Glass fiber textile

by brittney_cutler | March 4, 2022 3:00 pm

[1]

Outdoor lifestyle is crucial to commercial buildings

By Julian Campy and Steven H. Miller, CDT

In the mid-20^th century, drywall swept through the U.S. construction industry and made the interior plastering trade outdated. For more than six decades, the last step in installing drywall has been a process of spackling and sanding to smooth over heads of fasteners and joints between the wall panels. While this method of finishing has changed little during that time, the cost of labor has increased, more so than the cost of materials. As a result, the labor-intensive and dirty process of finishing ready-to-paint drywall has gotten much more expensive.

As the construction industry heads into another year with a shortage of qualified labor, the upward trend in labor costs is expected to continue, and the quality of workmanship is likely to decline as less-qualified labor must be hired. It is an appropriate time to consider less labor-intensive options for wall finishing.

A technique widely used in Europe can eliminate common defects on both walls and ceilings, and offers a cleaner, faster, more efficient finishing process. Instead of applying three coats of joint compound to smooth a wall, glass fiber textile is adhered to the entire drywall surface. It can be applied over a very low-level drywall finish, saving time and labor, and achieving the equivalent of the highest level of drywall finish at lower costs. The application procedure is fast, easy, and requires little training to master. Walls and ceilings are finished and ready to paint faster.

[2]

Glass fabric-clad walls have numerous performance characteristics which make them an improvement over bare drywall, and they are available in a broad range of engaging aesthetic options that go far beyond smooth. This method of wall finishing has been common in Europe for decades, where hundreds of millions of square meters are applied to walls and ceilings every year. It has only recently emerged in the U.S. Glass fiber textile walls have been applied in numerous Starbucks locations in at least six states (Florida, Mississippi, Alabama, Louisiana, Massachusetts, and Nevada). They provide a damage-resistant solution in high traffic locations such as seating areas, corridors leading to bathrooms, and in the retail store, while also creating an attractive appearance.

Drywall finishing standards

A smooth wall, painted or papered, is the norm for interiors in the U.S. Walls featuring wood paneling, exposed brick, or glass are also common, but they are still special finishes. The baseline is a hard, smooth, opaque painted wall. It is often made of drywall—gypsum board panels or, less frequently, magnesium oxide panels. These panels have smooth surfaces. To render the panel-to-panel transitions just as smooth, a system of taping and smoothing with joint compound has evolved, with standards for how to apply it. For instance, GA-216 Application and Finishing of Gypsum Panel Products and GA-214 Recommended Levels of Finish for Gypsum Board, Glass Mat and Fiber‐Reinforced Gypsum Panels, published by the Gypsum Association detail how to install and finish drywall. Much of this is also incorporated into ASTM C480 Standard Specification for Application and Finishing of Gypsum Board.

GA-214 lays out five levels of finish using tape and joint compound (mud), with increasing degrees of smoothness appropriate to different types of applications, from the simple Level 1 for walls that will generally be concealed from public view to Level 4 and Level 5 for painted and wall-papered interiors. A modified version of the levels of finish is included in ASTM C480 as Appendix X8.

[3]

These finishes can be thought of as the five levels of smoothness, or as levels of allowable imperfection. Level 4 is intended for appearance areas where smooth walls are decorated with flat paints, light texture coatings, non‐continuous textures, or wallcoverings. Level 4 is the minimum acceptable finish for painting or for wall coverings that will reveal imperfections in substrate smoothness. The standard requires three coats of joint compound on the joints and fastener heads, each wider than the previous coat, and each sanded in between coats. The third coat on the joints must be spread 152 mm (6 in.) from the joint center on each side. On a 1219-mm (48-in.) wide panel, joint compound will cover 25 percent of the board surface. The three coats over the fastener heads and accessories effectively increases the covered area to about 30 to 35 percent. Each layer must be allowed time to set or dry, and then sanded smooth. After three coats, a layer of drywall primer is necessary, prior to painting, primer, and finish coats.

Level 5 is intended for walls decorated with semi-matte and gloss paints or other glossy decorative finishes, dark/deep tone paints, or walls where there are critical lighting conditions. Side-lighting on walls or ceilings, whether natural or artificial, creates so-called critical lighting conditions as it makes any texture or unevenness in the surface cast sharp shadows. Level 5 requires all the same work done for the Level 4, plus a skim coat of joint compound that covers 100 percent of the wall, which also must be sanded. Obviously, these operations are labor intensive. Labor accounts for approximately 75 percent or more of the cost of hanging and finishing drywall, depending on the local labor market. The finishing cost is entirely labor.

They are also time-consuming, with waiting periods for joint compound to harden, and extensive time sanding between coats. The dust created by sanding also tends to deter other trades from working in the space, so everything else stops while drywall finishing is underway. The drawn-out length of the finishing process increases costs related to the construction schedule.

[4]

The existence of five different finishing levels, as opposed to a single standard, is an accommodation to save money on walls whose substrate will not be publicly visible, either because it is completely concealed by a wall covering, or it is not in an occupied area. This is an indirect acknowledgement of the excessive cost of finishing drywall for appearance.

