‘Did You Know’ Episode 7 – Dog Nails and Their Ability to Damage a Wood Floor

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Episode 7 – Dog Nails and Their Ability to Damage a Wood Floor

Just as a woman’s high heels can dent and crush the fibers of a wood floor, a dog’s untrimmed nails can produce the same crushing action on the cells of a wood floor. As mentioned in the diagram below regarding high heels, your dog’s nail can exert the same psi.

As a dog slips on a finished surface, they will try to grip the surface with their nails. When doing so, the pressure applied to the wood will cause the wood fibers to dent. This may be viewed as a scratch in the finish but it is actually denting the wood. Unfortunately, even the most durable finish systems cannot make the wood harder.

Truthfully, any dog, of any size and of any age can potentially do this to a hardwood floor. A more rambunctious puppy that likes to run and play or even an older dog that likes to run to the door at the sound of a ringing doorbell would have a greater potential for this damage.

While most pet owners are unwilling to quarantine their dogs out of the living space of the home, here a few tips to minimize this damage on your hardwood floor:

  • First and foremost, keep their nails trimmed and rounded off (avoiding sharp points during trimming).
  • When choosing wood flooring for your home, choosing a denser wood specie can minimize the possibility of this type of damage. Maple, Hickory or Brazilian Cherry are great examples.
  • Higher sheen levels and darker stain colors will potentially show this damage more. Utilizing a Satin or Matte sheen level will minimize the reflection of light, thus masking the dents potentially being put into the wood.

If you are looking to repair this damage that has already happened to your floor, recoating it with Matte sheen may mask the damage. In worst case scenarios, the floor may need to be resanded to completely remove these dents.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.


Along with the Floor Care Products available through Gehl Flooring, check out these additional Floor Protection products.

‘Did You Know’ Episode 6 – Long Term Hardwood Floor Care

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Episode 6 – Long Term Hardwood Floor Care

Today you can find many suggestions on how to maintain hardwood floors. While some old time remedies may still be relevant, it is best to follow these suggestions for the best performance of the investment. Understanding realistic expectations of wood floor maintenance up front is important. Hardwood floor owners who realize that their floors aren’t impervious to an onslaught of spills, grit and water will be happier with their floors. You can prevent most problems before they occur by following the below care and maintenance, keeping a hardwood floor looking its best and lasting longer.

Added Protection

Nothing is more discouraging than discovering scuffs or scratches on your newly finished hardwood floor. Wood is a product of nature; therefore, it can be dented or scratched by dog nails, high heels, heavy appliances and sharp objects. Most of these scratches could be easily prevented by the following these Do’s and Don’ts…

DO

  • Support furniture and heavy appliances with wide-bearing, non-staining gliders or casters.
  • Move appliances and furniture by lifting and placing in place. Try not to slide or roll them on a hardwood floor.
  • Place a quality door mat at the entrance of your home to help protect the floor from abrasive dust, dirt and grit, thus save time on unnecessary clean-up.
  • Place area rugs in high traffic areas to make long-term maintenance easier and less expensive.
  • Keep the indoor relative humidity between 30% and 50%.

Don’t

  • Don’t use wax, or other wax-based maintenance products on your wood floor.
  • Don’t use soap or other household detergents.
  • Never use a wet mop or pour water directly on the floor surface.
  • Don’t use any alcohol, or ammonia based cleaners.
  • Don’t clean newly finished floor with Wood Floor Cleaner, or any other cleaner, until the floor is fully cured. Check with your contractor or the manufacturer of the finish for cure times.

Deep Cleaning/Re-Oiling

Just like other floor coverings, your hardwood floors may become too dirty to clean with a simple cleaning. At this time, many floor covering companies offer deep cleaning options that will utilize specifically designed equipment to deep clean and scrub your floors, removing any build up left behind by the weekly cleaning. If you have an oiled floor, many manufacturers sell an oil/cleaner that should be periodically applied to your floor to maintain its appearance.

