last longer than horizontal flat surfaces because they take less of a beating from the rain and the sun. Below is a chart for typical life-expectancies between maintenance coats. Just keep in mind, that the flats (deck floors and handrails) can wear out up to twice as fast as the verticals (deck spindles, posts, etc.) So although the typical deck can last up to 2 to 3 years between coats of semi-transparent stain, a deck that is in full sun all day every day, will more likely need a maintenance coat on the deck floor and handrails after just one year. It is not uncommon to re-stain just the deck floor and handrails every year or every 18 months, and then the whole deck every 2 or 3 years. Other factors can wear out a finish quicker as well, such as dogs that scratch up the deck floor with their toenails on a daily basis.

5) Does Staining Make Financial Sense?

This depends on the structure in question, and on how much you value the beauty of stained wood over un-finished wood. If we are talking about a log cabin, then yes it is worth it to keep it stained. It would be like asking if it makes financial sense to change the oil in a car. It does make financial sense no matter how someone feels about it. The cost of the initial investment is unquestionably more expensive than the cost of regular maintenance, such that the cost of regular maintenance makes financial sense. Now, let’s consider the other extreme, a planter box for a temporary raised garden bed. This hypothetical planter box has no interior liner to keep the soil off the lumber which means the box will rot out from the inside out, in just a few years no matter what you put on the outside of it, because it is in direct contact with moist soil all the time. Staining the outside isn’t going to slow that process down and it doesn’t make financial sense, unless you simply value the beauty of stained wood over unstained wood. It is purely a matter aesthetic preference. So now, on to the nitty-gritty. Decks and fences. Let’s take for example a regular 6ft privacy fence. A 300ft regular privacy fence might run you $12,000 to install. Staining that fence will run you $3,000 (or more) to wash and stain. Let’s say a maintenance coat of stain is applied every three years. That means every 12 years you will have spent the same amount of money as what it had cost to build the fence in the first place. In other words, had you instead done nothing and never stained the fence, then you would have saved enough money in maintenance costs to simply rebuild the entire thing. You can expect a typical fence to last 8 to 12 years unstained. The big question is, how long can a fence last if it is stained? And the answer to this question is a really really big, it depends. The variables are so great, that I can’t actually give an answer. But we can take a few hypotheticals to task. Let’s consider your ordinary fence installed by your ordinary fence company. Your ordinary fence company will usually set your posts in the ground, fill the hole up with some dirt in the bottom, then some concrete, and lastly a little more dirt on to top of the concrete which brings you to grade. In this situation, with heavy clay soils, you now have essentially a little cup which will hold water against the base of the post at and just below grade every time it rains. This will rot the post out in 8 to 12 years every time and stain is not going to help you in this scenario. Stained or unstained, your fence will last 8 to 12 years. Now lets consider the other end of the spectrum. This fence is a regular 6ft wooden privacy fence, except with one major difference. The posts are metal. In this situation, all of the wood components of the fence are above ground, and therefore stain can and will prolong the lifespan of the fence. The weak link in a fence is almost always the posts rotting out. This is even the case with metal posts as metal posts will eventually rust out. But they can be way longer lasting than wood. Let’s say the lifespan of a good metal post is 30 years. But the cost of good metal posts add $1,500 to your total fence cost. Your fence is now $13,500 to build instead of $12,000. An unstained fence with metal posts will still need to be rebuilt within 8 to 12 years as the pickets and rails will be rotting off by that time despite having metal posts. That means spending $3,000 every three years could prolong the lifespan of your fence. I’m not confident it could prolong it indefinitely like some would lead you to believe. But I bet it could get you close to the life span of your metal posts thereby maximizing the potential lifespan of your fence, so in this scenario you have two options. 1) not staining your fence, which means every 10 years you would rebuild the whole thing except the posts which would be reused. In this scenario the cost of having the fence in perpetuity is about $1,120 per year. That’s assuming a $13,500 initial build, and $10,000 rebuild every 10 years, and then we’re back to the beginning of the cycle every 30 years. Option 2) is $13,500 initial build, and $3,000 initial staining, and $3000 to wash and re-stain every 3 years, and then the cycle restarts every 30 years. The cost to have this fence in perpetuity is $1,450 per year. To recap, the cost of an ugly fence is $1,120 per year, and the cost of a pretty fence is $1,450 per year. In other words, the cost of a pretty fence is $330 per year more than the cost of an ugly fence. As a percentage, that’s about 29% more expensive for the pretty fence. Most people in the staining industry would lead you to believe that staining your fence saves you money. But I build fences and I stain fences, so I don’t care if I’m rebuilding a fence or re-staining a fence. Either way I’m staying busy and staying in business. So I’m here to tell you, when it comes to staining a fence, the cost of a pretty fence IS more expensive. Staining your fence is not “protecting your investment,” rather, it is “beautifying and protecting your fence.” The question is, are the aesthetics worth the extra expense to you? Before we leave the topic of fences, lets run the numbers on your typical fence with wooden posts, because most wooden fences are not installed with metal posts. We’ll take your regular fence installed by your typical fence installer, ie. the concrete is below grade which means stain will not increase the lifespan of your fence. $12,000 initial build, and $3,000 initial stain and every three years to re-stain, and the cycle restarts every twelve years. The cost of owning this fence into perpetuity is $2,000 per year. The cost of owning the same fence but never staining it, is about $1,200 per year. In this scenario, the cost of a pretty fence is $800 more per year, which is 67% more. So now we have our low and high examples. The cost of a pretty fence will typically run you anywhere from 29% to 67% more. The choice is yours. To beautify or to not? You decide. For me personally, I’ll always choose to stain over not, because unstained wood fences look ugly to me. But a pretty stained fence makes me feel good, and how I feel is important to me. An ugly fence brings out the pessimist in me. A pretty fence brings out the optimism and gratitude.

