CARPET AND CARPET CUSHION

GUIDELINES FOR INSTALLATION

The carpet, carpet cushion and adhesive shall be conditioned on-site at a minimum temperature of 65oF (18oC) and a relative humidity between 10% and 65% for at least 48 hours before installation. The carpet should be unrolled to allow it to relax and be ventilated. The subfloor surface shall be prepared to make it suitable for carpet. Make the necessary moisture and alkalinity testing. The moisture emission from a concrete slab shall not exceed 3.5 pounds per 1000 square feet in 24 hours and the alkalinity test should not exceed pH 9. Thermal insulation is recommended in the floor. Installing STEP US2 under the entire floor will provide a good insulation / vapor barrier membrane. See Concrete Slab. Installation of the Heating Elements Secure the STEP WARMFLOOR heating elements directly onto the prepared substrate or onto STEP US2 Membrane. Make the electrical connections and have a certified electrician measure and check the elements before installing the floor leveler, carpet and/or STEP Heat Transmission Cushion. See Installation Procedure and Electrical Installation. STEP WARMFLOOR heating elements should be covered by leveling compound or backerboards to even the surface, especially in traffic areas, to avoid telegraphing of the elements and connectors. Where STEP Heat Transmission Cushion is used without floor leveler, STEP Terminal Boards are mandatory. Rebond or bonded urethane shall not be used over the heating elements, as this will impede heat transfer. Most carpet and adhesives manufacturers recommend that radiant heated floors should not exceed 85oF (29oC). To allow proper adhesion of the patching compounds and adhesives, the heating system should not be turned on until 72 hours after installation is completed. STEP WARMFLOOR is a passive (low radiant), self-regulating heating element that keeps an average temperature of 75oF (24oC) at 24 volts.

Installation of the Carpet and Carpet Cushion

A scale drawing of the area to be carpeted is required to determine, quantity of carpet needed, dye lot changes, proper location of seams, edge treatments, and carpet pile direction. Carpet styles, patterns, colors and installation methods should be included in the shop drawings and layout. Adhesive selection is very important and must be compatible with the carpet backing and substrate. The adhesive on the pre-glued STEP WARMFLOOR heating elements is a water based vinyl acrylic copolymer emulsion. - Glue-down Installation In direct glue-down installations, the carpet is adhered directly to the subfloor. A 100% transfer of floor adhesive into the carpet backing, while maintaining full coverage of the floor, must be attained. In double glue-down, a separate cushion is adhered to the floor, and the carpet is glued to the cushion. The cushion should be installed in the longest continuous lengths possible with consideration to the traffic pattern and seam placement of the carpet. Carpet seams should be at a right angle to cushion seams or off set at least 6 inches (150 mm) to either side. Glue scrim side of pad 100% to the floor. Cushion seams must be butted without compression, leaving no gaps. After the cushion has been secured, the adhesive shall be spread uniformly over the cushion surface with the specified trowel. It is important that the trowel notch be large enough to apply a continuous film of adhesive for 100% transfer into the backing while maintaining full coverage of the cushion surface. After sufficient open time, the carpet is to be pressed into the adhesive and rolled with the appropriate roller.

Stretch-in Installation This method requires fastening the carpet under tension onto tackless strip around the perimeter of the area to be carpeted. When affixing the tackless strip, take care not to nail through the bus braids running along each side of the heating elements. Cut the tackless strips and leave a gully on the floor where the wires are routed to the electrical box on the wall. A separate cushion shall be used. Improper cushion selection for the end use application of the carpet may result in accelerated loss of appearance retention, wrinkling, buckling, and the separation of the carpet backing or seams. Cushion is to be installed in the longest continuous lengths possible. Cushion seams should be placed at right angles to the carpet seams at least 6 inches (150 mm) to one side of the carpet seams. Cushion shall be securely fastened to the subfloor with staples or cushion adhesive at the seams and around the perimeter of the installation. Cushion seams shall be secured with duct tape or equivalent. Cut the carpet and carefully trim the edges that are to be joined as seams. An appropriate seam adhesive must be applied to both trimmed edges. Pre-stretch the carpet in the seam direction before making the seam. Carpet must be power stretched and firmly hooked onto the tackless strip at the starting walls and on the tackless strips in the surrounding area. Tautness of the carpet is essential to assure a good, long lasting installation.