Recoating/Restoring Your Floor

With time, signs of normal wear and tear should be expected. It is natural and happens to all wood floors. To restore the luster of your floor and extend the wear layer of finish, recoat your floor with additional coats of finish (if a traditional urethane coating has been used) or the correct restoration products if your floor has been coated with a hard wax oil or penetrating oil. Make sure your contractor is using the recommended recoat system that is compatible with the finish to give the existing floor a proper deep clean and prepare it for recoating/restoration.
Recoating should be done when necessary. Don’t wait until the finish has worn through to raw wood. Call your professional flooring contractor for advice as soon as you see a wear pattern developing on your floor surface.

Accidents Happen

No matter how carefully you take care of your floor, sometimes accidents just happen. Dropped packages, sliding furniture and other things can dent or scratch any wood floor finish, regardless how tough it is. Some of these problems can be solved easily with a simple solution, while others might damage your floor too much to repair by yourself. Don’t worry; there are many talented floor contractors who will be more than happy to help repair your floor. For simple repairs, some manufacturers have repair kits available to help mask slight damage to your floor.

Throughout the Life of Your Floor

The environment of the home should be stable and maintained throughout the life of the floor. Even with correct conditions, floors will shrink and expand as seasonal changes occur. To minimize these changes, maintain a consistent temperature and humidity for your floor to perform as designed. The manufacturers of your flooring may have their own suggested perimeters but the National Wood Flooring Association (NWFA) states these conditions should be between 60° and 80° and 30% to 50% relative humidity. Installers take many steps to make sure the flooring is installed in the correct conditions. In extreme high or low moisture conditions, a floor can start to go through unsightly and unexpected changes and in worst cases, cause irreparable damage. Of which, in many cases, is not covered by the manufactures warrantees.

Here are a few things that can be done to help maintain the correct conditions in a home:

  • Have a way to monitor temperature and humidity in the home.
    • If the HVAC thermostat does not have the ability to read humidity, inexpensive tabletop units can be purchased at most big box stores.
  • If the levels start to go outside the zone; use a humidifier or dehumidifier to control the moisture levels.
    • Standard heating and air conditioning systems may not be effective at controlling humidity levels. Additional humidity controlling devices may be necessary.
  • Make sure humidity control devices are maintained and always working properly.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.


Quick links to products related to this episode…

Did you know Gehl Flooring Supply also provides underlayments, fasteners and adhesives for hardwood flooring installations? Check out our additional product offerings by clicking on the categorical menu bar at the top of this page.

‘Did You Know’ Episode 5 – Variation in Engineered Hardwood Flooring 

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Episode 5 – Variation in Engineered Hardwood Flooring

Wood is usually chosen as a flooring option because of the natural beauty, distinct color and graining characteristics. While a more traditional graded and sorted material is still marketed, a good amount of today’s factory finished engineered hardwood flooring is made from a live-sawn cut of the log (see Info Bulletin #150 for more information). Each board is unique in its characteristics and can vary in color and grain appearance from piece to piece. With all that beautiful variation, unfortunately a small sample board (even an 18” x 24” display panel would be considered a small sample), may not show all the variation the flooring could have. Below are a few reasons these variations can exist.

Natural Board Variation

In the above opening paragraph, we explained that the live-saw cut has become more commonly used to produce factory finished engineered hardwood. With this cut, the manufacturers can maximize the yield out of a log, allowing all color and grain differences. In most cases, there is little to no grading in this cut; you receive all the beauty the log provides. Each plank can vary from a clean to rustic visual and contain small to large filled knots and splits, sap wood, and a high contrast within the natural and lighter stained visuals. Texture variation can also exist depending on the surface treatment. If the collection has a wire-brushed texture, some planks may have more texture due to the density of that particular plank.

