Landscape Architect Articles

Synthetic Turf:08-03-16 | News

Synthetic Turf:
Choose Your Adhesive Carefully

"Green strength" is an adhesive's ability to grab and hold two surfaces together at first contact, i.e., before it cures. High green strength helps prevent separation, curling, bubbling, lifting, creeping, slipping and wrinkling during outdoor synthetic turf installations. It also obviates the need to nail down the surfacing,replica watches which has inherent safety issues.

If you have ever specified synthetic turf or have considered specifying it, you should be aware of a couple of installation issues. This article discusses the importance of adhesive selection, plus, for safety reasons, avoiding metal nails in the installation of synthetic turf.

Most test results for installing synthetic turf reported by adhesive manufacturers are conducted under indoor conditions, but most synthetic turf installations are done outdoors and under variable weather conditions. There is much more to an adhesive than its ability to stick based on indoor applications. That's the major reason why that in outdoor conditions over time, there are so many synthetic turf failures, especially at the turf seams.

What follows are four important factors for successful outdoor installations: Three are about adhesives, and the fourth about the hazards of using metal nails to install synthetic turf:

1. The adhesive's ability to be used for installations in variable and sometimes adverse weather conditions is extremely important. Specifiers and installers should be aware of using an adhesive that can only be applied under narrow weather conditions. Installation delays can ensue if you use "fair weather only adhesives," because it's either too hot, too cold, to windy, or there's a possibility of rain, etc. This can delay an installation for hours or days, waiting for the weather conditions favorable for the adhesive. That's lost installation time and money.

The adhesive manufacturer's literature often lists the conditions in which the adhesive should not be stored before use and/or conditions when the adhesive cannot be applied. This is worth reading and checking beforehand, because you may be surprised at the narrow limits. If the manufacturer's literature doesn't address storage temperature limits and installation conditions limits, like temperature, rain just before or just after installation, etc., you need to ask.

2. An adhesive's high "green strength" during installation (not after it cures) is often the difference between an excellent vs. a not so good installation.
High green strength is the most important adhesive property during installation. Green strength (grab/tack as opposed to oily/slippery) is the property that gives an adhesive the ability to hold two surfaces together when first contacted and before (still green) the adhesive develops its ultimate bonding properties when fully cured. High green strength adhesives are vital for outdoor installations because they help overcome the tendency of surfaces like synthetic turf to separate, curl, bubble, lift, creep, slip and wrinkle during installation, without resorting to metal nails, excessive rolling and/or "sand bagging." Furthermore, a high green strength adhesive must be practical to handle widely variable weather conditions, including not only climate, but also hourly changes in weather conditions during the installation. Installers can't wait for ideal weather; they need an adhesive that can be used when it's hot, cold, damp, dry, windy, high humidity, low humidity, etc. An adhesive's high green strength (grab) at installation, before it cures, is essential to overcome the previously mentioned troublesome forces of "wind lift"; edge curl; creep; wrinkling; buoyancy from unexpected rain; expansion and/or contraction, which can result under variable temperatures. High green strength is the property that makes the other important "properties" in Important factor # 1 possible and successful. 3. The adhesive must have superior exterior durability after aging and weathering in all types of outdoor conditions After the installation is complete and the adhesive has cured, it must have excellent durability not only initially, but after aging and weathering under the day-to-day variable weather and climate conditions. Many adhesives initially give a good bond, which tends to fool many about aging, weathering and long-term durability. Not all adhesives are tested for those important long-term properties, hence, many adhesives deteriorate and fail, particularly in the seams.

4. Metal nails should never be used to permanently install turf. Nails can cause injuries: barefoot injuries from walking on the turf, and injuries from falling onto the turf. There is also the deadly infectious tetanus disease that derives from rusty nails. Additionally, three is a remote, but deadly possibility of lightning attracted to the metal nails.

In summary, safe, durable, long-lasting and profitable installations result when an adhesive can be applied and used in variable weather conditions; it has a high green strength; superior outdoor aging and weathering; and for safety reasons, does not require nails.

As seen in LASN magazine, August 2016.