Plank Flooring and Wood Floor Finishes

Don:

We are looking into putting red oak floors throughout our home. We have pretty much narrowed down all of the details except for the size of planks we should use. Will there be any difference in the structural stability of a 4" plank vs. a 3 1/4" plank? We have heard that the wider the board, the more chance there is of some movement down the road. So, what size is your personal preference? Is there an industry standard?

One other question I have is regarding the natural ambering that occurs with red oak. Does using a Glitsa finish help reduce the amount of ambering that occurs?

Thank you so much for your time.

Plank Types, Sizes and Application

Unless your home is situated near a body of water, deep in the woods or somewhere else where significant shifts in internal moisture can be anticipated, the difference between 3- 1/4 and 4 inch plank will probably be negligible. Where issues or concerns exist regarding plank width or moisture migration, I generally recommend the use of a rift and/or quarter sawn cut. With the advent of high quality elastomeric mastics especially formulated for wood flooring, I often recommend the use of a full spread solid wood flooring mastic as well as nailing.

Four inch plank is probably still more standard than 3-1/4 inch plank but there are lots of new products being introduced these days (especially from other countries) utilizing the 3-1/4 inch profile.

Technically, wood flooring boards 3 inches or wider are considered plank flooring. In the past, domestic manufacturing of most plank wood flooring was fairly standardized with plank sizes graduated precisely at one inch increments from 3 to 12 or more but more commonly 3 to 8. Conifers and reclaimed materials varied from this somewhat informal flooring standard due, I believe, primarily to price and value. Half or quarter inch intervals were common, if not even more standard for these products.

Wood Flooring the Environmental Choice

While soft wood lumber intended for flooring competed head-to-head with that intended for the general building supply industry, hardwood lumber sold to the flooring industry was (and still is) a by product or “fall down” from the dimensional hardwood industry. Hardwood lumber graded as ‘gifted in character’ (that is abundant in knots, holes, wane, burls or other qualities generally perceived as “defects”) was sold to “fall down” manufacturers as a by product of the dimensional hardwood lumber manufacturing process.

Wood flooring manufactures are (for the most part) at the bottom of this list. Even pallet manufacturers need boards 4 inches or wider. Not wood flooring manufacturers. A pallet manufacturer also needs boards 3 to 3-1/2 feet or longer; but not a wood flooring manufacturer. So the hardwood lumber sold to most flooring mills is heavily picked over, and generally not as appealing to other manufacturers. That lumber, typically graded 2 Common, won’t sell at premium prices. That’s what’s sold to the wood flooring mills.

The flooring mills used to turn their “fall down” into firewood for their kiln furnaces or given to anyone willing to remove it from the premises at no charge. These days, firewood and sawdust are made into panels, wood pellets or sold as smoker fodder.

An Important Note: As of this writing, supplies of hardwood lumber have dwindled to their lowest level in many years due to the permanent closure of many hardwood lumber plants. All domestic species are in short supply, but White oak in particular. This does not mean there is a shortage in our hardwood tree population or that there has been an over demand for the product. Far to the contrary, our country’s hardwood tree population is at the highest level it has been in over 200 years. Since hardwood flooring is developed primarily as a by product from associated hardwood industries, the severely limited number of hardwood lumber companies currently has caused a temporary overtaxing of the entire supply system. Although the demand for hardwood flooring has dropped along with that for other hardwood products, it has not experienced the same level of diminished demand as have other hardwood industries. We have been told to expect hardwood flooring prices to continue to grow at unprecedented rates and to anticipate shortages for various hardwood flooring products for some time to come.



Antique and Reclaimed Flooring

Antique or reclaimed lumber normally requires re-sawing to make it more useable. Historically, its been marketed to by-product manufacturers, like the wood flooring industry, that could make better use of boards that were shorter and more narrow than that required by other hardwood or softwood manufacturers. Standard ‘commodity’ flooring mills never seriously attempted re-milling and selling antique or reclaimed lumber as flooring. That required far too much handling and care than they were willing or able to put forth. So, small “boutique” flooring mills began popping up in the late 70s and 80s as a “green” source for old growth lumber products. Initially, this was due to the limited price point that “old” lumber drew on the open market. These days the costs for old lumber have grown and its availability dwindled to the point that “antique” and “reclaimed” lumber now sells at premium prices.