This can also vary by specie. It is important to take heartwood and sapwood into consideration before choosing your floors. The difference between the inner part of the tree (heartwood) and the outer part of the tree (sapwood) can be seen as variations of light and dark. The natural contrast between heartwood and sapwood plays a major role in the color of wood floors. Variations can occur from board to board, as well as in the same board. This occurs naturally, and is not an “unfinished” board. This sapwood is depicted in the Oak flooring image below. The Sapwood is light/yellowish mineral streak in the photo. Some species will have greater levels of variation, for example, Hickory or Maple. Two examples of specie variation are shown below.

Hickory Live-Sawn Factory Finished Engineered Flooring
Oak Live-Sawn Factory Finished Engineered Flooring

Natural Color Changes Over Time

The natural board subtleties may become more distinct over time due to exposure of direct sunlight. Exposure to UV rays from sunlight, florescent, LED and incandescent bulbs can change (patina) each board. Window coverings, UV resistant tint, solar screens can minimize but not eliminate this natural occurrence. Certain species are more susceptible to light and development of varying degrees/shades of patina, due to their high content of natural oils & tannins. Occasional rearranging furniture and rugs will help reduce the potential effects of the sun.

This color change is depicted in the image to the right. The darker section of the flooring had been covered by a rug. The lighter portion was uncovered. While this may eventually catch up, most homeowners may see this as a product defect when in fact, it is a naturally occurring scenario.

Older display panels that have gone through this natural change may be different from new flooring being delivered to the jobsite as the new flooring has not been exposed to the same conditions. In time, when exposed to similar conditions, the floor should catch up to the sample panel.

Regional/Seasonal Harvesting Variation

Many things can change the final color and grain definition of a cut piece of wood. From the length of a growing season, the soil a tree was planted in to the final cut of material from the log. With this, we experience differences in color and mineral streaking in our lumber depending where in the US or Europe the material comes from. As the increased demand of hardwood flooring continues, manufacturers may source their material not only from additional regions of the country, but possibly from all over the world. The graphic to the left is showing the possible variation in color depending on what portion of Europe a log may have been sourced from. This same regional variation exists in the US.

In addition to region, the time of year that the lumber was harvested can also change its color due to the amount of natural sugars and oils traveling through the tree at that particular time of year.

All the above scenarios can create a slight variation between batches of the same collection and/or color.

Fuming Characteristics

There are multiple ways manufacturers can accentuate the natural beauty of wood. Some manufactures utilize a process called Fuming. Fumed hardwood is a natural accelerated aging process used to enhance the dark to light subtleties within every wood plank, batch and region. The deepening in color and variation is created by adding a natural oxidizing agent in a controlled environment to react with the naturally present tannins in the wood – Time, Temperature & available Tannins (naturally present in the wood) mix to create one of kind planks that are added to the color options of a collection. While this process is done in a very controlled environment, it is not 100% precise. As mentioned in the previous section, Regional/Seasonal Harvesting Variation; every region, grove and tree produces an individually unique and high contrast color palette. This fuming process can accentuate that contrast. The finish system usually used with this process is natural oil which can cause additional contrast. Additional information regarding the different finish systems is explained in the next section.

The below image is an example of a natural oak vs. a fumed oak.

Natural Oak
Fumed Oak

Different Finish Systems

There are multiple finish systems that manufacturers utilize to create their collection of colors. Some finish systems can change the overall color of a floor as it ages or oxidizes. As mentioned above, some may start with a reactive type of coloring process like fuming, and then add penetrating oil to provide a two-tone or layering appearance. While this may provide the color and ‘raw’ appearance that has become popular, this finish system can come with inherent risks. A fumed, naturally oiled floor will have the most variation and can experience a large color change over time. Most retailers will purchase a box of flooring to sample to their prospective customer as their display sample panel may not show the overall variation well.

Another finish system would be a more traditional stain/urethane finish system. Some also utilize stains, glazing or tint coats in a urethane system to produce a layering effect similar to a fumed/oiled system that can be more consistent between batches. These systems can also minimize the color change due to UV exposure or oxidation. In these multi-layered urethane systems, they have a very low sheen to provide that ‘raw’ appearance.

