How to Treat a Plywood Subfloor for Urine – The Ultimate How-To Guide 2024

How to Treat a Plywood Subfloor for Urine

To treat a plywood subfloor for urine, you will need to assess the damage, remove dirt and debris, wash and seal the subfloor using a cleaner, and repair any damage. Our ultimate guide has all the details you need to get started.

Why Do We Need to Treat a Plywood Subfloor for Urine?

We treat a plywood subfloor for urine to maintain a clean and odor-free environment. Without proper treatment, urine residue can seep into the subfloor, causing persistent odor and potential damage. Untreated urine can cause bacteria and allergens to build up, posing health risks.

Assessing the Damage

Begin by examining the plywood subfloor for any signs of urine stains and lingering odors. Pay close attention to corners, edges, and areas near baseboards where urine may have seeped through. Look for discoloration, soft spots, or areas with a particularly strong odor.

Pre-Cleaning the Subfloor

Removing Surface Contaminants

Before cleaning the urine, you need to clean any loose debris, dirt, and dust. Thoroughly sweeping or vacuuming the entire surface area will ensure that the subfloor is free of any particles that could interfere with the cleaning process.

Washing with Cleanser

Once the surface contaminants are removed, select a mild detergent for cleaning. Apply the detergent evenly across the subfloor, paying particular attention to areas with visible staining or strong odors. The detergent removes any stubborn stains or odors.

Rinse and Dry

It’s important to rinse the subfloor thoroughly with clean water. Use a mop or sponge to cover and clean the entire area, ensuring that all traces of the detergent are removed. Allow the subfloor to air dry completely before moving on. This ensures that the subfloor is completely clean and ready.

Treating Urine Stains and Odors

Enzymatic Cleaner

These cleaners contain enzymes that target and digest organic matter, helping to eliminate smells. Apply the cleaner generously to the affected areas. Follow the instructions on the cleaner for exact timings.

Odor Sealers

These form a protective barrier that trap lingering odors, stopping them from spreading into the new carpet. Apply the sealer evenly over the subfloor, concentrating on spots with strong smells or stubborn stains. Let the sealer dry completely before moving on to installing the carpet.

Repairing Damaged Areas

Sanding and Patching

Smooth out any rough or damaged spots on the subfloor by sanding them down. This helps create a level surface for the new carpet. Patch up any holes or gouges in the plywood subfloor to prevent unevenness.

Applying Sealant

Seal damaged areas with a suitable wood primer or sealant. This helps the subfloor to absorb carpet adhesive evenly. Apply the sealant evenly over the repaired areas and allow it to dry completely.

Tips to treat a plywood subfloor for urine


Open windows and doors if possible, and use fans or dehumidifiers to circulate air. This helps things to dry more quickly, while also getting rid of the urine smell and preventing any breathing issues.

Professional Consultation

If the urine damage is extensive, you may need to call a professional who can provide guidance on the most effective treatment methods. Their expertise can help ensure that the subfloor is properly restored.

Safety Precautions

Wear protective gear such as gloves and masks to prevent skin contact and inhalation of potentially harmful fumes. Follow the manufacturer’s instructions carefully and take precautions to minimize exposure to any hazardous substances.

Final Inspection

Perform a final inspection of the subfloor to verify that all urine stains and odors have been effectively treated. Check for any discoloration or smells. Once the subfloor is clean, dry, and properly sealed with no signs of damage, you are ready to continue with your project.

Got more questions? We have answers!

Plywood Subfloor – How to Install