What about decks? A 16×32 deck attached to your house might run you $18,000 to build. To stain that deck might run you $4,000. If you never stain the deck, all of the decking and railing will need to be replaced within 12 years, and the entire deck will need replacing within 24 years. The cost of this deck into perpetuity with no maintenance is $1,140 per year. That’s the cost per year to replace half of it every 12 years and the entirety of it every 25 years. If you instead stain the floor every 18 months and the entire deck every 3 years, then it’ll last you maybe 40+ years. The cost of maintaining the deck regularly and replacing every 40 years is $2,400 per year. That’s 110% more expensive to keep it stained on a regular basis than to do nothing and repair and rebuild every 12 and 24 years. Let’s suppose that regular staining were to extend the lifespan indefinitely, an inter-generational deck that transcended the lifespan of long-lived empires. Let’s say this deck is was $18,000 to build, lasted a whopping 1,000 years. Well, given that the cost of regular maintenance is $2,000, no matter how long it lasts, the cost of maintaining it will never be cheaper than the cost of continuously re-building it. The cost per year of this 1,000 year-old deck would be $2,018 per year. That’s 77% more expensive than not staining it.

Just for fun, let’s do a quick run-through on the numbers for a log cabin. Let’s suppose cost of construction on a log cabin is $440,000. Cost of moving, storage, and housing a family for half a year to allow time for re-construction, and cost of demolishing and removing the old structure is $80,000. And cost of staining this cabin is $25,000 every 5 years. Lastly, let’s suppose that the cabin will last 40 years before it needs to be rebuilt if it is never stained, and lets suppose that it will last indefinitely if it is stained on a regular basis. The cost per year of owning this cabin and never staining it but simply rebuilding it every 40 years is $12,000 per year. The cost of this cabin and maintaining it with coats of stain every 5 years is $10,500 per year. And there we have it. Finally! Something which is actually cheaper to own if maintained than if not.

6) What Is The Process To Staining A Fence?

The process of staining a fence is very simple. You will need a moisture meter, a good stain brush, a paint sprayer, a degreaser and/or mineral spirits, some masking, and some rags. You could brush the entire fence, but it will take way longer and you won’t be able to cover every square inch of it as thoroughly as you can with a sprayer because a brush won’t get the cracks between pickets like a sprayer can. A brand new fence can be stained as soon as the moisture content is below 16%. The lower the moisture content, the better. The higher the moisture content, the less stain the wood will be able to absorb. In our climate, about 10% moisture is the lowest you’ll ever see. I’ve seen as low as 6% to 8% in the summer on wood that is in direct sun all day, but if you poke around, you’ll find that the north facing shady areas will be coming in at 10% and above. 16% is the max that you want to see. 12% and below is the ideal though. But if you see readings between 12% and 15%, don’t fret, that’ll work just fine too. Now all you do is apply stain and continue applying stain until you see that the stain is no longer absorbing in. One good saturation coat is all it takes. If you’re a perfectionist, then back brush it as you go down the line. Oftentimes I’ll do a saturation coat, and then a quick and light second coat followed by a back brushing. If the fence is not new, or if it is but you want the absolute best outcome possible, then you’ll need to wash it before staining it. You’ll need a way to apply chemicals, and you’ll need a pressure washer, ideally one that is at least 3.5gpm and 3,500psi. Wet the wood, apply sodium metasilicate (not bleach), wash with high pressure (but don’t fuzz up the wood), then apply Oxalic Acid, then rinse really well with low or high pressure. Let dry, and you’re good to stain.