So How Do We Sell Wood Flooring?

After reading this, you may be asking yourself, how am I supposed to sell wood flooring? Well, first off, knowledge. The whole reason this information bulletin exists is to help inform you about the natural varying beauty of hardwood flooring. Wood flooring is the most replicated appearance in other flooring types. From laminate to LVP, even ceramic tile has imitated the look of wood. But none will ever be able to claim the true natural beauty or variation that a real wood floor will have, as no plank and/or floor for that matter is really ever the same. Real wood floors will never have a repeating pattern across the floor. Continue learning about real wood floors by reading our other Information Bulletins or Did You Know Episodes.

Content for this episode (including some written content and images) was sourced from the websites of Naturale Elegance Flooring and Hallmark Floors. Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.


Quick links to the products mentioned in this episode…

‘Did You Know’ Episode 4 – Nailer Recommendation for Engineered Flooring

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Episode 4 – Nailer Recommendation for Engineered Flooring

Within many flooring companies, it has become standard to install laminated flooring with a 20 gauge flooring stapler or ‘floor runner’. While engineered flooring may sometimes be confused with being “laminated”, they are different materials and cannot be installed with the same fastener.

Most laminated floors are thinner (1/4” – 1/2”) and constructed of a composite material that may require a thin gauge staple so that the fastener does not telegraph into the face of the material. Engineered flooring is usually constructed of plies of plywood or sometimes fillets and glued together in opposing layers. The final material thickness can range from 3/8” to 3/4”. With this additional thickness, a 20 gauge flooring stapler that may be sufficient for a laminate floor will not have the holding power to properly fasten an engineered floor.

The main reason this is not a suitable fastener is because a 20 gauge ‘floor runner’ can only accept a staple length of 1”. Inserting a 1” staple at the industry standard of 45 degrees into a 9/16” flooring, you are only penetrating into the subfloor about a 1/16 of an inch. This is not nearly enough holding power to hold down hardwood flooring and will come loose from the subfloor when that floor goes through any seasonal changes.

A common recommended fastener for engineered flooring is an 18 or 20 gauge staple or cleat in a nailer that will accept a fastener length up to 1-1/2”. There are many manufactures that make a gun that will accept these fasteners. Two nailers we have seen to be very versatile are the Powernail 50P and 50F that are pictured below.

The 50P and 50F are 18 gauge cleat nailers that have many options, but one particular option that makes these guns versatile is the option to adjust the foot to the flooring thickness you are working with. The 50P is mallet actuated and the 50F a trigger pull, both will fasten flooring from 3/8” to 3/4”, utilizing a cleat 1” to 1-3/4” in length, allowing for the correct fastener penetration into the subfloor.

On the opposite side of this concern, using a standard hardwood flooring fastener (15.5 gauge staple or 16 gauge cleat) on engineered flooring may provide the correct subfloor penetration, but you will risk the fastener telegraphing through the surface of flooring.

As always, check with the installation guidelines of the material you are working with as most flooring manufactures have suggested guns to install their flooring. You may find that most recommend the 50P or 50F.

In addition to utilizing the correct fastener, you may also want to read one of our other episodes; Episode 1 – Adhesive Assist with Fastener to aid in the fastening of the wider engineered floors.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.


Quick links to the products mentioned in this episode…


Did you know Gehl Flooring Supply also provides underlayments for hardwood flooring installations? Check out our additional product offerings by clicking on the categorical menu bar at the top of this page.

‘Did You Know’ Episode 3 – The Cut of Wood

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Episode 3 – The Cut of Wood

All wood flooring is not created equally. From the differences in species, to the tree, to how and where it is grown, to where it is sawn and how it is dried, to how it is milled and manufactured, many important aspects can affect the performance and appearance of installed wood flooring. The way the wood is cut affects how it is dried, how it will look, and how it will perform in the home or office once it is installed.