Pretty much from day one, plank wood flooring milled from old beams, boards or reclaimed logs was milled utilizing the “live sawing” method. This is normally considered to be the most “green” milling process where the maximum possible yield from every piece of raw material is forthcoming. Then, a “mill run” or “wholesale” grading process is often implemented. This means basically that every single piece of material sawn from the log, board or beam is included in the flooring lot. So ¼, ½, and ¾ even 3/8, 5/8, and 7/8 intervals were often added to the normally even numbered plank widths with antique reclaimed flooring boards.


Variable vs. Random Width Plank

All those different widths with uneven intervals created math havoc with the resellers of antique reclaimed planking who wanted to sell the installers plank flooring in equal lineal feet. Their standardized tables that spelled out the precise square footage requirements of each width for a “variable” width plank floor didn’t allow for so many different and uneven combinations of widths. So they attempted to sell the plank flooring by the “random” width rather than the more classic “variable” width.

A “variable” width plank floor creates more of a standardized pattern to the floor installation’s appearance since it contains the same number of rows of each width. A “random” width plank floor’s installation must be completely arbitrary since the square footage and therefore lineal footage of each available width will vary. The appearance of a “random” width floor installation can be somewhat disordered to some people. It’s interesting to note that many plank installations dating back centuries contained “random” width planks. Since they utilized whatever was available to them at the time, their flooring rows represented such. On occasion, some rows were even begun with one width, then divided mid row into two planks of exactly ½ that width to finish the row.

To help mills and resellers sell their increasing cumbersome variable plank widths in the classic “variable” width format, I created a computer program called WIDTH to take care of all the math for them regardless of the number or sizes of widths. I have to confess that program is in dire need of a facelift. I wrote it in C and Assembler languages and it needs updating to run with all the bells and whistles on today’s super fast processors and GUI platforms. But for the guys willing to run it on a DOS platform, it still does a great job.

Some History of Floor Finishes

When Glitsa and Synteko (the two most domestically popular acid-curing floor finishes) were first introduced into this country, 40 years ago or more, they were highly touted as non-yellowing floor finishes. But that was in comparison to the major floor finishes on the market at the time...primarily oil-modified urethanes. When it was first introduced, oil-modified urethane was seen as a great advancement over the more commonly used floor finishing products at that time, varnishes, penetrating oils and waxes.

The oil-modified urethanes, of those days, yellowed considerably with age and sunlight as did virtually all the other oils, sealers, varnishes and waxes in use, but they could be counted upon to cure faster and provide a more durable surface film than their predecessors. Essentially, what an oil-modified urethane (or polyurethane as they were called in our industry) did for floor finish films was to provide polymers that would help the oils they were combined with cross link better for tougher finish films and do it much faster than the oils could alone.


State-of-the-Art Floor Finishes

Today’s state-of-the-art floor finishes are by and large waterborne products. The acid curing and moisture curing urethanes so popular for the past 25 or 30 years are being rapidly replaced by harder wearing, less toxic, waterborne coatings. Interestingly enough, many of the old style oils and waxes are enjoying renewed popularity. They offer a depth of color and ease of repair that none of the newer urethane products can boast. The hard wax oils, highly touted as more “green”, predominately from Europe, are variations of these penetrating oils with (in some cases) less toxic solvents. Keep in mind, just because it’s better for “the environment” doesn’t mean it is cleaner or less toxic for the user. A great example of this is Tung Oil. Tung Oil is considered food grade once it has dried, but it’s an accumulative toxin to the humans applying it in liquid form. I’ve had several good woodworking friends, bowl makers, turners, carvers and fine woodworking artists who’ve had to seek alternate trades after reaching toxic shock levels working with Tung Oil.

