Artificial grass installed on a poor foundation fails quickly. Seams lift, water pools, odors linger, and the turf sags underfoot. This guide walks through the materials, soil preparation, drainage design and finishing details that separate a durable installation from one that will disappoint within a season. Whether you are converting a Charlotte yard that has turned to mud under the summer heat and oak shade, preparing a dog run, or laying turf on a patio or rooftop, understanding what goes beneath and around the grass itself will help you ask the right questions and recognize solid work.
The Piedmont clay and red soil that underlies most Charlotte yards drains slowly and turns slick after a thunderstorm. A proper base, correctly graded and compacted, is the difference between a yard that sheds water and one that becomes a swamp. This guide covers infill types and amounts, base preparation on local soil, drainage principles, seam and edge finishing, and the written specification you should demand from any turf installer, including us.
Turf Infill Options: Silica, Coated Sand, Zeolite and Envirofill
Infill is the granular material spread across the turf surface after installation. It serves four critical jobs: it props the grass fibres upright so they feel and perform like real turf, it protects the backing from UV damage, it adds weight to keep the turf from shifting, and it helps water drain through the system. The most common infill is silica sand, a basic mineral ballast that is inexpensive and effective. Coated sand is silica sand treated with a polymer or mineral coating that rounds the grains, softens the feel underfoot, and often adds color to complement the turf blade. Both silica and coated sand are stable, long-lasting and widely used in residential yards.
Zeolite is a microporous mineral that absorbs moisture and odors, making it a popular choice for pet turf and dog run installations where urine smell and moisture retention are concerns. Antimicrobial and cooling coated infills, sold under brand names such as Envirofill, are engineered to inhibit bacterial growth and lower surface temperature in intense sun. Crumb rubber, made from recycled tires, is primarily a sports-field infill used in athletic and gym installations where impact absorption matters; it is not typical for residential yards. Your turf installer should specify the infill type and amount in writing, and explain why it suits your use.
How Much Infill Artificial Grass Needs, and Why
Infill is measured in pounds per square foot. A typical residential installation uses between 2 and 4 pounds per square foot, though the exact amount depends on the turf product, the pile height, the backing type, and the intended use. Heavier infill (toward 4 pounds per square foot or more) is common in pet areas and sports fields where durability and drainage under heavy use are critical. The infill accomplishes several things at once: it keeps the fibres standing upright and resilient, it shields the backing from ultraviolet light that can degrade it over time, it adds weight so the turf stays flat and does not shift in wind or foot traffic, and it fills the spaces between fibres to help water drain evenly across the surface. Too little infill is a common shortcut in cheap installations, and it shows within months as flattened, worn patches and as seams that lift because the turf lacks weight and support.
Ask your installer for the infill specification in writing before work begins. The spec should name the infill type (silica, coated sand, zeolite, or other), the target weight in pounds per square foot, and the delivery and spreading method. Do not accept vague promises like "we use quality infill." Ranges are normal because site conditions vary, but a professional installer will give you a specific target and will deliver it consistently across the entire yard.
What to Put Under Artificial Grass for Drainage
The path to good drainage starts before the turf goes down. First, the existing lawn or old turf and its root system must be removed entirely. Any remaining organic matter will decompose, creating voids that cause the turf to sink and puddle. Next comes excavation. The depth depends on your soil, your climate, and what the turf will be used for, but most residential installations require 2 to 4 inches of excavation to remove topsoil and reach stable subgrade. On a sloped lot, the excavation should follow the natural grade or be deliberately shaped to shed water away from the house and any pool or patio. A weed barrier (landscape fabric) can be laid at this stage to prevent weeds from growing up through the base, though it is not always necessary and should be discussed with your installer based on your yard's history.
Next comes the free-draining base layer, typically 3 to 4 inches of decomposed granite or crushed base rock, compacted in lifts (layers) with a plate compactor to create a firm, stable platform. This is where most cheap installations fail: the base is dumped, raked roughly level, and left uncompacted. An uncompacted base settles unevenly, creating dips and puddles that trap water and odor. After the base is compacted and graded, an optional draining underlay or pad can be installed, especially in pet areas, on patios, or in play zones where extra cushioning and drainage are valued. Finally, the turf is laid over this prepared surface. On hard surfaces like concrete or balconies, turf should never be glued flat to the slab; instead, a draining underlay or pad is used, with edge drainage to carry water away, so that no water sits trapped beneath the turf.