The glass fiber textile alternative

An alternate approach to achieve the equivalent of a Level 5 finish is to cover the wall with a paintable fabric. It is much faster and less labor-intensive than a joint compound finish and, even with a higher material cost for fabric, it is less expensive overall.

Glass fiber textile, either unwoven or woven, can be adhered to the wall with a seamless appearance, and then painted or papered. Depending on the fabric, it can achieve a smooth surface or a perfectly textured surface, with a wide variety of weaves available for different appearances and special performance applications. Whether the finish is smooth or textured, the surface is consistent and contiguous. It can be painted as though it were drywall. Pre-primed products take paint better than drywall does and can save significant cost and time on painting by reducing the number of coats needed to cover the wall.

Applying a smooth, non-woven glass fiber textile—sometimes referred to as fleece—effectively conceals fine details in the drywall substrate but presents a similarly textureless wall surface. If the drywall is brought to a Level 1 or Level 2 finish and then covered in glass fleece, it will present a defect-free surface equivalent to a Level 5 drywall finish. It also makes the surface stronger and more resistant to abuse and damage.

How it works

To finish a wall or ceiling with glass fiber textile, the drywall should first be brought to a Level 2 finish: panel joints taped by embedment in joint compound and wiped with a knife to leave a thin coat of compound over the tape; and fastener heads covered with one coat of compound.

[5]

The wall is primed with a sealer, typically using a low-pressure sprayer, to remove excess dust and prepare the surface for proper bonding with the textile glue. Then, fabric is adhered to the wall. Glass fiber textile is available pre-glued or unglued. For an unglued fabric, the adhesive is spread onto the wall using a paint roller, like dry-hanging wallpaper. Both starch-based and vinyl-based adhesives are suitable. Most glass fiber textile is supplied in rolls, typically 991 mm (39 in.) wide. A length of fabric equal to the ceiling height plus 51 to 100 mm extra (2 to 4 in.) is cut from the roll and hung on the wall. The fabric is smoothed down to the wall with a roller or a specially designed spatula, being careful to remove any wrinkles, bulges, or air pockets. Glass fiber textile can be repositioned for some time before the adhesive sets; exact working time is dependent on the specific adhesive and the ambient temperature and humidity.

Pre-glued glass fiber textile offers increased labor and time savings. Instead of applying glue to the wall and then hanging the fabric, the material has a backing of water-activated adhesive that is factory-applied. One manufacturer even offers a wetting station that mounts a fabric roll and dips the fabric in a water bath as it is being unrolled. Once wetted, the adhesive is immediately ready, and the fabric can be applied to wall as soon as it is cut. The adhesive allows repositioning, like adhesives used with unglued materials. The adhesive has a working time of approximately 30 minutes. If the sheet is not hung soon after wetting and the adhesive dries out, it can be rewetted once. The glass textile is ready for paint when it is dry, usually six to eight hours.

To eliminate visible seams between sheets of fabric, adjacent sheets can either be butt-joined, or overlapped and double cut. The fabric takes well to a simple butt-joint, and it does not shrink, so the seams stay closed. Adjacent sheets can also be overlapped by 51 mm (2 in.) and then trimmed through both layers to get an exact edge-match. Fleeces can be trimmed with a straight vertical cut from ceiling to floor using a sharp knife, with care to not cut into the surface of the drywall. For woven fabrics, a wavy cut helps blend the two sheets of fabric and eliminate a visible joint. The trimmed edge is removed from the top layer, and the trimmed edge of the layer underneath is slipped out from behind, so the fabric can be smoothed down to adhere to the wall, leaving a seamless appearance. Any adhesive on the front of the fabric can be wiped off with a damp rag.

Decorative and performance options

In addition to non-woven glass fleece, glass fiber textile is also made in a broad variety of woven patterns that produce textured walls, as opposed to purely flat surfaces. It is an upgrade that incurs a moderate increase in material cost. Application is the same as non-woven fabrics. A broad range of woven textured fabrics are also available pre-glued.

There are decorative weaves that feature a textile look, as well as geometric patterns. Irregular patterns and even custom graphics (such as corporate logos) can also be woven in thanks to computer-controlled jacquard weaving machines. Non-woven fabrics are also imprinted with sand to produce irregularly textured surfaces, geometric patterns, and even large, repeating designs.

Fabrics designed with specialized performance properties offer abuse resistance, acoustic and thermal insulation, fire resistance, or magnetic walls. Extra heavy fabrics, often labeled as renovation materials, are made to conceal damaged or uneven substrate walls. Woven and non-woven glass fiber textiles can be used on a variety of substrates, not just drywall. Block walls or plaster are also compatible or can be prepared economically to take a smooth fabric finish. Fabrics designed for renovations can even conceal existing tile walls.

[6]

Saving time

Once fabric is applied, the wall is ready to paint or paper. There are no additional layers to apply, no sanding needed. Where a Level 5 drywall finish typically requires several days of repeated coating and sanding, a glass fiber textile finish dramatically reduces time between hanging the drywall and painting. A typical production rate for drywall finishing is 3 m² (30 sf) per labor hour. Glass fiber textile with pre-glued backing raises it to approximately 28 m² (300 sf) per labor hour. This can dramatically reduce the number of days the job takes.

