Installation Guidelines for Velvet
The importance of understanding the construction of the product is as important as the installation itself. Understanding how to manipulate the product when needed to have it conform to its surroundings is essential.
Acclimation is a very important step in achieving this goal. Carpet should be cut and laid in the area it is to be installed, for a minimum of 24 to 48 hours before installation. Always add 3 inches to each cut, and when patterns are involved 3 inches plus a full pattern should be added.
The velvet is the simplest form of a weaving loom. There is however a wide variety of texture and color effects that can be produced with either loop or cut pile of varying heights. The loop pile is designated as round wire Velvet. A cut pile is simply a cut pile Velvet.
Velvet carpet yarns all appear on the face of the carpet. That means all the yarn is used to form the pile. Bulk is obtained by the warp, and stiffer yarns.
Velvets are known in the commercial market as quality carpet as they can be produced in good quality, with excellent tuft bind and density, in a economical manner. As the backing is woven in a tremendous variety of qualities, in small quantities, designed directly for the end use area.
A typical high quality Velvet may have 8 to 10 wires per inch and a pitch of 216 per 27 inch width.
Variations in the grades of Velvet depend on the number of weft or shot yarns used per row of tufts to bind the yarn in place. The most common is a two shot construction: that is, each row of tufts is held by two shots of the weft yarn. Velvet carpeting may be multi-colored or solid.
1.Velvet carpet can be stretched in both directions. Unlike Axminster, Velvets don’t stretch as much in the length as the width. The tack strip to be used for Velvet carpet is architectural strip with 3 rows of pins or “Tri Tack” with 3 rows of pins.
1.2 Tack strip must be a minimum of one inch (25mm) wide and 1/4 inch (6mm) thick. Architectural strip with 3 rows of pins, or two conventional strips with two rows of pins each, must be used for carpet with heavily-latexed backs, for most woven and Berber-style carpet, and for any carpet in rooms exceeding 30 feet (9m) in length or width. To prevent possible injury to building occupants, the pins on tack strip must not protrude through carpet being installed. To avoid pins showing through, you can cut the selvage off the side of the carpet and lay it across the tack strip to lower the pins.
2. A firm pad should be used, preferably wool pad, 32 oz. felt, rubber or Healthier Choice (frothed polyurethane foam, Greenguard) note: A soft pad will create looseness and give no support to the carpet. It is not recommended to use masking tape, due to the paper drying out over time, it is also not recommended to use duct tape because over time it will cause an unevenness from the pad wearing out on each side of the tape. ( note: this is the reason it is recommended to use duct tape on stair nosing, to keep the pad from wearing in this high traffic area.) Pad should be glued at seams, not taped or stapled.
2.1 To seam Velvet there are 3 methods to use: hand sewing, Kool Glide iron or hot melt iron with premium seam tape. All methods require sealing with latex. Seam sealing is mandatory !
2.2 Prior to seaming, both trimmed edges of the carpet sections to be joined must be sealed with an appropriate seam sealer. Latex seam sealer.
2.3 Note: Cotton head should never be used on loop pile wool carpeting. Reason: When using a cotton head the yarn will swell, leaving the carpet unrepairable. If you trim the carpet, it will leave dark areas.
Direct Glue Installation:
3. Direct glue – the minimum trowel notch for direct gluing of a Velvet carpet is 1/8″x1/8″x1/8″ U notch trowel. Prior to installation some of the following conditions should be considered; Carpet must be installed when the indoor temperature is between 65-95 degrees F (18-35 degrees C) with a maximum relative humidity of 65%. If ambient temperatures are outside these perimeters, the installation must not begin until the HVAC system is operational and these conditions are maintained for at least 48 hours before, during and 72 hours after completion.
3.1 Before making an adhesive adhered installation, the owner or GC, or their designated testing agent, must submit to the flooring contractor a written report on the vapor emission level and the surface alkalinity of the concrete subflooring.
