How to Install Hardwood Floors

When it comes to new flooring, there’s nothing like the timeless warmth of solid hardwood flooring. It can complete any home design or remodel, whether the living room, hallway, or bedrooms. As a home improvement project, installing hardwood floors may be easier to tackle than you might expect.

To help get your hardwood flooring installation project started, we put together a guide to answer your top questions about how to install hardwood floors and walk you through the entire project. Whether you’re hiring a contractor or doing it yourself, we’ll show you step by step what to expect and how to install solid hardwood floors.

What to Look for When Choosing Your Hardwood Flooring

One of the first considerations for planning the installation of your hardwood flooring is the location and type of subflooring in the room that the hardwood floor is to be built on. Given hardwood floor installation costs, it’s better to protect the investment by choosing the appropriate flooring type for the location conditions.

Because hardwood floors are susceptible to damage when exposed to moisture, solid hardwood should only be installed on grade or above grade. Below grade floors are those levels of the home that are built below the ground, even by as much as 4” below the surface. These areas are cooler and contained, creating moisture buildup. If there’s a possibility that the flooring is below grade, consider utilizing engineered hardwood rather than solid hardwood flooring.

Another location concern when looking at how to install hardwood floors is the sub-floor. Hardwood floors should be installed over an existing wood floor foundation, or a plywood subfloor. For solutions to how to install hardwood floors on concrete, the most efficient way is to plan to first install a ¾ CDX plywood subfloor. This adds some degree of soundproofing and cushioning, as well as provides a secure anchor point for the hardwood flooring.

To reduce echo and other noise over large areas, especially over concrete slab floors, it helps to install a sound barrier under the floor, which can only be done by installing a floating floor. Puncturing the soundproofing flooring underlayment with installation nails required to install solid hardwood flooring reduces the effectiveness of the sound barrier.

As a result, consider using engineered hardwood flooring in place of natural, untreated wood flooring in these locations. Engineered hardwood flooring can be installed as a floating floor over the solid concrete, and is more durable in high humidity areas. If the floor is below grade, or if it is a concrete slab floor, engineered hardwood flooring offers a moisture-resistant fit that also provides sound proofing.

Hardwood Variety

One of the advantages of solid and engineered hardwood flooring is the selection available to customize your floor to meet the style of your home. This includes the color and grain, the width of the planks, and the durability of the wood species against the demands of the location and the household traffic.

Keep in mind that softer wood species can be more easily scuffed or scratched in high traffic areas, especially in homes with pets. Be careful when choosing the hardwood flooring species to match its strength and durability with how the area will be used. For instance, white pine flooring offers a unique and attractive design, but it is one of the softest wood species, while other pine woods are among the strongest. The individual species will be more resilient and may be treated or finished in different ways, which may impact the price.

The color of the flooring can influence the visual size of the room, making it appear larger or smaller. Similarly, the width of the planks that make up the floor can appear to take up more or less space and influence how open the room feels and looks. Recent trends have shown that wider planks are gaining in popularity, but the classic 3” or 4” width planks provide a timeless look and a durable, solid floor.

Prefinished vs. Site-finished

The hardwood floor installation cost is also influenced by the finish on the planks. One of the advantages of solid hardwood flooring is that the floor can be refinished to restore the surface shine, so the planks once installed can be sealed at any point. Before installation, you’ll have the choice between prefinished planks or unfinished, site-finished planks.

If you’re concerned about how long it takes to install hardwood floors, prefinished hardwood planks minimize the project time. With prefinished planks, your floor is ready to walk on and even place furniture on after the last plank is fit in place. A prefinished hardwood floor provides planks that are shaped, finished, and sealed against scratches, scuffs, and spills before they arrive on site. The board edges are beveled, creating slight groove lines in the finished floor. There is less mess from sanding and no chemical smell lingering in the room.

With site finished hardwood, the floor is installed and in place before being sanded, treated, stained, and sealed. It produces a flat floor, with no beveled edges on the planks, that fits edge to edge, flush and smooth, because all planks are sanded at once. This is an extra process after installation is complete and can add up to a week to the project.

