Engineered Flooring Installation
Engineered Flooring Nail-Down Installation
Thank you for purchasing your floor with The Fantastic Floor. Please follow these
installation procedures exactly to ensure the successful installation of your new hardwood floor. These procedures are written with an experienced
installer audience in mind, so if you require more information on the basic procedures of installation, we encourage you to contact the NWFA for more
information at www.nwfa.org or by phone at 1-800-422-4556.
Please note that hardwood flooring manufacturers provide their own
instructional materials for their products,and that these guides should be followed exactly and take precedence over this installation guide.
Inspect all materials products prior to installation. DO NOT install defective materials. Wood is a natural product with natural color variations, grain variations,
and tone variations. Though products do undergo a rigorous inspection process before leaving the plant, it is still necessary to inspect the materials in order
to ensure their quality. Installation of defective materials could result in voiding your warranty.
Order of Installation
In order to ensure that no damage is done to the wood over the course of construction, particularly in the case of homes
under construction and renovation, wood flooring should always be installed after all other installations are finished. Additionally,
foot traffic should be kept to a minimum after the installation of the floor is complete. If a protective cover is placed over the floor
at this time, make sure that the entire floor is covered as many woods are sensitive to light and will undergo color change, creating a
Crawl Space and Subfloor Specifications
Before installation, ensure that all basements and crawl spaces are dry. The crawl space also needs to allow for at least 18 inches between the joists and the ground. A vapor barrier/retarder has to cover 100%
of the crawl space, with the joints of the vapor barrier overlapping at least 6 inches. The vapor barrier itself should extend six inches up the stem wall,
where it must be attached and sealed. Finally, there must be a constantly operating mechanical exhaust and perimeter wall insulation or conditioned air supply with insulation.
Wood sub-floors must be secured with screws or nailed. Nails need to be ring shank and screws must be counter sunk. In the event that the wood sub-floor is less than 3/4’’ thick, add a single cross layer with a
minimum thickness of 5/16’’ for a total of 1’’ inch of thickness in order to combat possible squeaking after installation. There must be no oil, existing adhesives, wax, grease, urethane, dirt, varnish, paint, etc.
on the wood subfloor. Particleboard is not a possible sub-flooring option for staple or nail down installation, but it can be sufficient for a glue down installation. Subfloors can not possess a moisture content of over
12%. Additionally, the hardwood flooring’s moisture content and that of the subfloor can not have a difference of more than 4%.
Protecting Hardwood Prior to Installation
It is paramount that the wood is not delivered or stored at the site until the building is enclosed, as storing wood in these conditions will cause adverse effects as a result of fluctuating outdoor humidity and temperature
values. Once the building is enclosed, don’t bring or install the wood into the house until it has been brought to the temperature and relative humidity that it will kept at with the future occupants present. Additionally, don’t
deliver or install the hardwood until painting of primer coats, drywall, texturing, masonry, and concrete is finished.
For the different grades of a house, there are different restrictions for which types of hardwood can be installed. For above-grade and on-grade installation, engineered hardwood, solid hardwood, and a floating floor are all
acceptable. However, at below-grade, only floating floors and engineered hardwood are options. Should the ground around a building be 3 or more inches above the floor of that level, that level is considered below-grade, and thus
ineligible for solid hardwood.
Acclimating Hardwood Flooring
Preparing the Wood
Acclimating Hardwood is often an essential task for ensuring the wood doesn’t undergo any unforeseen dimensional shifts after or even during the installation. While acclimating, make sure not to store hardwood in a location
where the temperature and humidity is not that of the living space within the house, such as a garage or exterior patio. Preferably, the house should have all of the heating, ventilation, and air conditioning systems running for
at least five days before the hardwood arrives for acclimation.
Checking Boards’ Moisture Content
The relationship between the moisture content of the hardwood boards and that of the subflooring determines whether or not the wood is acceptable for installation. In order to ascertain these moisture values, check various boards’
moisture content, approximately 4 boards for every 100 square feet. If the wood is solid and wider than 3’’, then there should be no more than a 2% difference between moisture content of the wood after it has acclimated and the subflooring.
With hardwood that is narrower than 3’’, the difference between the moisture content of the hardwood and the subfloor should be no more than 4%.
As a general rule, wood floor maintains dimensional stability best within a temperature range of 60-80° Fahrenheit and a humidity range of 35-65%. The two exceptions to this rule apply to imported and exotic wood species, as they may react differently
to these circumstances, and extreme geographical circumstances.
Processes of Moisture Testing
Subfloor Moisture Testing
In order to get an accurate reading of the sub-floor’s moisture level, test approximately 2 locations per every 100 square feet and take the mean average of these values. If there is an unusually high value in one particular region, this probably indicates
a problem which should be attended to prior to installation. There are various moisture tests that can be performed to determine whether moisture levels are acceptable for installation. The acceptable moisture conditions for installation are:
- Moisture readings of less than 14% when using an equivalent moisture meter on wood substrates.
- Calcium chloride test producing results of less than 3 pounds/1000 square feet/24 hours.
- A reading of less than 5.0 on a Concrete Moisture Counter.
Vapor barriers for hardwood and wood sub-floors are sometimes referred to as vapor retarders. They can be a membrane, vapor resistant material, or covering with a vapor resistance rating at or above .7 perms, or at or below 50 perms. They are effective at
alleviating moisture problems by protecting the hardwood from ground moisture and condensation. They also provide a number of other benefits, including noise reduction, dust reduction, and the elimination of wood-on-wood contact.