Most single component waterborne floor finishes are acrylics, urethanes or a combination of the two. Which is best depends on which manufacturer’s rep you happen to be speaking with at the time. The resins or binders utilized in all the various products are made by only a few different companies throughout the world. So except for the amount and type of resin, the end products don’t vary a great deal. Resins are almost always the most expensive part of a floor finish’s formula. So, the tougher, better resins and the percentage of same will cause the coating to cost more. Therefore, a good rule of thumb, is all things being equal, the more expensive the finish the better its quality.

Durability Rumors

You may have heard from some of the “Old Timers” that waterborne floor finishes are no good. Well, I’m an “Old Timer” and let me say this, the top-of-the-line coatings like Danish Finish and Danish ProSport have very little in common with the water-soluble coatings that came out 30 years or so ago. Those finishes were relatively expensive and difficult to use. Today’s water borne finishes are much easier to use and can be made relatively inexpensively. That makes them prime candidates for the DIY market. Go into virtually any hardware store, DIY center or box store and you’ll find a wide variety of inexpensive waterborne finishes lining the store shelves in the flooring department. Beware of the claims these products make. They have little in common with the top quality water borne floor finishes available to the professional, except that they are water soluble.

The really top-of-the-line wood floor finishes (the professional grade types of products) are NOT cheap...whether they’re waterborne or oil based. A good rule of thumb is, the cheaper the ingredients the cheaper the product. Professional grade, single component, Danish Finish and its two component industrial strength big brother, Danish ProSport, are significantly more expensive than their box store cousins. They are marketed to professional floor finishers and discerning do-it-yourselfers. These extremely high quality products have virtually no yellowing characteristics and contain exceptionally strong UV inhibitors to boot.

Where to Buy Top Quality Floor Finishes

It’s like what I told my son recently when he was in the market for a drill. He knew that I liked my Milwaukee drill, the one I’d owned for over 30 years. He said he could get a Milwaukee drill at his local box store for $20 to $30 but definitely for under $50. Why should he pay the $150 to $200 he was quoted for a Milwaukee drill at a construction supply house? My response to him was this. If you’re going to use the drill just once or twice a year and for short periods of time, buy a cheap one. You’ll go through a number of cheap drills over the years but you’ll probably come out even in the end. But, if you intend to use it regularly, want to keep it your whole life, or if you’ve got some serious work in mind for it, you’ll want to buy a professional grade drill motor and they don’t come on $20 or $30 drills.

It’s the same with most construction supplies or products. Professional grade items just don’t sell well in box stores. So if you want a good professional grade floor finish…one that will stand up to everyday wear and tear…you’ll need a top quality product. Whether you’re in the market for a good polyurethane, penetrating oil or water borne floor finish…expect to pay for quality. Professionals know that. Their reputations are on the line every time they put a product down on a client’s hardwood floor. Serious professional wood floor finishers insist on top-of-the line floor finishes…like the Danish Finish and Danish ProSport.

For professional grade polyurethanes and similar products we recommend and sell Lenmar Products. I have found them to be made of the finest quality ingredients and meet the exacting requirements of our demanding hardwood floor finishing clientele.



All acid-curing finishes (like Glitsa and Synteko) are considered professional grade. They contain so many toxic compounds and flammable solvents that the manufacturers generally restrict their sale to professionals only. That is how we enforce their sale in our wholesale supply division as well.


Comparisons of “Swedish” to Waterborne “Danish” Finishes

A one-on-one comparison of Glitsa or any other acid curing finish to a top-of-the-line waterborne product is not entirely feasible. There are a great many differences in addition to the obvious toxicity issue. Originally, acid curing products became popular not just because they didn’t yellow as much as their predecessors but also because they could be utilized as both sealer and finish. Many of the older floor and wood finishes needed a pore or grain filler along with a separate sealer in order to leave a consistent film face on the wood. Without this smooth film face, the surface would not look as beautiful and would wear prematurely.

