A floor patch

Marked boards for repair around the gouge.
To repair: to restore to a good condition. To patch: to restore in haste in a makeshift way. Educated and responsible wood flooring contractors repair floors with damaged or defective pieces; they don't patch a floor.

A corollary to NOFMA's Standard of Inspection for Wood Flooring: When viewed from a standing position, a repair should not be noticeable. It should be consistent with the rest of the flooring and have a uniform appearance.

Repair is critical to completing many jobs. The customer may have asked that an objectionable board be removed. Damage may have occurred from another source that needs repair before the invoice can be sent. Many other scenarios can pop up but the ultimate objective is to restore the floor and have the customer not be able to notice the restored area. At the NOFMA/ MFMA/NWFA Flooring School instructors demonstrate a single board repair on unfinished flooring as well as an area repair on previously stained solid wood flooring. During practice time, student participants gain hands-on experience doing the repair. For those who have not attended a Flooring School, we'll review the process here.

How to repair a site-finished wood floor

If the finishing has not yet begun, the repair is simplified. These repairs are normally associated with defective boards such as splits, bit ends, shake, deep gouges, etc.

Breaking the ends of the saw kerfs and chiseled center cut.
The board is removed then finishing can proceed.

Power tools needed: circular saw, miter saw, and vacuum. Hand tools needed: claw hammer, sharp 3/4-inch and 1/2-inch wood chisels, utility knife, nail puller (end nippers), nail set, pencil, block plane, flooring nailer and fasteners, epoxy glue and applicator. Safety equipment: ear plugs and safety glasses.

The procedure is to plainly mark the boards to be replaced. You don't want to turn a single board repair into an area repair. Set the circular saw depth of cut to the exact thickness of the flooring. Make two parallel cuts the length of the board 1/2-inch or so from the long edges and cross cut the center on an angle (take care not to cut into adjacent boards that do not need repair). Break the kerfs at the ends with the chisel and chisel through the cross cut.

Chiseled out tongue piece and removing nails and felt.
Remove the center piece and the groove edge piece. The tongue edge will have to be chiseled out and the remaining nails pulled. Cut the felt paper out of the exposed area and vacuum clean.

Next select a replacement board that is similar to the surrounding flooring in color and grain pattern. Be sure it is the same species and near the moisture content of the existing flooring. Fit the piece in the open space on edge and mark with a utility knife for exact length. Cut to length on the miter saw. Cut off the bottom lip of the groove edge and groove end. Block plane the lower edge of the top groove lip on a slight angle. Trial fit into place, using the plane to better fit until the board almost fits home. The trail fit is very important for a snug fit with no gaps and to be able to tap the board home without damaging the surrounding boards. Apply the epoxy glue to the existing exposed tongue and into the groove of the opening in the flooring.

Clean the opening.
A glue squiggle across the exposed subfloor adds insurance. Roll the tongue edge into the groove and tap the groove edge home with a scrap piece of flooring.

An area repair is similar but with multiple boards. With an area, you can usually blind nail some of the replacements and glue the last board. For a larger area, make a "story board" of the existing floor spacing using a straight piece of flooring by marking at each board intersections edge. Use this story board to position or locate each of the replacement boards so that the space for the last fitting board is not too narrow nor too wide. Now comes the hard part. If the flooring has a finish and or stain, contractor experience becomes critical in the repair. Again, the objective is to make the repair blend with the surrounding flooring and not be noticed.

Replacement boards cut and 'dry fitted.'
The flooring has to be sanded the same as the other areas; the stain has to be the same color; and the final finish must be a continuous film without an identifiable edge. The experienced contractor will make decisions on proper grits for sanding, color for staining, and the final coating.

The following will illustrate the procedures for repair. These steps are not all-inclusive but will give the "flavor" for what is necessary.

Nail where possible.
A slightly different sequence or technique may be necessary to accomplish the same end depending on the circumstances with which you are faced.

The basic tools and items needed: a good set of eyes and hands, edger with proper grit paper (80, 100, 120), vacuum, broom, steel straight edge, sharp flooring scraper 3/4-inch to 11/2 inches wide, different grits of hand rub sanding paper (100, 120, 150, 180, 220), finishing materials (stain, finish, solvent, rags, brushes), safety equipment (respirator, ear plugs, gloves).

Apply epoxy to tongue and opposite groove.
Begin by sanding the replacement flooring with the edger. Use the last sanding grit applied to the floor, such as 100 paper where a 100 screen was used. Sand from center area to edge, and check often with the hand and straight edge to check flatness with the existing flooring. Sand lightly into the existing flooring to blend the perimeter. Do not sand too deep; the repair WILL show. The area sanded should be flat with the existing flooring.

Tapping last board in place.
Use the scraper to smooth the repair. Scrape with the grain. Also scrape into the existing flooring perimeter a little further than the sanded area and along every other grain line. This blends the repaired area with the existing floor more uniformly. Hand sand the area scapped and into the surrounding existing flooring with the same 100 grit paper.

Edge boards flat with 100 grit, the last grit used on the flooring.
Sand with the grain along the length of boards with the same 100 paper. This mimics the drum sander scratch. Hand sand with 180 paper, then 220 paper. Use an even flat pressure, don't gouge with the finger tips. Feel the area often and re-sand uneven areas.

Apply color matched stain in the center of the sanded area and wipe from edge to center.

Scrape with the grain to flatten and straighten edger scratches.
If top coats have already been applied to the flooring, wipe the stain off the finished edge with solvent.

Previously sanding the finished edge with 800 or so automotive paper will slick the edge of the finish so stain can be completely wiped off and not create a halo. After the stain is dry degloss the finish around the perimeter and apply finish over the repaired area.

Hand sand with 180 grit after hand sanding with 100. Note that every other grain line has been scraped into existing finish.
After drying degloss and apply a second coat if necessary. Most of the time, the final step is to degloss and coat the entire floor for a uniform appearance and color.

Apply stain; start in the center.
Practice and learning from experiences can make the repairs successful. Don't rush the job; it may even take a week or two to complete the repair.

Rub off excess stain; work from edge to center.
Don't promise what you can't deliver. With a high-end job and extensive furnishings, an area repair can be more efficient and consumer friendly than refinishing the entire floor.

Voila! A Finished repair.
To see the repair first hand, come to the NOFMA/MFMA/NWFA Flooring School. The next one is September 18 thru 22, 2004; for information and application, visit www.nofma.org.