Updated September 2025 • Urine Zero
Concrete is porous—cat urine soaks into pores and micro-cracks. This guide covers ventilation, sealed vs unsealed slabs, slow-flood saturation, 10–20 minute dwell, mixing 10X at 1:9, and edge-case troubleshooting.
Why garage concrete keeps smelling (even after you “clean” it)
Cat urine dries inside pores and micro-cracks. Surface perfumes and quick sprays don’t reach that depth, so odors reappear with heat/humidity. The fix is to contact the same depth the urine reached and keep it wet 10–20 minutes to work through pores—then let it dry fully.
Sealed vs unsealed (30-second drip test)
Drip water on a clean spot:
- Beads up → likely sealed. Expect more repeats and benefit from light agitation during dwell.
- Absorbs quickly → likely unsealed. Use a slow flood to drive solution into pores.
Map every hotspot (don’t miss edges)
- Cracks & control joints: urine travels along these—treat directly.
- Baseboards & wall bottoms: wick points—lay towels to protect, then overlap treatment 6–12 in from walls.
- UV/blacklight (optional): helpful for older stains—mark, then treat beyond the glow.
Step-by-step: remove cat urine odor from garage concrete
- Ventilate. Open doors/windows; run a fan for airflow.
- Prep. Dry sweep or rinse away dust/soil so product can reach pores; let standing water drain.
- Apply in evening/shade. Use a watering can or low-pressure sprayer to saturate slowly. Aim for ~¼–½ in penetration—don’t spot-mist.
- Keep damp 10–20 minutes. Re-mist lightly if it starts to dry. On sealed slabs, lightly agitate with a stiff brush to help contact.
- Air-dry completely. For old/severe odors, repeat in 12–24 hours. Sealed slabs may need 2–3 passes.
Cracks, joints & edges — how to treat them
- Control joints & cracks: run a slow stream directly into the groove; allow dwell; re-apply if needed.
- Perimeter edges/baseboards: apply carefully along the wall line; protect drywall/wood with towels.
- Thresholds & steps: treat overlaps and verticals; wipe drips on painted surfaces.
Coverage & severity (RTU)
Estimate how much ready-to-use solution you need. Adjust for porosity, weather, and odor age.
| Severity | RTU Rate (oz/sq ft) | Typical repeats | Notes |
|---|---|---|---|
| Light | ~0.4 | 1 pass | Fresh accident; unsealed slab |
| Moderate | ~0.8 | 2 passes (12–24 hrs apart) | Lingering smell; cracks/joints involved |
| Severe | ~1.5 | 2–3 passes | Old cat hotspots; topically sealed slab |
Using 10X Concentrate — mix 1:9
Mix 1 part concentrate : 9 parts water. Shake/stir the concentrate before diluting. Do not mix with other chemicals.
| Final Volume (RTU) | Concentrate | Water |
|---|---|---|
| 32 oz (sprayer) | 3.2 oz | 28.8 oz |
| 1 gallon (pump sprayer) | 12.8 oz | 115.2 oz |
Troubleshooting — if odor persists
- 24 hrs later still smells: increase depth (slower flood) and hold dwell closer to 20 min; repeat in evening.
- Only smells on hot days: residues remain deeper → expand the treatment radius.
- Smell moved to nearby area: likely wicking → overlap 12–24 in around hotspot.
- Sealed & stubborn: plan 2–3 passes with light agitation; let each pass dry fully.
- After odor is gone: optionally seal the slab (never seal odor in; deodorize first, then seal if you wish).
FAQ — Garage Concrete (Cat Urine)
Will bleach or vinegar work?
They can help on fresh accidents but often underperform on set-in odors and can create harsh fumes. Use a product designed to reach pores, keep it damp 10–20 minutes, and let it dry fully.
Do I need to rinse after it dries?
Not usually. If residue appears on adjacent surfaces, a light rinse the next day is fine. Allow full dry time before any rinse or next pass.
Is it safe around pets and kids?
Use as directed. Keep pets and children off treated areas until completely dry. Ventilate well during treatment and drying.
How many treatments will I need?
Fresh spots may resolve in one pass. Old hotspots or topically sealed slabs often need 2–3 passes spaced 12–24 hours apart.