For purely aesthetic considerations, the exposed grain is key to the character and look of the flooring. For performance considerations, the grain direction (whether running lengthwise, side-to-side, top-to-bottom, or across at angles) dictates how the wood will perform when exposed to humid or dry conditions.

Wood is a three-dimensional, anisotropic, and hygroscopic material.

A hygroscopic material is a substance that can absorb and retain moisture or lose or throw off moisture. Wood and wood products are hygroscopic. Wood expands with absorption of
moisture, and dimensions become smaller when moisture is lost or thrown off.

An anisotropic material refers to a substance that has different physical properties when measured in different directions. The shrink/swell properties and the strength properties of wood differ in every direction.

The angle of the annual growth rings changes the look of the floor, and it determines the dimensional properties, as well. The strain characteristics of each of these cuts of wood are affected by the grain angle, which describes the orientation of the growth rings with respect to the wide face of the board. These grain angles reflect the path in which the water moves through the wood. Wood will either shrink or swell depending on the moisture gained or lost.

The shrink/swell properties in wood are unequal along the three primary directions (longitudinal, tangential, and radial) of any piece of wood. Wood shrinks and swells the most circumferentially around the growth rings (tangentially), about half as much across the rings (radially), and only in minuscule amounts along the grain (longitudinally). The strength properties in wood also vary along these three primary directions.

There are seven cuts from which wood can be cut from the log and used for flooring, each of which has its own unique characteristics:

PLAINSAWN

Wood that is cut parallel to the growth rings so that the grain angle is from 0° to 45° to the wide face of the board (a tangential cut) is called plainsawn in hardwoods (flatsawn in softwoods). Plainsawn flooring is more dimensionally stable in thickness (radially) and less stable in width (tangentially). Tangential movement of wood is a measurement of the amount the wood shrinks or swells across the circumference of the growth rings. Average values for tangential shrinkage from fiber saturation point to oven-dry are between 5-15 percent for most species of wood.


QUARTERSAWN

Wood that is cut perpendicular to the growth rings so that the grain angle is from 45° to 90° to the wide face of the board (a radial cut) is called quartersawn in hardwoods (vertical-grain in softwoods). Quartersawn lumber is more dimensionally stable in width (radially) and less stable in thickness (tangentially). Radial movement of wood is a measurement of the amount the wood shrinks or swells perpendicular to the growth rings. Average values for radial shrinkage from fiber saturation point to ovendry are between 2-8 percent for most species of wood.


RIFTSAWN

Wood that is cut neither parallel nor perpendicular to the growth rings so that the grain angle is from 30° to 60° to the face of the board is known as riftsawn in hardwoods (bastard-sawn in softwoods). This cut is more stable than the plainsawn cut, but not quite as stable as a true quartersawn cut. Clearly, there is some cross-over between the angle of the cut for quartersawn and for riftsawn. These two cuts commonly are sold together.


LIVESAWN

Wood that is cut from the outside diameter through the heartwood incorporating the full range of the previous characteristics on the face of the board is known as livesawn material. This cut of wood is typically wider and incorporates all of the previously described dimensional stability and aesthetic characteristics of plainsawn, quartersawn, and riftsawn.


END-GRAIN

A cross-section of wood is cut perpendicular to the grain, or the surface exposed by such a cut. End-grain is wood that is cut so that the face of the board surface exposes the ends of the growth rings. This also is known as the transverse cut. End-grain flooring will shrink and swell according to the tangential value in the direction across the circumference of the growth rings, with essentially no movement in thickness.


SLICED VENEERS

Sliced veneers are used exclusively for engineered flooring and decorative panels. With sliced veneers, the log is cut into a block called a cant, or sometimes halved into what is called a flitch, which is drawn across a very sharp-angled blade. The process is repeated until the whole cant has been turned into a pile of high-quality veneers. The appearance of sliced veneer is similar to sawn lumber and will have the same natural, physical, and strain characteristics. However, the slicing process has thickness limitations and can stress the wood fibers, resulting in knife checks.


