A. Always follow the manufacturers recommended installation procedure.

B. Unfinished and factory-finished solid plank should be installed perpendicular to the joists or on a diagonal for any single layer subfloor. (Exception: Over diagonal, solid subfloor boards, install perpendicular to joists or subfloor direction.)

C. When ¾" solid plank flooring is laid parallel with the floor joists, follow one of these two steps:

  1. Add a layer of minimum nominal ½" (15/32”) CD Exposure 1 (CDX) plywood underlayment to the existing subfloor (as previously recommended)

  2. Or brace between truss/joists in accordance with the truss/joist manufacturer’s recommendations and with local building codes. Some truss/joist systems cannot be cross-braced and still maintain stability.

D. Before installing wood flooring, place an approved vapor retarder. Some examples of acceptable vapor retarders over wood subfloors include:

  1. An asphalt laminated paper meeting UU-B-790a, Grade B, Type I, Style 1a.

  2. Asphalt-saturated kraft paper or #15 or #30 felt that meets ASTM Standard D-4869 or UU-B-790, Grade D.

E. Wall Line Layout

  1. Choose a starting wall according to the most aesthetically or  architecturally important elements in the room, taking into consideration fireplaces, doors, cabinets and transitions, as well as the squareness of the room. The starting wall will often be the longest unbroken wall in the room.

  2. Snap a working line parallel to the starting wall, allowing ¾” expansion space between the starting wall and the edge of the first strip or plank run.

  3. As a general rule, a ¾” expansion space must be left around the perimeter and at all vertical obstructions.

  4. Random-width plank is laid out with alternating courses varying by widths. Start with the widest board, then the next width, etc., and repeat the pattern.

  5. Lay one row of strip or plank along the entire length of the working line.

  6. Top-nail and blind-nail the first row (hand-nail if necessary), using appropriate fasteners. Denser species may require pre-drilling. Each succeeding row should be blind-nailed with the nailing machine wherever possible. At the finishing wall and other obstructions, it may be necessary to blind-nail by hand until top nailing is required.

  7. Racking rule of thumb: Stagger end-joints in adjacent rows at least three times the width of the boards, as product allows. Avoid H-joints. (See Figures 1 and 2.)

Figure 1 Stagger End Joints		Figure 2 Avoid “H” Joints

9. Where spacing is required: Use a washer or removable spacer to leave additional space

every few rows and/or start in center of room and work out to both sides. Do not use

spacers that may cause damage on factory-finished products.

10. Nailing: Blind-nail through the tongue using 1½"-2” fasteners. Use 1½" fasteners with

nominal ¾" plywood subfloor direct to concrete slab. Face-nail boards where needed

using 6d-8d casing or finish nails. Fasteners should be spaced every 6”-8” on blindnailing,

or every 10”-12” on face-nailing.

11. For additional fastening, any of the following options may be used in addition to the

nailing schedule. (See Appendix F, Fastener Schedule.)

12. Follow manufacturer’s instructions for installing plank flooring.

13. For wide-width plank flooring (5” or wider), to assist the nailing schedule of 6”-8” and

increase holding power, there are three options.

a. Screw and plug at end joints, alternating at staggered locations and intervals along

each board.

b. Apply an approved wood flooring adhesive.

c. Use kerfing or relief cuts every 8” to 12” parallel to the grain – using more relief cuts

for wider boards. Typically, the relief cut should be 3/8” on a ¾” board.

14. Blind-nail and face-nail, as necessary, to complete the final rows.

F. Center Line Layout

1. Find the center of your room, measuring off the two longest walls, and snap a line down

the center of that room.

Copyright 2007 National Wood Flooring Association 13 Revised March 2007

Chapter 9 Solid Strip & Plank Flooring Installation

2. Install a starter board on the line. Fasten the starter board to the floor using wood

screws.

3. Nail the first row of wood flooring against the starter board, being careful not to move the

starter board when nailing. The groove of the flooring should be against the starter

board.

4. Drill and hand-nail the first three rows through the tongue. DO NOT USE TOP NAILS.

5. Use a blind nailer to install the remaining rows of wood flooring. Use the nailing practices

described earlier in the chapter.

6. After installing in one direction, remove the starter board and start rows going in the

opposite direction.

7. Install a spline or a slip tongue in the groove of the board that was against the straightedge.

Put wood glue down the entire length of the groove before installing the spline.

8. Install the spline using a blind nailer. To keep the spline in alignment for the next flooring

board, use a scrap piece of wood flooring to run along the length of the spline as you

nail.