Ironically, part of the acid curing floor finishes popularity came about because they left the floor’s surface less smooth. There were some who liked their hardwood floor’s surface finished without grain or pore filling and without staining. It was called a “Natural” finish. It required an extra coating (for a minimum of 3 total coats) of Swedish (acid curing) Finish to protect properly but was a look that could not be achieved in any other way.

To this day, that “Natural” look is still unique with hardwood flooring…particularly with red oak. The acid in the acid-curing finish reacts with the tannins in the oak (particularly “red oak”) causing it to turn a rather bold reddish brown when coated. Other solvent-based coatings will usually have a similar but somewhat more subdued effect on that wood. The same is true of American and Brazilian Cherries. These cherries will darken, intensifying their reddish hue over time, usually progressing to a brownish hue depending on the strength of sunlight striking them.

Appearance remains one of the single biggest differentiating factors between the “Natural” (no stain) finish application of a top quality product like Danish Finish or Danish ProSport water based finish and a Glitsa, Synteko or other acid-curing finish.

Still, in the final tally, waterborne coatings are gradually overcoming this last big hurdle. In high rise, multifamily homes or commercial venues with other tenants in place, a waterborne coating must usually be used due to toxins, odors, and flammability. Where durability is paramount, the Danish Finish or Danish ProSport can’t be bested. The difference between a top quality waterborne coating (particularly one like the Danish ProSport) and an acid curing finish like Glitsa or Synteko is like comparing apples to oranges. The waterbornes cure faster and will take so much abuse and still look beautiful, that there is really no comparison. The top-of-the-line waterbornes are more clear, have minimal if any yellowing and contain extremely strong UV inhibitors.

For a do-it-yourselfer, there is just no reason to settle for anything less than quality top-of-the-line waterbornes like the Danish Finish and Danish Prosport. The Danish Finishes, unlike most professional grade products, are extremely easy to apply. Getting a professional grade coating with either product has never been easier with any product, much less a professional one.

Stain Applications

If you plan to stain your floor, you'll probably end up utilizing a solvent-based product. In my opinion, there still is no substitute for solvent-based stains when doing wood floor finishing. This could change soon as many manufacturers are working hard to solve this problem.

In the mean time, if you planning to use an acid curing finish like Glitsa, Synteko or one of the other lesser known brands available, expect to see some slight yellowing of the stain color initially (particularly pastels) and even more over time. Part of this is due to the finish, part to the stain and part is due to the tannins, oils and resins in the wood.

In you plan to use an oil modified (polyurethane) finish, you should expect even more yellowing both initially and over time. One extra point regarding the use of polyurethanes. As a general rule, it will take 3 coats of acid cure or waterborne urethane to get the same film thickness build as two coats of polyurethane floor finish.

If you plan to use a waterborne urethane over a solvent-based stain, you’ll need to allow a little more dry time for your stain. This is especially true for highly pigmented stain colors, especially pastels or whites. But, expect to reap big dividends from the clarity of the finish film, its resistance to fading and color changes over time or with sunlight and loads of extra durability from foot traffic.

If you plan to use a penetrating oil (tinted or not) or one of the hard wax oils, espect considerably more dry time and curing time. I find lots of folks presold on these products from a environmental standpoint without realizing the whole story. When they find out that not only are these products not as “green” as the waterborne urethanes but also require substantially more TLC and maintenance, they hastily move away from them in favor of a more user friendly, environmentally friendly and user friendly choice.

Strictly speaking, the truest...clearest coating that you can apply to a floor is a top-of-the-line waterborne urethane...and...it is the toughest of the site-applied floor coatings available today.

In the end, there really is no WRONG choice…only one that is better for you and your application.

Hopefully this helps you. Please feel free to ask other questions.

Thanks,

Don

Don Bollinger don@woodfloorco.com Wood Floor Products, Inc. (206) 622-6996