Base Prep on Charlotte Soil: Excavation, Base Rock and Compaction
Charlotte soil is dominated by Piedmont red clay and dense subsoil that drains poorly. After a summer thunderstorm, yards on ungraded clay turn to slick mud and stay wet for days. This is the soil condition that makes base preparation critical. Excavation removes the topsoil and organic matter and reaches stable subgrade, typically 2 to 4 inches down depending on the existing lawn depth. The excavated area is then graded so that water flows away from the house, the pool deck, and any low spots where water would collect. A slight slope (often 1 to 2 percent, or about 1 inch of drop per 4 to 8 feet of distance) is enough to shed water effectively without being noticeable underfoot.
The base layer itself is 3 to 4 inches of decomposed granite or crushed base rock, compacted firmly in lifts with a plate compactor. Compaction is not optional. Uncompacted base material settles over time, creating dips where water pools, and it provides no support for the turf, which then sags and becomes unstable. A plate compactor, run multiple times in overlapping passes, binds the base material into a solid, load-bearing platform. If your yard has a genuine water problem (a persistent wet spot, a low area that floods, or poor subsurface drainage), drainage must be addressed before turf is installed, or the job should not proceed. A well-prepared base on Charlotte clay will shed water reliably; a poorly compacted base will fail within the first heavy rain.
Artificial Grass Drainage and Underlay: Perforated vs Fully Permeable
Artificial turf drainage is described in two parts: the backing (the underside of the turf itself) and the base below it. The backing can be perforated, with small holes punched through, or fully permeable, meaning water passes through the material itself. Drainage rate is typically stated in gallons per hour per square foot. A fast-draining backing (12 to 20 gallons per hour per square foot or higher) is standard for residential turf, especially in climates with heavy rain or in pet areas where liquid volume is high. However, even the fastest-draining turf will fail if the base underneath does not drain. Water will accumulate in the base, the turf will feel spongy and unstable, and odors will develop because standing water prevents air circulation and infill from drying.
Underlays and pads serve specific purposes. On a hard surface like concrete, a patio, or a balcony, an underlay or pad provides cushioning and creates a drainage plane so water does not sit trapped between the turf and the slab. On a ground installation in a pet area or play zone, a pad adds comfort and can improve drainage in a marginal base. The underlay should itself be permeable and should direct water to the edges where it can run off. Ask your installer for the drainage rate of both the turf backing and any underlay in writing, and verify that the base material and compaction plan will actually shed water in your yard. A specification that names only "good drainage" is not specific enough.
Seams, Nails, Edging and Power Brooming
The finishing details reveal whether an installer understands the craft. Seams are the joints where two pieces of turf meet. A professional seam is joined with seam tape (a permeable adhesive strip) and turf adhesive applied to the backing, with the grain (the direction the fibres lean) aligned so the seam is invisible. The tape is pressed firmly into place and left to cure before the area is walked on. Nails or staples secure the perimeter and are spaced correctly (typically 6 to 8 inches apart) so the turf does not shift or pucker. A visible seam, a seam that lifts at the edges, or turf that moves underfoot signals poor workmanship or inadequate infill and base support.
Edges and perimeter finishing are equally important. Bender board (a flexible plastic or metal edging) is secured around the perimeter to create a clean line and to keep the turf from fraying or rolling back. On a patio or pool deck, the turf should be cut tight to the pavers or coping so water drains off cleanly and the edge does not catch a foot. After all seaming and edging is complete, the turf is power broomed. A power broom (a mechanical brush) stands the fibres upright, spreads the infill evenly across the surface, and gives the turf a finished appearance. Power brooming also helps the infill settle into the pile and improves drainage. A turf surface that looks flat, matted, or uneven, or that has visible seams or lifted edges, has not been finished properly.
What a Written Turf Spec Should Include
Before any work begins, ask your turf installer for a written specification that covers every material and method. The spec should include the turf product name and fibre type (polyethylene, polypropylene, nylon, or a blend), the face weight in ounces per square yard, the pile height in millimeters, the backing type and its drainage rate in gallons per hour per square foot, the infill type and target weight in pounds per square foot, the base material and depth (typically 3 to 4 inches), the base compaction method (plate compactor, in lifts), whether a weed barrier will be used, the seam method (tape and adhesive, with grain alignment), the edging type and method, cleanup and haul-off of old turf and excavated soil, and the workmanship warranty period (typically one to three years on the installation only). The spec should also note any site-specific conditions, such as slope, existing utilities, or drainage challenges.
A written spec is your protection. It tells you exactly what you are paying for, it gives you a standard against which to judge the finished work, and it creates accountability. A professional installer will provide it without hesitation. If an installer balks at putting the details in writing, or offers only a price per square foot with no material breakdown, move on. For pricing guidance and to discuss your specific yard, request a free on-site estimate, where measurements and conditions can be assessed and a detailed spec prepared for your approval.