Hardwood Floor Refinishing - What to Expect
There are several methods of improving the appearance of older hardwood floors with complete refinishing being the number one choice. Done properly, this procedure removes all older finishes making it compatible for any new finishes being applied. Failure to do so often results in failure. Other forms of improving your floor appearance can be found at the page links near the bottom of this article.
When Should I Have My Floor Refinished?
Complete refinishing may be needed when excessive wear becomes apparent or when raw wood becomes visible. Scratching may also be driving you bananas, or maybe you’re just tired of that natural look when many are now (2017) are seeking darker stained floors. Perhaps the gloss level isn’t to your desires either. Or maybe you’re trapped in a time warp with your grandmother finding yourself waxing floors the old fashion way.
When to have the work done depends on your expectations. While most people can live with the everyday abuse wood floors get as scratches, dings, and dents lead to adding character, others prefer that sleek contemporary look. In that case, resurfacing every five years may suit your needs.
Will My House Be A Dust Bowl During the Work?
This depends largely on who is doing the work. Some of the better professionals that care more about your indoor air quality have invested in dust extraction systems. Others may just have a bag attached to their sanding equipment which is not considered a good way to keep airborne dust out of your house.
Dust extraction systems can remove a large amount of dust, but it is not 100% effective. The better finishers are likely to leave your home without you doing much cleanup as some take it to another level in cleaning all of the work environment prior to any finish application.
For those that may not like the higher cost, chances are great you'll be living in a dust storm until the finishers leave. Dust can find its way anywhere; into kitchen cabinets, heating and cooling system vents...everywhere unless you protect everything during the work. If costs are an issue, insist to the refinisher that he tape off rooms, cover drapes, and call in that cleaning crew once the work is done. Poor dust control may also have an effect on the final appearance, not to mention everyday health.
Maybe the finisher did a great job of insuring the final coat was free of dust particles, but floor finishes need time to cure. He may leave a flawless job, but let's say the kids come home from school and other fine dust particles are stirred up. You now have a not so perfect finish job.
Recognizing What Your Floor May Need
The short video below deals with what to expect with a floor cared for over the years, but has lost it’s sparkle. Installed in the 1970’s, you’ll see what the common procedures are in regards to sanding sequences and grits used. Older heavily waxed and varnished floors are briefly discussed.
Related video - removing heavy dog stains
Visitors Are Coming. When To Move The Furniture Back?
Some finishes will take longer to cure, but friendlier water based finishes will take the least amount of time. Conditions can vary and depends on relative humidity within the home or conditions outside if you want to speed up the odor removal with an open house. Any experienced floor finisher can better evaluate when it is safe to do so. You may also want to ask them about area rugs and when it is safe to use them.
How Long Does It Take? ¹
I've based the following on how long the work should take. Included is one 400 square foot square room with furniture moved and ready to go for the finisher. Water based finishes should take two days, while oil based finished three.
How Many Times Can My Floor Be Sanded? Can I Check?
How many times a wood floor can be refinished or sanded will depend on a number of factors. A summary is included below with page links for more information on each type.
Pre 1900 Hardwood
This period pre-dates the wider spread use of regular tongue and groove flooring. Thicknesses vary but a common lies near the one inch range, which later became 7/8 inch when tongue and groove came into being in the 1880's. Considering most of these floors have no tongue and groove the floor can be sanded more times than others providing nails are set along the way and continue to hold the floor intact.
The only potential drawback with some older floors may be in the structural support of the thinner flooring without a subfloor. Thinner flooring would tend to be less structurally sound. Excessive squeaking and creaking would be a symptom of this kind of thickness. These older types are much easier to asses in how much wood is left to sand off. Simply find an area that shows the original floor joists below, insert a business card or similar until it rests on the floor joist. Make a mark, remove and measure.
Older Tongue And Groove
As times moved forward, older tongue and groove products were manufactured with a thickness of 3/4 of one inch. However, the floor cannot be sanded successfully with good results below the tongue and groove area without exposing nails used to install the floor.
