Two months after installing 320 sq ft of turf in my backyard, a soft spot formed near the patio door — right where both dogs kept turning sharply on their way outside. This is the specific failure, why it happens, and the fix that’s held for a full year since.
Why Turf Sinks After Installation
Sinking almost always traces back to the base layer, not the turf itself. If the crushed base material underneath wasn’t compacted to a stable, even density, normal foot traffic will keep compressing it unevenly for months after installation — long after the job looked “done.”
The Real Cause: Dry Compaction
In my case, I compacted a 3-inch layer of class II road base while it was bone dry. Dry base material shifts under a plate compactor instead of locking together — the surface looks flat right after, but it has no real structural stability. Two months of dogs pivoting in one spot was enough to expose it.
The Fix That Actually Held
- Pulled up a 6×6 ft section of turf around the sunken area.
- Broke up and removed the loose base material.
- Re-laid road base in 1-inch lifts, lightly wetting each lift before compacting — damp enough to hold a shape when squeezed by hand, not soaked.
- Re-compacted each lift separately rather than the full depth at once.
- Re-seamed the turf back into place and re-brushed the infill.
Total cost for the repair: about $60 in materials and a lost Saturday. It’s held with no further sinking for over a year, including through last year’s rainy season.
How to Prevent It the First Time
Water the base lightly before compacting — enough that a handful holds together, not so much that it’s muddy. Compact in 1-inch lifts rather than all 3 inches at once, and pay particular attention to any spot where traffic will pivot or concentrate, like doorways and gate paths — those need extra compaction passes, not just extra base depth.