9. Install the remaining rows in the opposite direction. Use the nailing practices described

earlier in the chapter.

A. Engineered wood flooring can be installed directly to screeds, provided the engineered flooring is a minimum of ¾” thick. For engineered flooring less than ¾” thick, the screed system must be overlaid with proper subflooring. See Appendix I, Installation Over Screeds.

B. Note on random-width plank

  1. Random-width plank is laid out with alternating courses varying by widths. Start with the widest board, then the next width, etc., and repeat the pattern.

  1. Choose a starting wall according to the most aesthetically or architecturally important elements in the room, taking into consideration fireplaces, doors, cabinets and transitions, as well as the squareness of the room. The starting wall will often be the longest unbroken wall in the room.

D. Glue-Down Engineered Strip and Plank

  1. There are several different ways to start the installation of glue-down engineered wood flooring. The following has proven successful. However, where instructions differ from manufacturer recommendations, manufacturer recommendations prevail.

  2. Test the substrate for moisture according to appropriate moisture testing procedures in the General Guidelines. Excessive/elevated moisture should not be present. The subfloor should be within acceptable moisture content as per adhesive and wood manufacturer’s recommendation before installing.

  3. Expansion space should be left around the perimeter in accordance with the manufacturer’s recommendation.

  4. Snap a working line parallel to the starting wall, the width of the board, plus the tongue and recommended expansion space.

  5. Install a starter board along the edge of the working line and begin installation. Alternatively, lay one row of plank in the adhesive along the length of the working line.

  6. Follow manufacturer instruction for tongue and groove direction and placement.

  7. Use an adhesive approved by the flooring manufacturer. Follow the installation procedure recommended by the adhesive manufacturer, which includes subfloor moisture content, spread rate, trowel size, open time, working time and flash time as necessary. Spread the adhesive as instructed up to and along the working line

  8. Distribute lengths, avoiding “H” patterns and other discernible patterns in adjacent runs. Stagger end joints at least three times the width of the boards, as product allows. (See Figures 1 and 2.)

Figure 1 Stagger End Joints		Figure 2 Avoid “H” Joints

  9. If recommended by the manufacturer, use tape or tensioners to maintain a tight floor.

  10. If recommended by the adhesive manufacturer, roll the floor with the proper roller.

E. Mechanically Fastened Strip and Plank

  1. If necessary, add a vapor retarder.

  2. Snap a working line parallel to the starting wall, allowing expansion space as specified by the manufacturer.

  3. Lay one row of plank along the entire length of the working line.

  4. Top-nail and blind-nail the first row (hand-nail if necessary), using appropriate fasteners. Denser species may require pre-drilling. Each succeeding row should be blind-nailed wherever possible.

    b. Typical: every 3-4” with staples, every 4-6” with cleats, and within 1-2” of end joints. Use appropriate size fastener for top nailing first row, last row and any area where blind nailer will not fit.

  5. Add each additional row of flooring. Distribute lengths, avoiding “H” patterns and other discernible patterns in adjacent runs. Stagger end joints at least three times the width of the boards, as product allows.

  6. During installation of flooring pieces, push or gently tap boards flush to the previous row. Tap against the tongue; tapping the groove may damage the edge. To prevent damage to the finish, avoid tapping the face of the board with a rubber mallet.

F. Floating Engineered Flooring

  1. Subfloor flatness is critical to the success of a floating floor installation. (See Chapter 4, Wood Subfloor Guidelines, and Chapter 5, Concrete Subfloor Guidelines.)

  2. Test the substrate for moisture according to appropriate moisture testing procedures in Chapter 3. Excessive/elevated moisture should not be present. The subfloor should be within acceptable moisture content as per manufacturer recommendation before installing.

  4. If necessary, add vapor retarder. (See Acceptable Vapor Retarders in Chapter 3, Moisture Requirements and Moisture Testing.)

  5. Expansion space should be left around the perimeter or in accordance with manufacturer’s recommendation.

  6. Typical: Subfloors are covered with a resilient material, foam underlayment or cork. Follow manufacturer's instructions for correct materials and thickness.

  7. Typical: floating engineered flooring is edge-glued or edge-attached with a self-locking mechanism.

    a. For edge-glued products, use an adhesive approved by the manufacturer.

    b. Apply adhesive at the spread rate to the side grooves and/or ends as recommended by the manufacturer.

  8. Starter boards should be aligned with the groove side and end against the starting wall. Tapping block should be used against tongue only.

  9. Stagger end joints per manufacturer’s recommendation. Typical: 18”-20”.