Methods use to determine the amount of hardwood above the tongue and groove are similar to pre 1900 types. If there is any gapping present between boards, insert the business card remove and measure. The business card will rest on the tongue portion of the board. Prior to any measuring, vacuum any dirt that may be trapped in the area.
Another measuring option includes checking the perimeter of in floor heating vent openings. Remove the vent cover and check the condition by eyesight looking at the tongue and groove (image below) profile.
Exception: Post World War II floors milled in the USA would sometimes be 5/16" thickness without being tongue and groove. This time period ranges from the mid to late 40's due to the lack of available supply. Some of these products are also still being used in new installation within some geographical regions of the USA, particularly the bay area of San Francisco.
Newer Tongue And Groove
For all common tongue and groove, the frequency in when they can be refinished or sanded depends on how much hardwood is left above the tongue and groove. The first illustration shown above indicates a new solid pine floorboard. Thickness from top to bottom is 3/4 of one inch. The arrow indicates the amount of above the groove area. For brand new products the measurement runs in the 1/4 inch range.
Micro Beveled Prefinished
Throw in the wild card on this one. How many times they can be sanded will depend on what appearance you want to achieve. Most times the bevel will have to be sanded completely out to achieve a desirable look. Otherwise chances are good you will be left with a non uniform bevel depth appearance.
Here's where things get a little different. How many times will depend on the wear or veneer layer of the product. Let's say for instance you just purchased a Bruce Lock and Fold floor from Lowes. The amount that can be sanded or refinished off the top is minimal. The photo on the right best illustrates the situation.
Considering the overall thickness is only 3/8" (top to bottom) one can get a good idea how thick the top layer is. It's located at the point of the arrow in a darker shade. Simple math makes it look like the surface layer is 1/8" the thickness of the board; making the top layer about 1/16 of an inch thick--- if that! In a perfect world a very good professional could sand this floor once but I would not have any money on the bet.
Other improved engineered products in the 3mm range could possibly be sanded twice and not the three times many manufacturers lead you to believe.
Refinishing Hand Scraped Products
Time will tell whether or not the rage for distressed, hand scraped, or sculpted flooring will remain stylish. As of this update July 2019, sales remain strong but the trend is more towards mild character floors or smooth brushed textured floors. The latter will require the least amount of work should anyone want to sand any of these floors back to a more traditional smooth appearance. My thought going forward. What’s it going to be like in 2030, for example. Will these floors make for a tough real estate sell? Only time will tell.
Several Options. But Do You Still Want The Hardwood?
I feel hardwood will still make up a good portion of the hard surface flooring market (includes tile and stone variations) extending out a few decades, but the rage for distressed will probably fade. A large demand will exist for experienced professionals that can finish distressed floors to improve, keep or create a smooth appearance.
Improving The Appearance
By improving the appearance I am specifically looking at methods to keep the original look. Major machine manufacturers are already marketing tools to do such. One is called the Floor Abrader made by Clarke Equipment. The benefit here lies in the use. Specifications state the Abrader can remove existing finishes on distressed flooring without altering the appearance. Once the process is complete, newer finishes can be applied.
I Hate The Look. Let's Sand It Flat!
Considering how these floors were constructed some can be successfully sanded to a smooth and flat appearance, but the vast majority cannot. Engineered hand scraped, depending on the bevel and depth of distressing will probably have to be replaced, or new flooring installed over.
When analyzing how these types were made I'll provide a better understanding why they’ll need replacing. Lets take an example of the Anderson Virginia Vintage line; a large seller since they became fashionable. Much of their product is contoured severely on the side and end joints. Considering the overall thickness of the veneer (3/32”) attempts to sand flat the floor will be marginal at best.
Another key in determining the potential to smooth sand the floor is the condition of the original sub floor. With all the floors installed I would venture a guess that two thirds paid no attention to the flatness. Flatness is critical when it comes to sanding minimal material. Any irregularities will cause sanding equipment to sled the rises and falls in the hardwood. In other words, floor sanding machines run on a parallel plane. Climbing minor hills (rises) will cause the equipment to dig deeper in some parts of the floor than others.