7) What Is The Process To Staining A Deck

The process of staining a deck is the same as a fence, except for there’s one more step. After washing, sand the deck floor and handrails with a 60 or 80 (I prefer 60) grit sand paper, or use an Osborn Brush on a large grinder or polisher (Osborn brush is my preference). The purpose of this is to smooth out the finish so that the stain will come out with a smooth, clean and even look. If you skip this step, the finished product will look more rough, splotchy, and the grain will be less noticeable because the rougher wood soaks up more wood on the surface. After sanding then it’s time to stain away. Decks that have already been stained before may not need sanding if they were sanded the first time they were stained and if it has aged well since the last sanding. Here are a couple tips on staining: 1) Start from the bottom and work your way up. That way if you drip whilst you’re working, when the drips hit an already stained surface, it’s less likely to leave a noticeable drip mark compared to if it drips on an unstained surface. 2) Use plastic to mask porous surfaces such as old plastic, fabric, etc. Concrete and other hard surfaces can be liquid masked with a solution of Dawn dish soap and water, keep surface wet for entire time that you are staining, sometimes this means running a water hose on low underneath the deck whilst you’re working. Mineral spirits and any good degreaser can be use to dilute and wash away stain that gets on a surface you don’t want it on. The key is to make sure that the surface is wet before stain gets on it, otherwise it’ll be a lot harder to get the stain to wash out of it. And make sure you get to it quick, the longer it sits the harder it’ll be to remove. Lastly, smooth surfaces such as metal and glass are less worrisome as they can usually simply be wiped down after everything is stained and you are cleaning up. Since metal surfaces, and glass etc. are not porous, the stain just wipes right off.

8) What Is A Maintenance Coat?

A maintenance coat and the process of applying it is the same thing and process as the first time an initial coat of stain is applied to a deck or fence. The only difference is, the cleaning might be a little quicker and easier, and it might not require any significant amount of sanding since it was already sanded the first time around. It might absorb slightly less stain as well since it likely still has some stain in it already from the time before.

9) Can Outdoor Furniture And Other Exterior Structures Be Stained?

Yes. Any exterior wood surface can be stained and is best preserved by being stained. This includes, wood furniture, sheds, log cabins, pergolas, gazebos, docks, etc, etc.

10) Why Is WGL&C A Good Company To Hire For Your Staining Project?

Staining is not difficult. But not many people get it right either. More people do it wrong than right. The most common mistake people make is they choose the wrong product. Whether you use us or not, do not make this mistake. It is a very costly mistake, and sometimes is not even worth spending the money to correct due to the cost of stripping off a film-forming product. My recommendations are to use SSE or TWP 200 series stains. There are some other good ones as well though. Here are a few more good ones: Timber Pro, Wood Defender, Boodge, Armstrong Clark, and Cutek. Ready Seal is alright but would be my last choice from the ones previously mentioned. If you are going to hire a company, first and foremost, make sure they’re using a good product. If they’re not, that’s your indicator that they don’t know what they’re doing, and you’ll be better served finding someone who at least knows enough to know what’s a good product and what isn’t. Another question is to ask them what their cleaning process is. If they say bleach, then find another company. If they say just water at a high pressure, but your fence or deck has significant amount of mold or other stains, then find a different company. With that being said, if you’d rather avoid the potential mess of a lesser knowledgeable company, than choose us. We know what we are doing. We’ve run through the gamut of mistakes via experience and research and are not using your project as an experiment. Our results are predictable and professional. Choose the best. We look forward to restoring the natural beauty wood to that deck, fence or log cabin of yours.