Since glass fiber textile does not need to be sanded, it is a dustless application. Joint compound finishing produces significant dust during sanding, and generally makes it incompatible with other trades working in the same space, so all other work is delayed. A fabric finish bypasses these delays and makes the task far easier to coordinate with other trades. Faster application and greater compatibility with other trades can have an accelerating effect on construction and renovation schedules, a significant benefit to the owner. The property is ready to be occupied (and producing income) more quickly, and a number of time-related construction costs (e.g. insurance, interest) are reduced.

The dust from drywall finishing requires a major cleaning of the space afterwards, often performed by a specialized cleaning crew. Glass fiber textile eliminates most of the cleaning expense and delay associated with joint compound finishing.

Application is an environmentally friendly process, since there is no sanding necessary and, therefore, little or no impact on indoor air quality (IAQ). Volatile organic compound (VOC) emissions may depend on the adhesive being used, whether it is roll-on adhesive or pre-glued fabric. Pre-glued products are available that have exceptionally low VOC emissions (0.01g/L [0.002 oz/gal] or less after three days).

Improved performance

In addition to saving on labor cost and reducing construction time, glass fiber textile imparts several performance benefits to the finished wall. Pre-primed glass fiber textiles:

Take paint better than finished drywall, which can enhance the quality of the paint job and may reduce the number of coats necessary to fully cover, saving time, material, and labor costs;

Increase impact and abuse resistance;

Increase crack resistance;

Increase fire resistance since, unlike the paper facing of drywall, it is a non-combustible material;

Are water vapor permeable, allowing the wall to breathe; and

Do not support the growth of mold.

Other performance enhancements such as noise reduction or thermal isolation may be obtained by use of specialized glass fabrics.

Managing cost

The cost of joint compound finishing is mostly labor. Materials amount to a small fraction of the total. Labor rates vary by region. Recent, informal online surveys suggest many contractors in the U.S. are paying more than $2 per square foot for drywall installation finished to Level 5. That cost is comprised of all materials including the drywall itself, and labor to hang the drywall, tape it, mud it, and sand it for three coats, and clean up the dust produced by sanding.

In this calculation, the cost of the drywall material and labor to hang it and bring it to a Level 2 finish is 96 cents. Those steps, and costs, are common to both a joint compound finish and a glass fiber textile finish. The remainder of the cost to bring it to a Level 5 joint compound finish, cleaned and ready to paint, is almost entirely labor. Materials—joint compound—account for about four cents. If many contractors are paying more than $2, it means the cost above Level 2 is $1 or more.

The cost of glass fiber textile application is mostly materials, especially if pre-glued fabrics are used. Pre-glued materials eliminate the step of spreading adhesive on the wall, which lowers labor cost by about 25 percent. Non-woven glass fleece, pre-glued, costs about 65 cents per square foot (woven, textured pre-glued fabrics start at about 85 cents per square foot). Application labor is the same for either type of material, seven cents per square foot. The cost above Level 2, including fabric application and minimal cleaning, for a Level 5 ready-to-paint wall, is about 81 cents per square foot. That is 20 percent less than joint compound finishing, depending on local labor rates. Even some woven, textured fabric options would still be cost-competitive with a Level 5 joint compound finish, despite the increase in material cost.

In addition, there is a significant savings in time, which affects other costs in the project. Time saved in comparison to joint compound finishing is greater than 65 percent. A job two workers can finish in one day applying a pre-glued fabric would typically take four workers and three days for a Level 5 joint compound finish.

Conclusion

When specifying glass fiber textile, select products by their performance properties. Pre-glued materials will be the most cost-effective and timesaving. For basic smooth walls over new drywall, select thin, non-woven fleeces that cover all small imperfections and create a paintable, smooth surface. For rough, damaged, or uneven substrates, look for renovation fabrics, thicker, heavy woven materials that can cover significant unevenness and cracking. Magnetic whiteboard fabrics may save money in finishing classrooms and conference rooms. Fabrics with sound-absorbing and thermal insulating properties can be selected to help control acoustically active spaces where sound clarity is important, or to increase thermal isolation; materials should have noise reduction coefficient (NRC) ratings or R-value ratings, as appropriate.

By selecting patterned woven fabrics instead of smooth fleeces, designers can upgrade the aesthetic quality of the wall surface, and a vast array of fabric patterns are available. This method of preparing walls empowers designers to make rooms that are more visually engaging, a luxury finish that does not increase the budget.

Authors

Julian Campy is a civil engineer specializing in construction, with more than 15 years of industry experience. He is co-founder of Nordic Look USA, an exclusive distributor in the Americas of Systexx premium pre-glued glass fiber textiles for walls and ceilings. He can be reached via email at jcampy@nordiclookusa.com.

Steven H. Miller is a journalist and marketing consultant, who has specialized in construction industry issues for the past 14 years. He can be reached via email at steve@metaphorce.com.

 

Source URL: https://www.constructionspecifier.com/glass-fiber-textile/

---