When budgeting how much to install hardwood flooring, add the extra days of work for sanding, staining, and sealing a site-finished floor to the anticipated costs. Additional costs come in the form of materials, such as the chemical stain and sealants, as well as the specialized tools such as the floor sander, which may need to be purchased or rented if you are installing the floor yourself.

Protect Your Flooring Choice

When choosing hardwood flooring, it’s a good idea to look for flooring products that come with a guarantee of quality. Find hardwood flooring bundled with warranties to ensure satisfactory finishes free of structural defects. The warranties may range in time periods, from only covering the installation, to warranties that last a decade or more. A solid warranty will add to the cost of the flooring, so make sure to read the fine print before you choose, and know ahead of time what will be covered.

Before Installation

If you’re wondering how long does it take to install hardwood floors, keep in mind that every project is different, which influences the amount of time it may take to complete. An important factor is to make sure the project is properly planned and prepared before it gets started.

When planning how to install hardwood floors, start with square footage. This requires taking accurate measurements of the floor area to be covered, allowing for grade and shape changes, such as stairs, closets, or hallways. 

• To do this, determine the square footage by multiplying the width by the length of the room, either as a whole or in square sections. 
• Measure each room or room section individually. 
• Add the square footage totals together.

To account for damaged planks and cutting errors, it is recommended to add a “waste factor” of 5 to 15% to the total square footage. With a more complicated flooring pattern layout, such as a diagonal pattern as opposed to the usual perpendicular layout, more cutting will be required, which means there will be more waste created. Plan ahead and always order more flooring than needed before the start of the project. Extra bundles can be returned, or can be kept for future additions or repairs.

Another key consideration in how to install hardwood floors is planning where to start. When flooring multiple rooms, it’s best to start in the hallway that connects them. The planks in a hallway should always run the length of the hall, to ensure better stability and reduce the amount of waste cuttings created. It also creates a seamless transition space in the doorways and other open areas to encourage consistent placement and pattern layout for the whole project.

The final preparation stage, once you have the wood flooring ordered and delivered is to allow the planks to acclimate to the location over a period of five days. Stack the planks on the subfloor in the room where they will be installed and try to keep the room’s temperature between 65 and 75 degrees fahrenheit. The wood naturally expands and contracts with the moisture in the air, and laying the planks out to start adjusting to the room’s humidity is an important first step in how to install hardwood floors.

Hardwood Floor Installation Requirements

As with any home improvement project, it’s important to gather the necessary tools and equipment before starting.

Required Protective Gear

• Knee pads
• Safety glasses/goggles
• Work gloves
• Ear protection
• Safety mask

Required Flooring Materials

• Solid hardwood flooring
• Vapor barrier, paper or felt
• Spacers
• Floor molding and baseboards
• Flooring transitions
• Finishing nails
• Wood Putty
• Wood Glue

Required Tools

• Tape measure
• Nail gun/Pneumatic flooring nailer
• Staple gun
• Circular saw or table saw
• Hammer
• Pry bar
• Utility knife
• Nail set
• Mallet and block
• Chalk line
• Mason’s line

Prepare for Installation

If it’s an original wood floor of ⅝ CDX wood flooring or better, the new flooring can be installed using the existing wood floor as a subfloor. If using an existing wood floor as the subfloor, prepare the floor by cleaning it thoroughly and removing any debris, or sanding out imperfections that may influence the fit of the new flooring. 

• Replace broken boards.
• Take care of squeaks or weak spots by nailing the loose board to the joist below, to tighten it in place and strengthen it. 

Otherwise, the first step to prepare for installing a new floor, if replacing an older one, is to remove any existing floor boards. This includes removing any base molding or transition molding around the edges of the room. 

Make sure the floor is completely level and clear of debris. 

• Sweep or vacuum the subfloor and keep it clean. 
• Make sure shoes are clean before walking on the subfloor.
• One method of keeping the floor clean as you work on the flooring is to tape plastic over doorways. 

Mark the walls to show the location of the floor joists under the subfloor.

Next, use flooring underlayment to create a slip-sheet layer to reduce the friction between the final flooring and the subfloor. 

• Use cork or foam underlayment, felt paper, vapor barrier, or red rosin paper to cover the subflooring. 
• Make sure it says flat, and overlap the layers at the edges. 
• Attach the barrier layer to the subfloor using a staple gun. 
• Snap a chalk line from wall to wall to mark where the joists are along the floor, over the barrier paper.

