Ecostrong - Installation

Prior to delivery of the flooring to the job site, the building should be closed in with outside windows and doors in place. All concrete, masonry, sheetrock and framing members, etc. should be thoroughly dry. In warm months the building must be well ventilated; during winter months heating should be maintained near occupancy levels at least five days before the flooring is delivered and until sanding and finishing are complete.

The flooring should be placed in the room where it will be installed and removed from all packaging. The flooring should be stacked so that it gets maximum exposure to the air. For example, it can be stacked in a grid pattern, with the first layer laid out with 2-3 inches of space between each plank, then stack the next layer on top of the first layer perpendicular to the first layer, also 2-3 inches apart. The flooring can be stacked in this way up to 3-4 ft high. The flooring should be stacked top-to-top and bottom-to-bottom to avoid unnecessary wear on the finish.

The sub-flooring surface must be clean, dry, and free of contaminants that would interfere with any adhesives that may be used. The sub-floor must be level and smooth prior to installation. With current constriction specifications, the National Wood Flooring Association(NWFA), in conjunction with the American Plywood Association(APA), have determined the following underlayment requirements for bamboo flooring installations based on the spacing of supports.

Some plywood is not suitably dry when installed. If the moisture content of a wood sub floor is higher than 12% when the flooring is installed

On concrete sub-floors, flooring must not be installed if the vapor pressure exceeds 3 pounds per 1000 square feet in 4 hours. The concrete should be checked for flatness and low spots should be filled to a minimum of 3/16” (4.75mm) in a 10-foot (3.05m) radius or 1/8” (3.175mm) in a 6-foot (1.83m) radius. High spots should be ground down to level. The surface must be free of all dirt, debris, oil, and solvents.

To be certain normal slab moisture does not reach the finished floor, a proper vapor retarder must be used on top of the slab. Where this is placed will depend on the type of system used. The vapor retarder should have a U.S. perm rating of less than 1 perm. 6 mil polyethylene film has a 0.04 perm rating and is considered a good choice.

With 3/4" plywood used as a nailing base, the recommended vapor retarders are affixed to the slab. These systems may be either 2 membrane asphalt felt/building paper and mastic or a 4-6 mil polyethylene film or an equivalent system as described below.

Two membrane asphalt felt or building paper system: Prime and apply cold cut-back asphalt mastic with a notched trowel at the rate of 50 sq. ft per gallon. Let set 2 hours. Roll out 15 lb. asphalt felt/building paper, lapping edges 4". Butt ends. Over
this apply a second similar coating of mastic and roll out a second layer of asphalt felt/building paper. Lay both layers of felt in the same direction, but stagger the overlaps to achieve a more even thickness.

Polyethylene method: When slabs are well above grade and the expected annual rainfall is light to moderate, cover the entire slab with 4- to 6-mil polyethylene film, overlapping edges 4-6" and allowing enough to extend under the baseboard on all sides.

Where moisture conditions are considered more severe prime and apply* cold-type cut-back asphalt mastic with a straight-edge or fine tooth trowel over the entire slab surface (100 sq. ft. per gal.). Allow to dry about 1 hour. Lay the 4-6 mil polyethylene film over the slab, covering the entire area and lapping edges 4-6". "Walk in" or roll in the film, stepping on every square inch of the floor to insure proper adhesion. Small bubbles are of no concern, and may be punctured to allow captive air to escape.

Planks shall be started square with the room and parallel to its longest dimension by positioning with a chalk line, leaving ¼” (6mm) expansion space from base plate or wall. Ensure starter rows are firmly in place by wedging or face nailing. Once initial rows are secure, second and further courses shall be blind nailed directly above tongue at a 45 to 50 degree angle to the face. Fasteners shall be spaced at 10” (250mm) to 12” (300mm) intervals, with a minimum of two fasteners per piece. Nails or cleats should not be placed closer than 6” (150mm) from the end of planks to prevent splitting.

Where moisture is prevalent, use a wood flooring adhesive spread with a ¼” by 1/8” square notched trowel. Planks should be started square with the expansion space from the base plate or wall. Ensure starter rows are firmly in place by wedging or face nailing. Once initial rows are secure, use adhesive in a Wet-Lay or Walk On Work method of installation. WET-LAY METHOD: Apply adhesive to substrate with a suitable trowel. Immediately place flooring onto “wet” adhesive. WALK ON WORK METHOD: Apply adhesive to substrate with a suitable trowel and allow it to develop tack (may take as much as an hour or more depending on temperature and humidity). Install flooring onto “tacky” adhesive. Immediately roll finished installation with a 150-lb roller. Room planks and adhesive should all be conditioned at room temperature for 48 hours before and after installation.

With radiant heat, the heat source is directly beneath the flooring, so the flooring may gain moisture or dry out faster than a similar floor in a home with a conventional heating system. Flooring can be installed over radiant heat as long as you understand radiant heat, how it can impact the flooring, and what precautions to take. The following installation systems can be used successfully over radiant heat: Glue Down; Direct Nail to Sub-floor: Tongue & Groove; Single Layer of Plywood on Sleepers; Double Plywood Floating; Floating Solid Clip; Floating Engineered/Laminated.

Installation should provide for addition of a floating underlayment system consisting of 2 layers of ½” (12mm) CDX Plywood laid at 90 degrees to each other with staggered seams and ¼” (6mm) gapping between sheets. They are attached by gluing and screwing the layers together with screws spaced at 10” (250mm) spacing to each other horizontally and vertically. The floating layer should have a ¾” (18mm) gap around the perimeter. This layer is then treated as a sub-floor and the planks may be installed as described above for nailing or gluing.

The installer should refer to the recommendations of the NWFA for specifics involving the installation of hardwood flooring over radiant heating systems. The Radiant Panel Association (www.rpa-info.com) is helpful with information and installers.