ROTARY-PEELED VENEERS

Rotary-peeled veneers also are used exclusively for engineered flooring and decorative panels. With rotary-peeled veneers, full logs are positioned on a large lathe and spun against a sharp blade. The log continues to spin until the entire log has been turned into a pile of veneers. This technique produces the least amount of waste. Rotary-peeled veneers have a distinct, purely tangential grain pattern. The grain pattern will repeat on wide sheets. However, the peeling process has thickness limitations and can stress the wood fibers, resulting in lathe checks.


All wood flooring is not created equal. From the differences in species, to the tree, to how and where it is grown, to where it is sawn and how it is dried, to how it is milled and manufactured, many important aspects can affect the performance and appearance of installed wood flooring. The way the wood is cut affects how it is dried, how it will look, and how it will perform in the home or office once it is installed.

As nice as it sounds to be able to use this information to completely understand and predict how wood will perform, we must remember that wood is a natural resource that grows irregularly and is exposed to seasonal fluctuations through its lifetime. Wood grows in different soils, and can be exposed to different minerals within the same region. No two trees from the same species are identical, nor are two boards from the same tree identical, and properties can vary even within one individual plank of wood.

After species selection has been made, the next discussion item should be wood cut performance characteristics. This discussion with the end-user should be simple. When aesthetic considerations are less important than performance considerations, use the following general talking points:

• Narrow strips shrink and swell less than wider planks. The wider the plank, the more potential there is for dimensional changes in the wood.
• Quartersawn flooring is the most dimensionally stable cut of wood. Riftsawn flooring would be a good second choice.
• When hardness is the most important factor, end-grain is the hardest option. In general, end-grain may be 1.5x harder than the same board in the plainsawn cut. The next hardest cut would be quartersawn or riftsawn cuts.
• Engineered wood flooring generally is more dimensionally stable than its solid counterpart. If you were to then place the most stable cut of wood on an engineered platform, you will have a very dimensionally stable plank of wood.

How wood is cut from the tree plays a critical role in so many variables, including how the finished floor will look, how the floor will perform, and what the floor can withstand over time. When making the final selection of what wood floor should go into the home, one of the most important factors to consider is the cut.

Written by Brett Miller, October 1, 2021. Brett Miller is the vice president of technical standards, training, and certification for the National Wood Flooring Association and the technical editor of Hardwood Floors magazine.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.


Did you know Gehl Flooring Supply provides Unfinished and Prefinished Solid Flooring and Rubber Sports Flooring to our industry? Check out our additional product offerings by clicking on the categorical menu bar at the top of this page.

‘Did You Know’ Episode 2 – Seasonal Gaps and Moisture Control

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Episode 2 – Seasonal Gaps and Moisture Control

Even though wood has been cut, dried and milled into flooring, it is still a hydroscopic material and can accept and release moisture. When doing so, it can expand and contract. In extreme high or low moisture conditions, a floor can start to go through unsightly and unexpected changes and in worst cases, cause irreparable damage. The graph below can provide a good understanding of this comfort level.

As you see in the information below, the Forest Products Laboratory states that the comfort level of wood is at 60° – 80° and 30% – 50% relative humidity. These levels have been adopted by the National Wood Flooring Association and most flooring manufacturers as the levels at which hardwood flooring products will perform best. With this understanding of where wood performs best; manufactures have set their warrantee programs to mirror these levels.

When flooring is exposed to extreme conditions, either high or low, it will start to expand (when wet) or shrink (when dry). At this point, the floor may start to show evidence of these extreme conditions. Keeping your floors outside of the above mentioned parameters for an extended amount of time may cause irreparable damage. In many cases, exposing wood flooring to levels outside of this zone will void the manufacture’s warrantee.