However, different vapor barriers work more effectively than others in given circumstances. In the case of a wood subfloor, an impermeable vapor barrier with a rating of .7 or less shouldn’t be used. With this level of impermeability,
the vapor barrier could possibly trap moisture in or on the wood subfloor.
In the case of a concrete subfloor, there are a variety of methods to test its moisture, including calcium carbide testing, calcium chloride testing, or relative-humidity testing. Before testing, the concrete is required to be at least 30 days old.
Various retailers provide concrete moisture meters and relative humidity kits. You can contact the NWFA to find a retailer near you at 1-800-422-4556. Unfortunately, these tests cannot guarantee a concrete slab that is completely free of moisture all year-round.
The vapor barrier specifications for a concrete subfloor diverge from the wood subfloor specifications by requiring a very high level of impermeability at .15 perms or lower, allowing for little or no moisture movement.
Engineered flooring is very versatile, able to be installed below-grade as well as directly onto concrete or sub-flooring. There are three types of engineered floors we will address here: Nail-down floors, floating floors, and glue-down floors. Whatever method you
choose to install your flooring, make sure to follow all specifications and guidelines set by The Fantastic Floor, your hardwood manufacturer, and, in the case of glue-down flooring, the adhesive manufacturer. Engineered flooring can be installed over radiant heat under the
proper conditions, but the heat must be turned off during installation.
Nail-Down Engineered Flooring
The first step to installing either a nail-down engineered floor or a free-floating engineered floor is to install a 6-mil polyethylene layer over the sub-floor. This protects against moisture rising up from below and also helps prevent squeaking. Install the vapor
barrier parallel to the direction of the flooring. Make sure that the vapor barrier has a 3’’ overhang around the perimeter, and that it overlaps each previous run by at least 6’’.
Take boards out of several boxes in order to ensure good tonal variety and mixture in the floor. Lay your flooring at a 90° angle to the floor joists whenever possible. Using an external wall as a reference, snap a working line parallel to the reference wall, allowing
for the requisite expansion space indicated by the wood’s manufacturer.
Put down a row of planks that runs the along the length of the working line. Make sure the tongues are always facing out as using the tapping block on the plank’s groove could damage the board. Blind nail and top nail the first row, while being sure to use only the
appropriate fasteners. Research the specie of wood you’re installing to determine whether or not it will require pre-drilling in order to nail it down. The latter rows should be blind nailed whenever possible. Attempt to nail the boards into joists whenever possible.
Nails should be 1-2’’ from the ends of the boards and every 4-6’’ along the edge of the boards, going in at a 45° angle.
Make sure to stagger your boards such that no two end joints are within three rows or 6’’ of each other. Once installation is complete, use appropriate trim moldings and wall moldings along walls and doorways to cover edges and conceal gaps resulting from any
irregularities in perimeter dimensions. Use a flooring filler to fill in any wide seems along joints that blends with the tone of the wood. Afterwards, clean the floor with a recommended hardwood flooring cleaner.
Glue-Down Engineered Flooring
In order to begin installation of a glue-down
engineered flooring, the first step is to evaluate the substrate to determine whether it is within acceptable moisture content with regard to the adhesive and wood manufacturers’ recommendation. Try when possible to install the flooring at right angles to the floor joists.
Finally, make sure you are using an adhesive approved by your flooring’s manufacturer.
To begin, using an external wall as a reference, snap a working line parallel to the reference wall, the width of the board, plus the tongue and the recommended expansion space. Use an appropriate trowel, measuring approximately 3/16’’x1/4’’/1/2’’ v notch, and apply the
adhesive with the trowel at a 45° angle for the first row of planks. Put down a row of planks that runs along the length of the working line, ensuring that the first row is firmly seated in adhesive. This is important as the subsequent rows will be pushed back into this first row.
Always lay the planks with the tongue facing out, as tapping the grooved side of the plank with the tapping block can potentially damage the board. Make sure to stagger your boards such that no two end joints are within three rows or 6’’ of each other. When placing boards, interlock
the end joint first, as close to the side tongue-and-groove as possible, and set the board in place so as to avoid dragging the board through the adhesive below. Blue tape should be used to hold the boards together. Be sure to remove the tape within 24 hours and to use mineral spirits
or adhesive remover to remove the remaining adhesive. Failure to do so will result in dried adhesive damaging the finish on the flooring. Once the floor is installed, cover with a breathable material for protection from light and foot traffic. Use appropriate trim moldings and wall
moldings along walls and doorways to cover edges and conceal gaps resulting from any irregularities in perimeter dimensions. Use a flooring filler to fill in any wide seems along joints that blends with the tone of the wood. Afterwards, clean the floor with a recommended hardwood flooring cleaner.
Floating Engineered Flooring
When laying an engineered floating floor, having a level and flat subfloor is of the utmost importance. Of equal importance is testing the substrate for excessive moisture. Additionally, confirm before installation that the subfloor falls within acceptable moisture levels with regard to
the recommendations of the manufacturer. Install a vapor barrier as per your manufacturer’s specifications. Cover the subfloor with foam underlayment with a built in moisture barrier. Snap a working line parallel to the reference wall, the width of the board, plus the tongue and recommended
expansion space. Make sure to stagger your boards such that no two end joints are within three rows or 6’’ of each other. Once installation is complete, use appropriate trim moldings and wall moldings along walls and doorways to cover edges and conceal gaps resulting from any irregularities
in perimeter dimensions. Use a flooring filler to fill in any wide seems along joints that blends with the tone of the wood. Afterwards, clean the floor with a recommended hardwood flooring cleaner.