FCNews Ultimate Guide to WPC: July 17/24, 2017
While WPC-type products may be relatively new to the flooring industry, many boards can be installed using existing installation methods. Of course, installers are advised to follow the manufacturer’s recommendations for their specific product lines.
Following are some tips and installation guidelines specific to COREtec plank and tile flooring. (In 2014, COREtec Plus transitioned from a drop & lock glueless profile to an angle/tap glueless profile.) The following installation instructions refer to the angle/tap profile.
Step 1. Shuffle the deck. COREtec flooring replicates the look of a natural product which has natural variations in color, texture and sheen/gloss. For best visual effect, shuffle planks or tiles from several cartons and do not install similar planks or tiles next to one another. Be sure to inspect all flooring materials prior to installation.
Step 2. Prep the subfloor. Subfloor should be dry and level to a 3⁄16-inch per 10 feet radius for best installation results. Note: USFloors’ COREtec Plus floors may be installed with a direct glue-down method on approved wooden (or) concrete substrates that are on or above grade only. Use only USFloors Cork Underlayment Adhesive (or) comparable premium multi-purpose adhesives. Please consult with adhesive manufacturer to determine if suitable for use with this material.
While COREtec Plus is waterproof, it’s not a moisture barrier. It’s still a good idea to make sure concrete is cured and tested for moisture and that a moisture barrier is installed in the crawl space and even under a COREtec Plus floor over a concrete subfloor. Moisture won’t damage COREtec Plus, but it can get in the walls and structure of the home.
Because houses and buildings, as well as adjacent hardwood or laminate floors, expand and contract, USFloors recommends to leave a ¼-inch expansion gap between the perimeter walls and any adjacent hardwood floor. Note: Do not install COREtec Plus floors as a floating floor where it will be exposed to temperatures greater than 140°F. In areas where the floor may be exposed to direct, intense sunlight resulting in excessive heat to the floor, use the glue-down method.
Prior to installation of any flooring, the installer must ensure the jobsite and subfloor meet the requirements of these instructions. USFloors is not responsible for flooring failure resulting from unsatisfactory jobsite and/or subfloor conditions.
Flooring should be one of the last items installed in any new construction or remodel project.
Crawl spaces must be a minimum of 18 inches (46 cm) from the ground to the underside of the joists. A ground cover of 6–20 mil black polyethylene film is essential as a vapor barrier. Joints must be lapped 6 inches (15 cm) and sealed with moisture resistant tape. The crawl space should have perimeter venting equal to a minimum of 1.5% of the crawl space square footage. These vents should be properly located to foster cross ventilation.
Room temperature and humidity of installation areas should be consistent with normal, year-round living conditions for at least one week before installation of flooring. Maintaining an optimum room temperature of 70° F and a humidity range of 30-50% is recommended.
In summary, all subfloors must be dry, structurally sound, thoroughly clean and level. Wood subfloors must be dry and well secured. Nail or screw every 6 inches along joists to avoid squeaking. If not level, sand down high spots and fill low spots with a Portland-based leveling patch. Concrete subfloors must be fully cured, at least 60 days old, and 6-mil polyfilm is recommended between concrete and ground.
Ceramic tile, resilient tile and sheet vinyl must be well bonded to subfloor, in good condition, clean and level. Do not sand existing vinyl floors, as they may contain asbestos.
Step 3. Start the installation. Work from several open boxes of flooring and “dry lay” the floor before permanently laying the floor. This will allow you to select varying textures, colors and sheens, and to arrange them in a harmonious pattern. Remember, it is the installer’s responsibility to determine the expectations of what the finished floor will look like with the end user first and then to cull out pieces that do not meet those expectations.
Begin installation next to an outside wall. This is usually the straightest and best reference for establishing a straight working line. Establish this line by measuring an equal distance from the wall at both ends and snapping a chalk line. The distance you measure from the wall should be the width of a plank or tile. You may need to scribe cut the first row of planks or tiles to match the wall in order to make a straight working line if the wall is not square or “true.”
You may want to position a few rows before starting installation to confirm your layout decision and working line. Helpful hint: When laying flooring, stagger end joints from row to row by at least 8 inches (20 cm) for planks, and equal to 12 inches (51 cm or a half piece) for tiles. For plank installations, you can use the cut-off end to begin the next row when cutting the last plank in a row to fit. If the cut-off end is less than 8 inches, discard it and instead cut a new plank at a random length (at least 8 inches in length) and use it to start the next row. For tile installations, always begin a row with either a full tile or a half tile so that the joints are consistently staggered in a “brick work” type pattern. Always begin each row from the same side of the room.