So It Looks Ugly. Other Options?
The resulting appearance will become areas where the veneer layer has broken through. Layers under the veneer run in opposite directions; the same as plywood. The final result will be a floor showing random areas of disparity. Options to save could include very dark stains, or painting with solid colors. Considering this is an area not touched at the moment we’ll have to see what develops. Trends and styles can be strange.
Remove, Replace Or Install Over?
For floors glued to the sub floor, removal will be intense and time consuming not to mention extremely messy. Floating systems will be a breeze to replace with nailed types falling in behind. Nailed floors, specifically for ¾ inch solid hardwoods will become very trying, while most thinner engineered hardwoods are somewhat simpler depending on how many nails were used.
For those less inclined to take the removal route, newer floors can be installed over the old with the exception of floating. However, careful attention to the soundness of the existing floor is important for the new to perform just as well. Newer types may require an additional sub floor, or should be installed in opposite direction to provide more stability.
¹ Developments with onsite UV curing machines can speed up finishing times substantially. Few professionals (2017) at this time offer the service.
From Our Readers:
Subject: Dishout & Hard Plating
Question: We are in the twin cities area and had a new site finished floor installed. It looks great but there are some areas where the floor looks more grainy than other areas. The finisher calls it dishout and wants to hardplate the floor. Can you explain what these terms mean?
Reply: Dish out occurs when more of the soft grain of the wood has been removed. Hardplating is a method used to smooth the area free of irregularities. A hard plate is attached to the bottom of a floor buffer. The name is derived from the condition of the plate which is very rigid and has no padding. This procedure also helps remove chatter marks that almost looks like a wave or rippling effect the drum sander has caused on the floor. Other uses can be edger marks that may be visible.
Subject: Chatter Marks
Question: What causes chatter marks when using a drum sander?
Reply: A number of factors can cause this condition. A few leading causes are basic maintenance that has been overlooked, drum paper is not on the machine properly, drum sander is out of balance, bad drum, wheels are worn out, and or bad or cheap machine belts. Condition of the floor itself can have a effect as well with high or low floor joists and loose boards. Once the machine hits these areas while vibrating at the same time, the effect can continue even if you're on a flatter surface.
Subject: Brazilian Cherry Filler
Question: I'm looking for a perfect match to fill cracks in my new brazilian cherry floor. I've heard this stuff changes color radically, but is there a filler that changes color too?
Reply: Some professionals simply use the fine sanding dust from the edger machine and mix with a resin or lacquer. Often the disadvantage here is the mixing materials don't allow the filler to change color like the actual floor. Other ideas include sourcing a color putty that matches the color of the floor once aged.
Subject: Types Of Sand Grit Paper
Question: We have a finisher here in Denver that insists he start sanding our floor with 36 grit sand paper. I do wood working as a hobby and I just can't get over the fact he would start with such a course grit and the floor is fairly smooth. What gives?
Reply: I have some experience finishing furniture and understand where you're coming from. Chances are he may feel more comfortable using a courser grit to start and properly flatten the floor. You may not see what he sees. Providing the proper intermediate grits are used up until the final sanding passes his method may be what works best for him. Some finishers are very proud of their techniques. What works for one may sound strange to another, but the final result is what is important.
Subject: Trio Sanding Machine
Question: i'm a flooring contractor is the Seattle area and looking for information about the Lagler Trio sanding machine. A few guys tell me it's worth the investment but at close to $ 6,000 I'm gunshy.
Reply: Some benefits of the Trio include a reduction in the use of the flooring edger, considering how close the machine can get to walls or baseboard. Other benefits include the ease of use for inexperienced users. You will not get the drastic effects a drum sander can cause, but it's not open to skipping instructions for proper use. They are especially useful with multi directional floors as well. A consensus indicates dust control as another plus.