4. Moisture – Concrete floors, even with adequate curing time, can present an unacceptable moisture condition by allowing excessive amounts of moisture vapor to pass through to the surface. This can be a problem even on suspended concrete floors. Test all concrete floors for moisture emission rates using an anhydrous calcium chloride moisture test kit. This quantitative test method must be conducted carefully in strict compliance with ASTM Test Method F 1869. Moisture emission rate is measured in pounds of moisture over a 1000 sq. ft. area during a 24 hours period. Because calcium chloride testing requires a minimum of 60 hours to conduct, proper installation planning is required. As a general guideline, an emission rate of 3.0 lbs (1.4kg) or less is acceptable unless otherwise specified by the carpet manufacture.
5. Alkalinity – A pH range of 7-9 is satisfactory for alkalinity; however, a reading above 9 requires corrective measures. Perform testing in accordance with ASTM Standard Practice F-710; or consult the adhesive manufacture for recommended testing and corrective procedures.
6. Adhesive installations – The proper type adhesive/glue to use is a high solids glue. Preferably 65-68% solids .Preferably Apac 440 or any premium high solids glue.
The owner or GC must have concrete subfloors tested to determine the moisture emission rate and surface pH prior to installation. Caution: Any concrete floor, even when adequately cured and dry, can allow moisture vapor to pass through to its surface. Depending upon the type of carpet and method of installation, the moisture emission rate greatly influences the long term success of an installation. The use of a properly installed, uncompromised, approved moisture membrane is essential in preventing moisture migration into and through a concrete slab. ( Ref. ASTM F 10)
7. Relaxing/Conditioning Carpet – To minimize wrinkling and buckling, and to facilitate the installation, it is highly recommended that the carpet be unrolled and allowed to relax in the installation area for a minimum of 24 hours at a temperature between 65-95 degrees F (18-35 degrees C). Carpet must be adequately protected from soil, dust, moisture and other contaminants. To facilitate relaxation, pre-cutting carpet is recommended.
8. Ventilation – During installation, maintain fresh air ventilation using exhaust fans, and by operating the ventilation system at full capacity. Always exhaust air to the outside and avoid re-circulation. After installation, maintain fresh air ventilation for 48-72 hours at normal room temperature by operating the ventilation or exhaust fan system at full capacity. Open doors and windows, if possible. These procedures help exhaust, dissipate and eliminate lingering orders from the installation.
9. Primers – Using primers on floor surfaces generally is not required except for sanded wood sheet products, dusty, porous or acoustical concrete surfaces. Priming cannot overcome moisture vapor emissions and must not be used for that purpose. They must be compatible with adhesives, which should be applied only after the primer is cured. Where lightweight or acoustical concrete subfloor is present, refer to manufacturers recommendations for the proper installation procedure to use before the carpet is installed.
10. Liquid adhesive removers – There are a number of liquid adhesive removers available that effectively remove existing adhesive residue from sub-floors; however, there is evidence that some products may adversely affect the new adhesive or the new floor covering. Residues left in or on the concrete slab may cause failure of the new floor adhesive.
11. Sweeping compounds – These compounds may leave residue that interferes with adhesive bonding. They must not be used prior to adhesive application. Vacuum dusty areas instead.
12. Carpet layout – Layout the carpet according to the seaming diagram. Carpet must be cut 3-4 inches longer than the area measurement. Where applicable, allow for pattern repeat. Align all carpet breadths to their proper position and trim seams.
13. Adhesive application – The floor adhesive must be spread uniformly over the subfloor with an appropriate trowel, leaving ridges of sufficient height to achieve full and complete coverage of the substrate and carpet backing, including penetration into the backing’s deepest recesses. Trowel notches wear down during use. Maintain a clean and properly notched trowel throughout the installation process. After sufficient open time, the carpet must be pressed into the adhesive and rolled with an appropriate roller as specified. Caution: Bond failure most often is caused by: inadequate adhesive application from incorrect trowel notch size and/or trowel notch configuration * improper adhesive selection or quality * incorrect open time * residual curing and parting compounds * moisture-related problem * premature traffic or cleaning before adhesives have adequately cured.
14. Open time – Appropriate open time varies depending upon environmental conditions, subfloor porosity, backing system and adhesive type. Refer to the adhesive manufacturer for recommendations regarding open time.
15. Seam adhesive (sealer) – An appropriate direct-glue seam adhesive must be applied to the edges trimmed for seaming and cover the thickness of both the primary and secondary backing without contaminating face yarns. The seam adhesive is applied to the cut edge of one side only, that side being the first one placed into the floor adhesive. When the edges are abutted to form the seam, and while the seam adhesive still is transferable, this seals the first edge as well as the second.