Here are a few things that can be done to help maintain the correct conditions in a home:

  • Have a way to monitor temperature and humidity in the home.
    • If the HVAC thermostat does not have the ability to read humidity, inexpensive tabletop units can be purchased at most big box stores.
  • If the levels start to go outside the zone; use a humidifier or dehumidifier to control the moisture levels.
    • Standard heating and air conditioning systems may not be effective at controlling humidity levels. Additional humidity controlling devices may be necessary.
  • Make sure humidity control devices are maintained and always working properly.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.

‘Did You Know’ Episode 1 – Adhesive Assist with Fastener

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Episode 1 – Adhesive Assist with Fastener

Hardwood flooring is manufactured in many widths and cuts to provide a multitude of design opportunities per species of hardwood. One of which is wide plank floors 4” and greater and is chosen for the beauty and presence it brings to a room. Depending on the situation, you may be installing prefinished or site finished; engineered or solid flooring to meet the design the customer is requesting.

In most situations, utilizing the correct cleat or staple may be sufficient to fasten the flooring to the subfloor. This is evident in the manufacture’s installation guidelines as they may not recommend any additional holding of the flooring in addition to their recommended fastener.

Parts of the country see more extreme temperature and humidity swings between the summer and winter months. If correct living conditions are not maintained in the home, the flooring may be stressed and you may start to see unsightly gaps, fasteners starting to work free from the subfloor and possible cracking and popping sounds as you walk across the floor (see Info Bulletin #20). The best way to minimize the possibility of this happening is to add an adhesive assist to the fastening method. From the manufactures point of view, this extra holding power may not be necessary for the country as a whole but can be added security for a successful installation on jobs where these drastic swings in the climate exist.

An adhesive assist can be achieved in two different ways. The main goal is to add additional holding power in addition to the mechanical fastener. Below is a quick description on the ways to achieve this:

Option 1

Using a hardwood flooring elastomeric tube adhesive (like these or equivalent) applied in strips onto the subfloor or the back of each board prior to nailing in each row. The NWFA lists a few common application methods. Choosing one of the methods from the below image will add additional holding power to minimize the possibility of squeaks, crackling and popping as the floor goes through seasonal changes.


When using the glue-assist method, you will no longer be able to install a traditional sheet-good vapor retarder. When nailing down wood flooring over a conditioned space that is maintained at the same conditions as the living/interior space, no vapor retarder is necessary. Wood floors installed in these conditions may be nailed with a glue-assist directly to the subfloor without use of a vapor retarder. Where wood flooring is being installed over unconditioned space, use of a liquid-applied, or similar Class II vapor retarder that is compatible with the flooring adhesive may be used to allow for a glue-assist directly to the subfloor.

IMPORTANT: When using a trigger-activated flooring nailer with the glue assisted installation method, the installer must either stand on the floor, or apply a downward pressure to the surface of each board as it is being nailed. This will ensure the flooring does not lift away from the subfloor causing unnecessary vertical movement or hollow noises.

Option 2

Using a full spread method utilizing a hardwood flooring adhesive. With this method, you would not need to use the standard adhesive trowel size that would be required to perform a full glue down application as you also have fasteners assisting the installation. A smaller notch trowel would be sufficient as long as you maintain the standard fastener schedule. This method also requires the removal of the paper vapor barrier. Your adhesive will act as the vapor retarder.

One of the above mentioned adhesive assist methods can be used on any hardwood flooring, solid or engineered and best used when the width of floor exceeds 4”. Even with the added holding power this may offer, the floor owner will still have to maintain correct temperature and humidity conditions for best performance of their floor and to maintain the manufacture’s warrantee.

Additional information can be acquired from the manufacturer’s technical department of the products used on your floor. The National Wood Floor Association (NWFA) can be an additional resource. They can be reached at 800-422-4556 or online at www.woodfloors.org.

Quick Links to the products mentioned in this episode…