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Installing Prefinished Hardwood Floors

Construction How-To, Flooring Installation, Floors, Hardwood, Projects September 23, 2015 Sonia



 

 

 

 

 

 

 

By Larry Walton

Photos by Tim Walton

My wife and I love hardwood floors but we do not love living in a remodel while we’re installing or refinishing hardwood floors. We know this because we’ve done it a number of times.

One of the big advantages of full-thickness hardwood floors is the option of sanding and refinishing the floors in the future if the floor gets damaged, which is likely with me and my dogs.

We wanted a traditional 3/4-in. thick tongue-and-groove hardwood floor without all of the sand-in-place dust and the added hassles that come with applying the finish. We found some prefinished maple flooring at the local home-improvement center that looked like it would work well for our application. We have now had these floors in our house for a couple of years, and they’re performing better than we expected.

From a woodworker’s perspective, I knew that this flooring would have to fit tightly and flat to work, because “prefinished” meant no possibility of floating and sanding the gaps and elevation differences like traditional unfinished hardwood floor. The manufacturer did several things to pull this off.

First, they made the boards relatively narrow which helps the installer pull slight curves in line. It’s likely they took extra care in cutting any curved materials into shorter pieces to make them all as straight as possible.

Next, the manufacturer kept very precise tolerances for board thickness and for milling the tongue-and-groove profiles. We could tell this because the boards laid up to a very flat surface when installed. This is noticeable to someone who has installed raw hardwood and encountered the occasional slightly thicker or thinner board. Normally these discrepancies can be sanded out of traditional hardwood, but prefinished boards must match up better because they cannot be sanded flat.

It is wood, however, which is why they included a slight chamfer along the edges of the boards. The purpose of the chamfer is to accentuate rather than hide the joints. This feature covers up slight discrepancies in the board thickness and any small gaps where the boards join.

Another aspect unique to prefinished hardwood is the need for colored putty to fill holes where the boards cannot be blind-nailed through the tongue. We mixed different colors of putty together to create several shades so we could match exactly the color right where the nail hole was.

One of the big advantages of 3/4-in. hardwood is that it has enough structural integrity to bridge over small cracks and holes in the subfloor. (You must still make sure that moisture cannot get to your new floor.)

When starting the first row of flooring, make sure you are square with other important features in the room. In our case, the first room we installed was pretty forgiving because of the perimeter features, but this floor would eventually tie into the hallway, and the hardwood there needed to be in line with the walls. Because of this, we used a string line centered in the hallway to determine the alignment in our first room.

Of course, one of the best things about installing prefinished floors, in addition to avoiding the dust and vapors of the finish, is the fact that you can start using the floor as soon as you nail it down.

Step By Step

After pulling up the old carpet and pad, we removed the carpet tack strip and base boards.

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A floor scraper speeds up the process of removing carpet-pad staples and tack-strip nails. Since an adjacent vinyl area had double underlayment, we decided to leave this single layer of under-layment and make sure it was thoroughly nailed down.

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A pull saw, which has a thin blade, is a good tool to trim off casings and door jambs so the new flooring can go under the casings and door jambs. The cut is made by laying the saw blade on a scrap of the flooring to get the right height.

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We found some areas in the underlayment that seemed to be favored as a pet’s bathroom spot. One of my favorite sealers against stain and odor is this old fashioned shellac, which can be painted on with a brush.

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We face-nailed the initial row of boards to keep it lined up with our layout mark.

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After the initial row, we blind-nailed the subsequent rows through the tongue at an angle with a 16-gauge finish nailer until there was enough rows to allow the use of a flooring nailer.

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Occasionally, when we doubted that tongue-nailing would close the gap, we used a wood scrap as protection so we could hammer the next board into place.

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The flooring nailer was rented from a home-improvement center.

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A quick way to mark an end piece for cutting is to turn it around (tongue against tongue) and mark the board to be cut at the end of the finished surface of the previous board. When it is turned around (tongue against groove), the cut will be on the wall end.

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We usually keep a miter saw on the floor near the boards being installed. Once enough flooring is installed, we sweep up the sawdust and move the saw onto cardboard on the finished floor.

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A framing square and a Sharpie were used to mark the layout for a furnace vent opening. Don’t go only by the opening in the floor. There are some standard opening sizes that best match the available vent covers. Choose and cut the one that is closest to your rough vent opening to make sure the opening in your new wood floor will be covered by the louvered vent cover.

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I used the end of my finger as a depth gauge to lay out marks parallel to the edge of the flooring board.

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Because the layout marks are on the finished surface of the flooring board, we used a laminate style jigsaw blade (which pointed away from the saw) to make the cuts. This prevents tear-out on the finished surface. We also put masking tape on the jigsaw base to avoid scratching the floor surface.

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For this type of blade, the orbital setting on the jigsaw should be set to zero so the blade moves straight up and down.

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When using a reverse jigsaw blade for hardwood, we make sure to use steady downward pressure to keep the saw from chattering.

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When we reached the other side of the room, we again ran out of space to use the flooring nailer and switched back to the 16-gauge finish nailer through the tongue for as many rows as possible before shooting through the surface. Because the flooring is prefinished, surface nailing should be kept to a minimum. In the photo, note the flooring scrap extending the force of a pry bar into the piece being nailed. This is a good way to close the gap. Scrap lengths can be shortened as rows are added.

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The new hardwood floor is ready for immediate use. No sanding, no drying, just add furniture.

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We mix together a variety of shades of color putty to fill the nail holes where we had to surface-nail the flooring. The putty does not get sanded or stained, so the color match is important.

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A slight bevel along the edges of the flooring accentuates the joints and helps hide minor cracks and differences in elevation.

Side Note 1

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We start removing baseboard from the middle by shoving a stiff putty knife between it and the wallboard. Next comes a pry bar to gain more gap. Apply pry-bar pressure to the wall at floor level, where the wallboard will be backed by the house’s floor plate. Grab the baseboard in the middle and pull outward. Finish nails either come with the board or stay in the wall because the heads are small enough to pass through some trim types.

Side Note 2

Hide the Gaps

Take advantage of the leeway your baseboards give you in the flooring installation. The base covers the gap between the floor and the wall, which is a welcome way to conceal discrepancies in spacing.

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Side Note 3

GRIP IT & RIP IT

Grabbing carpet with pliers is a good way to get started with pulling the corners into the center of the room for carpet removal.

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