16. Rolling – After sufficient adhesive application and open time, the carpet must be pressed into the adhesive and rolled with an appropriate roller. Rolling must be performed with the lightest roller that achieves full and complete coverage of the substrate and carpet backing, including penetration into the backing’s deepest recesses.
17. All seams should be sealed with appropriate seam sealer. The roller to be used for direct glue should be no more than and no less than 75 lbs.
Double Glue Installation:
18. Relaxing/Condition carpet – Site conditions, environmental and ventilation conditions become even more important when performing double-glue-down installations. In double-glue installations, a separate cushion is adhered to the subfloor and the carpet is glued to the cushion.
19. Cushion installation – Cushion must be installed in the longest continuous lengths possible with consideration to traffic patterns and carpet seam placement. Cushion seams must be at a right angle (90 degrees) to carpet seams or offset at least six inches. Cushion seams must be butted without compression, leaving no gaps.
19.1 Make sure that the glue has time to off gas and set up. Tacky to the touch, but not transferred to the finger.
19.2 The recommended pad to be used for double stick installation is a 21lb. rubber slab pad or Healthier Choice pad – felt pads or wool pads are NOT recommended for this type of installation.
20. Carpet layout – Layout the carpet according to the seaming diagram. Carpet must be cut 3-4 inches longer than the area measurement. Where applicable, allow for pattern repeat. Align all carpet breadths to their proper position and trim seams. Care must be taken to avoid cutting into cushion under seams.
21. Trowel size for double glue installation, is as follows: Pad to floor using pressure sensitive glue is 1/16”x1/16”x1/16” square notch trowel. Carpet to pad with a smooth back carpet use a 1/8”x1/16”x1/8” U notch trowel. The proper type adhesive/glue to use is a high solids glue. Preferably 65-68% solids .Preferably Apac 440 or any premium high solids glue.
Note: Pressure sensitive glue should always be used on double stick installation, pad to floor. If multi-purpose glue is used this could cut the life span of the installation in half. Also if pressure sensitive glue is not given the time to off gas, it will do it on its own once the job is completed. The proper way to know when the time is right to put the pad into the glue, is when the glue is tacky to the touch, but does not transfer to your finger. Do not use fans directly on the glue to speed up drying time, as it will prematurely set the glue. Fans can be used facing the ceiling to circulate the air, but not directly on the floor.
22. The proper roller recommended for a double glue installation is a 35-50 lb. roller. Velvet carpet should be rolled in both directions. After 2-3 hours, the carpet should be rolled again.
On a double glue installation, it is recommended that you use a seaming iron, rather than not. If you are using the Kool Glide iron, make sure you cut the flange off of each side of the tape before using it.
23. Roll sequence – Sequence carpet cuts working from the longest measured repeat gradually down the shortest repeat within the dye lot. Roll sequencing information is available from the carpet manufacturer.
24. Pattern adjustment – Pattern adjustment during installation is possible and should be anticipated.
25. Pattern alignment – Match the pattern at the midpoint of the seams length. Work from the seam’s midpoint to the seam ends. Bring the pattern into register using appropriate tools that might include: power stretcher * knee kicker * dead man * “dry” line * stay nails * crab stretcher.
26. Curing adhesives – It is highly recommended that traffic over field-applied adhesive installations be restricted for a minimum of 24-48 hours to allow adhesives to cure properly. Premature trafficking can cause installation failure. Restrict carpet exposure to water from cleaning or other sources for a minimum of 30 days.
27. Materials for protection – If required to protect the finished floor covering from soil or paint, or if additional work is to be done after the installation, cover it with a non-staining building material paper. Protect the installation from rolling traffic by using sheets of hardboard or plywood in potentially affected area. Caution: Do not place plastic sheeting over any carpet installation because it may present a slip hazard and may leave residues that result in rapid soiling after removal. In addition, it may trap moisture, which may promote mold growth, and retard adhesive curing.
28. Maintain temperature – Do not allow the temperature of indoor carpeted areas to fall below 50 degrees F (10 degrees C), regardless of the age of installation.
** If you have any questions, please call NFIC at 770 720-4537 **