Engineered Installation

Somerset Engineered Hardwood Flooring Installation Guidelines

INSTALLER / OWNER RESPONSIBILITY - VERY IMPORTANT

INSTALLATION CONSTITUTES ACCEPTANCE of flooring material, subfloor/substrate, the jobsite itself including the ambient temperature and relative humidity at the time of installation, and all impacting variables that may affect a wood floor. It is the responsibility of both the installer and owner to inspect and approve each piece of flooring prior to installation. IF THE FLOORING AS SUPPLIED WILL NOT SATISFY THE CUSTOMER IN FULL, DO NOT PROCEED TO INSTALL. The decision not to proceed should be made within the first 10% or 100 square feet of flooring opened, whichever is less. Industry standards allow a variance from grading and manufacturing tolerances of 5%. For hold harmless agreements check with legal counsel. (refer to NWFA, Ch 1, Part 1, C.).

Many important decisions must be made at the installation site, and therefore must be the sole responsibility of the installer/owner. These include but are not limited to proper storage and handling, complete evaluation and permanent recording of site conditions including moisture testing of the sublfoor and flooring, acclimation of flooring to appropriate conditions, subfloor preparation, flooring layout, milling, grade, color and gloss, scraping, proper installation methods, sufficient quantity on hand to complete the job, and jobsite cleanup.

Site Conditions, Handling, and Storage (NWFA Installation Guidelines, Sec. I):

Somerset engineered hardwood flooring may be installed above, on, or below grade. Somerset flooring should be installed only after all work that may affect the flooring is completed. Drywall, paint, and any other “wet work” should be thoroughly cured. Moisture testing should be performed before delivery of flooring to confirm the flooring will not be adversely affected by job site conditions. When handling bundles/packages avoid damage to the finished face and milled ends/edges of the flooring.

Subfloor Types And Conditions (NWFA Installation Guidelines, Sec. II):

General:
The subfloor must be clean, dry, flat (within 3/16” in 10’), and structurally sound. Panel joints must be flush. Correct any squeaks before installation of hardwood flooring.

Wood/panel subfloors: (NWFA Installation Guidelines, Sec. II, Ch. 4).
CD Exposure 1 plywood and OSB Exposure 1 subfloor panels are appropriate subfloor materials (grade stamped US PS1-95). Solid board subfloors should be 1" x 6" nominal, Group 1 dense softwoods, #2 Common, KD. Minimum single layer panel subfloor thickness is 5/8” plywood or 23/32" OSB on 16” o.c. joists (APA Sturd-I-Floor stamped). The flooring must run perpendicular to the floor joists, or 1/2" additional subfloor thickness is required. See NWFA Installation Guidelines, Sec II, Part IV for information on other joist spacing and panel thickness requirements, engineered flooring systems, etc. Subfloor moisture content should be within 4% of finished floor m.c. for 2-1/4" flooring (Sec. II, Ch 4, Part II, A). Subfloor m.c. should be within 2% of finished floor m.c. for 3-1/4" or wider flooring (Sec. II, Ch 4, Para II, B). Wood subfloor should not exceed 12% m.c. (Sec IV, Apx C). If moisture tests indicate marginal moisture presence but the subfloor is visually dry, use Somerset 25 adhesive.

Concrete subfloors (NWFA Installation Guidelines, Sec II, Sec. IV, Apx C) Concrete should be minimum of 3000 psi.

Concrete must be tested for moisture. The two categories of testing are:

  1. Qualitative (meters, chemical); indicate potential moisture, but cannot indicate specific moisture levels. If qualitative moisture tests indicate moisture presence but the subfloor is visually dry, use Somerset 25 adhesive or perform quantitative testing as follows:

  2. Quantitative tests (if needed) include:
    Relative Humidity (ASTM F-2170)
    Calcium Chloride (ASTM F-1869)
    Calcium Carbide (ASTM, modified, D-4944-04)

Installation (NWFA Installation Guidelines, Sec. III):

Preparation
Allow expansion space (equal to flooring thickness) between the wood flooring and any walls or obstructions. Undercut door jambs, casings, etc. as needed so flooring has adequate expansion space.

