How drainage works on concrete

Concrete does not absorb water, so your turf system must move water horizontally to a drain or vertically through planned weep points. Permeable turf backing lets water pass through. A drain mat under the turf creates channels so water can travel to the slab edge, a deck drain, scupper, or weep hole.

What a concrete-ready turf system includes

  • Drain mat or drainage cell layer 3/8 to 1/2 in thick that forms continuous flow channels.
  • Permeable artificial grass with punched or fully permeable backing.
  • A clear exit path for water: slab slope to drains or strategically placed weep holes.
  • Perimeter adhesive strategy that leaves intentional gaps at low points for water to escape.
  • Clean, stable edges and transitions that do not trap water.
  • Debris control to keep channels open and flowing.

Slope and weep hole options

  • Slope: Aim for 1 to 2 percent fall toward a drain. As a guide, 1/8 in per ft gets water moving.
  • Flat slab on grade: Add weep holes at low points so water in the drain mat can drop through to soil. Typical holes are 3/8 to 1/2 in diameter, spaced near low spots. Avoid undermining by keeping holes a safe distance from edges.
  • Balconies or roofs: Do not drill. Use a floating drain mat system and route water to existing scuppers or deck drains.

Installation steps for fast, reliable drainage

  1. Prep the slab: Verify slope, pressure wash, and remove high spots or loose coatings.
  2. Plan water exits: Identify the lowest edges, drains, or weep holes before you start.
  3. Lay the drain mat: Run channels toward the water exit. Tape or clip seams so channels stay continuous.
  4. Dry-fit turf: Unroll, rest, and align grain. Trim cleanly around edges and drains.
  5. Seam the turf: Use seam tape and adhesive under the seam only. Keep drain paths open.
  6. Perimeter bond: Apply exterior-grade turf adhesive in beads or strips around the perimeter, leaving deliberate gaps at low points for drainage.
  7. Infill and brush: Add appropriate infill, then power broom to stand fibers and open the backing pores.
  8. Water test: Hose the surface and confirm fast flow to exits. Adjust edge gaps if needed.

Pet performance and odor control on slabs

  • Choose permeable turf plus a drain mat so urine passes through and air can circulate.
  • Use antimicrobial or zeolite-based infill to reduce odor and support freshness.
  • Rinse regularly and apply enzyme cleaners for a clean, pet-ready surface.

Troubleshooting

  • Standing water at edges: Open or add drainage gaps in the perimeter adhesive at low points.
  • Pooling on the slab: Clear debris from channels, add targeted weep holes on slab-on-grade, or introduce a higher-profile drain mat.
  • Slow drying or odor: Increase rinse frequency, refresh infill, and improve airflow at edges.

Safety and compliance

  • Use exterior-rated, low-VOC adhesives suitable for concrete.
  • Keep drain inlets clear and guarded where needed.
  • On structures, follow building codes and waterproofing requirements. Do not penetrate membranes.

Specs at a glance

  • Slope target: 1 to 2 percent toward drains.
  • Drain mat: 3/8 to 1/2 in profile with continuous channels.
  • Turf backing: Permeable or fully permeable.
  • Adhesive: Perimeter beads with planned drainage gaps.
  • Infill: Choose for use case. For pets, consider antimicrobial or zeolite options.

When to use a floating system

On balconies and rooftops, build a floating assembly: drain mat plus permeable turf, fully contained and routed to scuppers or deck drains. No drilling and no membrane penetrations, just clean flow and a dry, durable surface.

Need help sizing the system?

Tell us your slab size, slope, and drain locations. FusionTurf will spec the right drain mat, turf, and adhesive pattern so your surface drains fast and plays great.