Starting on the longest wall, working perpendicular to the floor joists, measure out from the wall the width of a floorboard, adding ¾ inch for the spacers. Mark the distance with a nail at each end of the wall and attach a mason’s line between the nails as a guide for laying down the first row of wood planks.

Design the Flooring Layout

The next step in installing a hardwood floor is to lay out the planks across the floor, mixing and matching in colors and board lengths to randomize the floor’s design. This is known as “racking the boards” and it prevents groups of repeated colors or grain print from showing up in patches across the floor. 

To rack the boards, remove the planks from the bundles they arrived in. 

• Arrange the boards by similar lengths, shades, or grain patterns. 
• Separate any damaged, curved, or unusable pieces and set them aside to use at the ends or as filler pieces.
• Pull from the groups one plank at a time to create a unique, random flooring layout that suits the room. 

Once the plank order is determined, lay the pattern out over the floor to check for pattern consistency and fit. 

• Avoid repeating the pattern too close between sections of the room.
• Offset the board length and width to add variation and stability across the floor. 
• It’s a good idea to place the widest boards at the wall edges for the best visual effect on the design. 

Measure the planks that will need to be cut at the ends of the room. Use a table saw or circular saw to make the cuts. Clean up the edges using the utility knife if they fit too snug. Use the cut boards for the end pieces to hide the rougher, cut edges under the baseboard once the flooring is finished.

Install the Flooring

Place spacers against the wall to allow the wood flooring to expand over time. Allow for ½ inch expansion on the ends of the boards, and use ¾ inch expansion spacers to block the boards that run parallel along the length of the wall.

To begin the installation, place the first boards against the spacers, with the tongue side facing into the room. Tap them into place end to end along the wall.

• For the first row of boards only, pre-drill nail holes ½ from the wall, every 6 to 10” along the board, or at the joist points.
• Nail the boards in place with finishing nails, attaching them to the subfloor. 
• Countersink the nails by setting the nails slightly below the surface of the board, using a nail-set or tapping the nail below the surface using another nail and a mallet.

Every 6” to 10” along the boards, drill pilot holes and then nail directly through the board tongue at a 45-degree angle, called blind nailing. Blind nailing allows the board to be nailed to the subfloor without interfering with the tongue-and-groove connection of the other floorboards. Countersink the nails.

Lock the second row of board planks along the first. Tap them in place using a mallet and block to secure the tongue-and-groove connection. 

• Be sure to stagger the ends of the rows to offset each board length. 
• Use the different length boards at the ends and make sure to maintain the expansion gap on each end of the room.

Blind nail the second row of planks into place. Repeat the process until the planks are far enough from the wall to use a flooring nailer. Pneumatic nailers tend to be larger and take up more space to position and use, so expect to work four to six rows of planks by hand.

Use the pneumatic nailer for the remainder of the room, working one row at a time. Follow the operation instructions of the nailer for safest use.

 For the last few rows, the boards should be nailed into place by hand again. Leave enough gap on the ends of the final rows to allow for expansion. 

The last row of boards may need to be cut lengthwise and trimmed to fit. 

• Measure from the board edge to the wall and find boards to fit the remaining space, without including the spacers or the board tongue edge. 
• When splitting the boards, make sure to trim up the correct side to match the grooved connection pieces to the already installed floor. 
• Glue the tongue of the boards into the split grooved edges to create a flat forward edge to the final row of boards. 
• That edge should meet the wall snug, and it may require using a pry bar to set the last pieces.

To Finish Up the New Hardwood Floor

For the final steps to installing the hardwood floor, make sure to countersink all face-nails along the floor and fill the nail holes with wood putty that matches the floor coloring. Replace the baseboards and other flooring parts around the walls and transition points as needed.

For prefinished flooring, the only remaining task is to sweep the floors of the construction debris and let the putty and wood glue dry. The floor can be walked on and furniture placed once the floor is cleaned.

With site-finished planks, the floor will need to be sanded down to a uniform, flat surface, stained, and then sealed. The process takes a few days due to the necessary drying time between the different layers of chemicals.