Installation Guidelines for Wilton

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.

Wilton is one of the three major woven carpets. Wilton is processed on a Jacquard loom which has a special mechanism to form patterns in the surface pile and at the same time implant some of the pile yarn on the back. That means all the yarn used does not appear on the face pile. The Wilton loom utilizes frames from which spools of yarn are drawn into the loom to form the pile. If a five frame carpet is desired, yarns of five different colors could be fed into the loom. This flexibility of the loom is so extensive that literally dozens of colors are possible to weave in a single operation.

An interesting feature of the Jacquard system for Wilton is a punch card system, ( similar to a computer card ) for selecting the pile yarn for the carpet face. The cards are laced together and suspended in the loom exactly as the pattern is to appear on the carpet face. The card determines which color yarns are to be lifted to the face and which are to be buried in the carpet body. There may be several strands of yarn beneath the face for every one showing, depending on the number of frames of color used. The loom can be adjusted to allow the “planted” yarns to show through to the surface for special effects.

The addition of each frame or color to a Wilton will add more yarn to the carpet pile. A five frame Wilton will have more weight than a three frame Wilton of the same yarn size and density. The performance capability of a Wilton depends in great measure on the pile yarn weight, its height and yarn count.

The pile density is controlled by the pitch ( number of warp lines of yarn in a 27 inch width) by wires per inch ( number of weft shots per inch, and by yarn count, weight thickness of a single strand of fiber ) and pile or wire height. A high quality Wilton may be made with 252 pitch and 8 to 10 wires per inch, with a lighter or heavier yarn to provide density.

Other combinations of weight, density and pile height provide different carpet with varying performance capabilities. A dense low pile, of a given weight and construction, though not feel as comfortable under foot.

The loom will also weave Wilton’s with sharply delineated sculptured and embossed textures. The pattern effect is achieved by varying the pile height, by using different wire heights, by using a combination of cut and uncut pile, and by using a combination of different yarns.

Stretch-in Installation:

1.Wilton carpet can be stretched in both directions.  Tack strip to be used for Wilton 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 heavly-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 becuase 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 Wilton 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 ! Seam preparation is more critical than anything you can do with a Wilton, and is taught in NFIC training course.

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.

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  Wilton 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.  Seam preparation is more critical than anything you can do with a Wilton, and is taught in NFIC training course.

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 and 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. Carpet to pad with a rough back carpet use a 1/8”x3/16”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. Wilton 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.

Understanding Carpet Manufacturing Tolerances on Pattern Carpet:

23. A successful patterned carpet installation requires a thorough understanding of patterned carpet characteristics by designers, specifiers, and all others involved with the carpet selection and installation. Carpet is a textile fabric subject to inevitable process variations, which are more critical when patterns are involved. Most manufacturers provide established tolerances and specific installation instructions for their patterned goods, although most do not guarantee exact pattern match. Skilled responsible and competent craftsmen, who are experienced in the installation of patterned carpet, can effectively make adjustments within manufacturer tolerances to provide a successful installation. To assist this process, manufacturer tolerances must be clearly understood, communicated and agreed upon by all parties prior to the specification, bid, purchase and installation. There always must be an understanding about the additional carpet that must be allowed for pattern match.

23.1. Factors affecting an acceptable pattern match on the job site included, but are not limited to: the method of installation, the condition and levelness of the floor and the type of carpet backing system selected. It is imperative that all parties agree upon realistic levels of expectation before the carpet is installed.

24. Installation of pattered carpet requires more time and expertise often requiring the use of a power stretcher and additional staffing, this affecting the cost of installation.

25. Pattern size selection – Selecting larger patterns will facilitate matching ease.

26. 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.

27. Pattern adjustment – Pattern adjustment during installation is possible and should be anticipated.

28. 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.

29. 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 traffic can cause installation failure. Restrict carpet exposure to water from cleaning or other sources for a minimum of 30 days.

30. 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.

31. 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.

32. Seam preparation is more critical than anything you can do with a Wilton, and is taught in NFIC training course.

** If you have any questions, please call NFIC at 770  720-4537 **

Carpet Edge Preparation for Floor Inserts on Wilton’s:  To be shown in class.


***Seam preparation for Axminster, Velvet, and Wilton’s are demonstrated in the NFIC training course.****