Layout
Establish a primary working line, realizing the room is not square and no wall is perfectly straight. The best appearance is usually parallel to the length of the room, but always install perpendicular to the floor joists (wood subfloors) unless the subfloor meets special qualifications (see wood panel subfloors section). Always rack out the entire job before installing to avoid clustered joints or patterns, and to achieve a good color blend.

Installation with Mechanical Fasteners (Cleats/Staples):

Over the subfloor, install a layer of #15 building felt (or equivalent perm rating), overlapped 4” at the seams. See NWFA, Sec. III, Ch. 8, Part 4 for more detail on acceptable moisture barriers. Use caution to avoid edge and face damage during installation. Special footer plates are available for flooring nailers to protect factory finished flooring from nailer damage. Use a tapping block as required.

Fasten a backer board of minimum 1/2” plywood ripped to an appropriate width to establish straight working lines. Backer boards should be secured to the subfloor and carefully aligned with the primary line.

Use flooring fasteners (NWFA Installation Guidelines, Sec. IV, Appendix F) designed for engineered flooring (staples - minimum 1” long, maximum 3/8 crown, or cleats - 1" to 1 1/4"). Air pressure and tool settings should be adjusted so the fastener seats properly in the nail pocket, does not split the wood, and does not distort ("dimple") the face. Fastening schedule should be every 3-4” (staples) or 4-6" (cleats), with a fastener 1-2” from each end, minimum two fasteners per piece. DO NOT USE TOOLS OR FASTENERS DESIGNED FOR 3/4" SOLID FLOORING.

Face nail only as required with 1” (4d) finish nails or cleats, 1/2” from the groove, pre-drilling the nail holes to prevent splitting. Face nails should be countersunk and filled.

Adhesive Installation:
We recommend Somerset 25, Somerset 47, or Somerset 50 adhesive. Other adhesive brands may be used, but choosing another product will defer all adhesive related issues to the adhesive manufacturer. Refer to the adhesive container label regarding adhesive storage, proper ventilation, trowel notch size/pattern, spread rate, open time, safety procedures and equipment, cleanup and cure time. Spread adhesive to accommodate working from one side of the installation, chalking lines to guide over/under spreading adhesive (example; if installing 5" flooring, spread a 25" wide row). Work off the floor to avoid shifting the flooring in the adhesive. Avoid allowing adhesive residue to contact the face of the flooring. Odorless mineral spirits will clean Somerset adhesives from the finish; immediate cleaning is recommended for Somerset 25 and Somerset 50 urethane formulas; Somerset 47 allows longer lag time in removing adhesive residue.

Floating Installation (1/2" Thick Products Only):
Somerset engineered flooring may be floated over a structurally sound subfloor, using a quality tongue & groove glue (must remain elastic when cured) applied in a continuous bead along the bottom of the grooves (both edge and end groove). A quality floating floor underlayment pad should be installed between the subfloor and the flooring installation. Other installation guidelines remain unchanged.

Finishing Touches:
Somerset offers five standard molding profiles factory finished to blend with your Somerset wood floor. These moldings will address most trim and transition situations quickly and cost effectively. Moldings should be ordered and delivered with the flooring so they can be cut and placed before the flooring, then flooring can be chosen to best blend with the specific piece of molding.

Fill any nail holes or small cracks with an appropriate colored filler. Somerset Touch-Up Kits are available; leave the Touch Up Kit with your customer for their use as needed.

Remove all debris and clean the floor thoroughly using Somerset Ultimate Cleaner. A Somerset floor care kit makes a good closing gesture, and encourages proper maintenance. Additional information is available at www.somersetfloors.com.

Applying additional finish over the factory finish does not improve durability or permanently seal the joints, may cause problems, and will void your limited warranty.

If you have installation questions, contact Somerset, your Somerset distributor, or the National Wood Flooring Association (www.nwfa.org).

Somerset Hardwood Flooring
P.O. Box 1355
Somerset, Kentucky 42502

NO WARRANTIES APPLY TO ANY PRODUCTS NOT SPECIFICALLY ADDRESSED IN Somerset's WRITTEN WARRANTY DOCUMENT.

THE FULL LIMITED WARRANTY DOCUMENT IS AVAILABLE AT somersetfloors.com/pages/warranty.html

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