How Do You Get Pet Urine Smell Out of Subfloors?
Last updated October 31, 2026
The short answer
Find the Affected Area
First, locate where the urine soaked in. Use a black light in a dark room to spot dried stains that glow. You can also trust your nose, but the black light is more precise, especially for old accidents on plywood or OSB subfloors. For a large area, work in sections so you don't miss any spots. If the subfloor is covered by carpet or tile, you may need to remove that layer to see the full extent of the staining. Remember that urine can wick sideways through the wood, so check a wider perimeter than the visible stain.
Once you find the spots, mark them with chalk or tape. This helps you focus your cleaning efforts and avoid missing any areas. If the urine has spread under walls or into joists, you may need to pull up more flooring to see the full extent. Check the subfloor's condition too, as heavy saturation can cause warping or weakening. For older homes, subflooring may be more porous, so the urine could have penetrated deeper. In that case, you might need to probe the wood with a screwdriver to check for softness, which indicates rot that requires replacement.
Clean with Enzyme Cleaners
Enzyme cleaners are the right tool for pet urine. They contain bacteria that digest uric acid, which is what causes the lingering smell. Apply the cleaner generously to the stained area, following the product's instructions for dwell time. Some enzyme products need to stay wet for several hours to work fully, so cover the area with plastic wrap to keep it moist. For the right results, use a product specifically designed for wood subfloors, as some formulas are too harsh for porous surfaces.
For heavy saturation, you might need to apply multiple treatments. After cleaning, let the area air dry completely. If the smell persists after drying, the urine may have crystallized deeper in the wood, requiring a stronger approach. In that case, you might consider sanding the surface or using a penetrating enzyme product designed for deep absorption. Sanding removes the top layer of wood that holds the crystals, but be careful not to sand too much and weaken the subfloor. If the urine has soaked into the joists, you may need to drill small holes to inject the enzyme directly into the wood.
Prevent Future Accidents
Once the subfloor is clean and dry, take steps to keep pets from repeating the behavior. Clean up any new accidents right away, and consider using a pet deterrent spray on the area. Also, make sure your pets have regular bathroom breaks. For persistent issues, a consistent routine can help reduce accidents, but the key is addressing the behavior early. You might also try confining your pet to a specific area until the habit is broken, and reward them for using the correct spot outside.
If you have a persistent marking issue, a veterinarian can rule out medical causes. Behavioral training may also help. Keep in mind that some pets mark due to stress or changes in the home, so identifying triggers can be useful. Patience and consistency are important, and you may need to try a few approaches before finding what works. For example, if your pet marks when left alone, separation anxiety could be the cause, and a professional trainer might offer guidance. Always clean accidents thoroughly to remove the scent, as lingering odors encourage repeat marking.
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Call Now (480) 898-4279Frequently asked questions
Can I use bleach to remove pet urine smell?
Bleach can kill bacteria but doesn't break down uric acid, so the smell often returns. It can also damage wood and create harmful fumes. Enzyme cleaners are safer and more effective for subfloors.
How long does it take to get rid of the smell?
The time varies based on how deep the urine soaked in. Cleaning with enzymes can take a few days to fully dry and neutralize. If you need to seal or replace the subfloor, expect the process to take longer.
Will the smell come back after cleaning?
If you didn't remove all the uric acid, the smell can return, especially in humid conditions. Sealing the subfloor helps prevent that, but if the urine soaked into the joists, you may need professional help.