At some point, every synthetic athletic field will need some repair. Changes within a site could also lead to more extensive work on the field surface. We’ve handled both situations at Brigham Young University, Provo, Utah.
The FieldTurf synthetic football practice field is going into its eighth year. Two synthetic fields were initially installed, replacing two of the four natural grass practice fields. BYU wanted the team to practice on a synthetic surface because other universities within the conference had installed synthetic game fields. As turf maintenance coordinator for BYU, my department is responsible for maintaining the fields, along with the natural grass fields, under the turf management program. I observed the installation by the supplier, because the better you know the components of the synthetic field, the more effective your work on that field will be.
|Photos courtesy of David Scholotthauer.|
|The sections for the fence posts are prepared, ready for tarping when the contractor arrives to auger in the post holes.|
On our fields, the irrigation system pipe and electrical conduit were installed after the existing field material was removed and the subbase was prepared, and before the installation work started. The supplier installed the drainage layer, installed and leveled the base material and installed the fabric, sewing in the seams. This is a poly-type fiber, 2.75 inches long with a 2.5-inch layer of infill, which is a combination of silicon sand and a very fine crumb rubber.
One of the installers gave instructions on field repair using glue for the sealing process. It’s a fairly simple process for minor repairs—the key is to keep the work area as small as possible to minimize disruption.
The most recent project on the synthetic surface took place during the summer of 2007. We installed a fence separating it from the natural grass fields to better protect and preserve those fields. We had 30 separate post installation sections. The majority required work within a 2-foot square. The bigger posts, to support the gates, required 3-foot squares. One section, where we needed to work with the irrigation piping and electrical conduit, covered an 8-by-4-foot rectangle. We also cut some narrow strips about 5 feet long to extend the irrigation piping for sprinkler heads just inside the fence at the center and both ends of that length of the field.
We plotted the area we needed to expose as a square or rectangle, keeping it as small as possible to limit disruption, but large enough to work in it effectively. We cleared away enough of the infill to be able to use a concrete saw to cut a slit through the fabric along three edges of the square. This gave us straight edges to work with and kept the section of the synthetic material linked in place along the uncut edge.
We rolled back the cut section, working from the cut edge toward the linked edge. For small sections, this step can be done by hand. For larger sections, we used a small loader to push and allow the material to roll back up on it. We moved slowly during this step, keeping the infill within the rolled section rather than allowing it to spill out along the sides. The weight of the fabric and infill material quickly became heavy, so we kept close watch on the process to avoid any damage to fabric.
For the fence post installations, we placed poly tarps around each hole to keep the material that would be pulled out by the auger from contaminating the infill of the surrounding area. An outside contractor did the auger work, extending the hole into the subsoil and pulling up dirt, road base and larger rock in the process. We removed that from inside the exposed area and on the tarps, then took up the tarps. The contractor set the fence posts and cemented them in place.
|A concrete saw is used to cut slits through the synthetic fabric.||As the flap of synthetic fabric is rolled back, push it into position for a tight fit at the slits, making sure it is level across the surface of the repaired area and level with the surrounding field surface.|
|Use a field tamp to compact and level the base material after the fence post has been inserted and cemented in.||With the flap of synthetic fabric rolled part way into place, staff members cut a slit so they can work the fabric around the fence post.|
The next step was filling the exposed areas back in properly, making sure they were compacted and level. We used the landscape rakes and tamps that we usually use to work the baseball infield and mound for this process. The larger the area and greater the disruption, the harder it is to rework this area. For the post holes, we used a 2×4 board laid across the section to ensure it was level within the exposed area and lined up with the rest of the field along the edges.
We wanted to lift the edge of the intact section of the synthetic to slip in the patch fabric to extend beyond both sides of the seam created at the point of the slit. Even with a small area, it can take two or three people to hold up that edge because of the weight of the infill. Anything that pushes against the material beneath the surface can build up a little ridge. We worked carefully along the edge to keep that from happening.
Once the patch fabric was in place, we used a hand caulking gun filled with regular waterproof industrial adhesive to put a bead of glue on the patch just beyond the edge of the synthetic surface. We carefully lowered the edge back into position.
The adhesive requires 48 hours to set up and become waterproof, so we had to work this step around the weather and any irrigation that might affect the area.
Once the patch material was firmly glued around all three sides of the exposed area, we again used the caulking gun to put a bead of glue on the patch material around the three edges of the exposed area, just outside the slit. For the post installation, we also needed to cut a slit in the synthetic surface material in order to work it around the post as we put it back in place.
Then, we rolled the flap of the field back into place, pushed it into position for a tight fit at the slits and made sure it was level all across the surface. We tracked the weather and irrigation schedules for this step, too. The synthetic fibers and the infill material both need to be dry or the infill will stick together in globs and stick to the fibers instead of filtering down to the surface.
Once the procedure was completed, we resumed our regular maintenance practices, making sure to alternate the direction of our grooming with each procedure to keep the fibers standing upright.
David Schlotthauer has worked for the grounds department of Brigham Young University since 1979.