Water-Damage Bathroom Floor. Tips from professionals
When it comes to property damage, water is one of the worst types. Even in a bathroom built to cope with water, it can do a lot of damage when water finds its way under the floor. If not dealt with in time, it can lead to mold. And worse case, it can damage the floor’s structural integrity, subfloor, and electrical wiring that runs through the floor or substructure.
Water-Damaged Bathroom Floor
A musty stench, mildew, damaged floors, baseboards, and walls are all bathroom floor water damage signs. If you notice any signs, the first step is to find the leak. The source can be inside the bathroom or outside the bathroom. Even the smallest amounts of water can cause irrevocable damage and dangerous mold growth if left for extended periods. Depending on the scale of the damage and the used flooring material, you will need to replace part of the floor.

This article will provide you with tips and tricks to help you deal with water damage on your bathroom floor and ceiling. How can you detect water damage to your bathroom floor and prevent it.
Contents
- 1 How to Spot Water Damage to Your Bathroom Floor
- 2 Categories of Water Damage to Your Bathroom
- 3 How to fix a water-damaged bathroom floor
- 4 Water on Bathroom Floor but No Leak
- 5 Water Damage Bathroom Ceiling
- 6 Bathroom Floor Repair around Toilet
- 7 How to Replace a Rotted Bathroom Floor
- 8 How Do I Get Water Out from Under My Tile Floor?
- 9 How To Prevent Water Damage in Your Bathroom
- 9.1 ● Inspect your plumbing regularly:
- 9.2 ● Toilet and sink clog:
- 9.3 ● Keep it clean and well ventilated:
- 9.4 ● Repair damage as soon as you notice it:
- 9.5 Frequently Asked Questions:
- 9.6 ● Can steamy showers damage my bathroom floor and walls?
- 9.7 ● How much does it cost to replace or repair a water-damaged floor?
How to Spot Water Damage to Your Bathroom Floor
It’s easy to miss water damage to your bathroom floor primarily because of how the flooring is built. A bathroom floor is such that it can cope with water spillage. But when water finds its way under the floor, certain signs can show this. Of course, every situation is different, and it greatly depends on things like the substrate and floor type:
- Bulging tiles or floor: If you notice loose or bulging tiles, it can mean that there is a problem with the substrate. Water damage is a common reason for this.
- Spongy floor: You can notice this when you walk on it.
- Damaged grout and caulk: Damaged or missing grout can lead to water finding its way under the tiles.
- Mold and mildew: When there is moisture under the floor, it can lead to mold and mildew that continuously returns. Mold can also start with poor ventilation, so it does not always mean that there is water damage.
- Tile discoloration: Discoloration of your bathroom floor tiles
Categories of Water Damage to Your Bathroom
While dealing with water damage to your bathroom floor, it is good to know that water damage can be divided into three categories, based on the degree of contamination. These categorizations are:
● Category 1: Clean water
Category 1 is clean, well-maintained water sources like an overflowing sink that are far easier to deal with quickly without the risk of adverse effects on your health.
– What to Do:
Dry water puddles on your bathroom floor and fix the source of the leak before identifying the extent of the damage.
● Category 2: Dirty water
Category 2 includes a toilet with pee (no human waste), sump pump backup water, and hydrostatic pressure seepage such as water leaking through the slabs or damaged floor tile grouts. While coming into touch with this water category may not be very dangerous, removing any contaminated items and sanitizing them entirely is necessary.
– What to Do:
If you decide to get rid of the puddles yourself, make sure to wear gloves, boots, goggles, protective clothing, and a respirator to avoid getting into direct contact with contaminated water.
● Category 3: Dirty water with human waste
Category 3 includes water damage from toilet water with excrement, water with microbiological growth, usually soaking through sheetrock of drywall, and eventually dripping to the bathroom floor. This category damages your bathroom floor and can also cause severe sickness or even death.
– What to Do:
Wear protective gear, and ensure proper ventilation. If there is a lot of water damage, I recommend asking a professional for help.
How to fix a water-damaged bathroom floor
Over time, undetected leaks, increased humidity, and seeping may cause even the most resilient and waterproof flooring to fail. Fixing a water-damaged bathroom floor depends on the type of flooring. Here’s how to fix different bathroom floor materials:
● Water damaged Vinyl Flooring
While vinyl floors are resilient, buckling on your bathroom vinyl floor might be a sign of water damage. Before repairing the damaged area, make sure to clean the surface first.
Cut out the damaged vinyl using a sharp knife before prying it off the floor. Finally, dry out the floor before replacing it with some spare vinyl or reusing it.
● Water damaged Tile Flooring
Tile flooring is a popular bathroom choice in most homes. The tiles can either be ceramic or porcelain. When water gets underneath tiles, it causes them to detach from the subflooring. This means that cracks on the ceramic or loose tiles can identify water-damaged bathroom floors.
If you have ceramic tiles, lift the loose tiles, pry them up from the floor, and clean them up. Dry up the subfloor before resetting the tiles if they are not broken. If damaged, replace with new tiles and apply matching grout to secure them to the bathroom floor. A similar process applies to porcelain tiles. I recommend using waterproof tile adhesive.
● Water damaged Cork Flooring
The first signs of water damage to cork flooring would include stains on your bathroom floor. Water can also loosen the glue between the cork and the substrate, loosening the cork. This, in turn, often will damage your floor, and it will cause the floor to appear warped or as if it’s lifting from the floor.
If the damaged area contains some small holes, you can try to patch it using some spare cork or wood filler. If the damage is widespread, you may have to replace whole cork planks. Start by carving out the cork plank from the floor using a hammer or chisel. If the adhesive is still strong, you will need to damage the plank to remove it. Next, put the new cork tiles with a new adhesive and paint over the repaired area with a layer of a protective finisher.
Water on Bathroom Floor but No Leak
If you notice water on your bathroom floor but no apparent leaks, it probably means the water is coming from a source outside of the bathroom, or there is a problem with condensation. It may be a plumbing leak inside a bathroom appliance, a damaged pipe, a roof-wall junction flashing failure, or a roof or siding leakage. In case of condensation, it will probably be one of the bathroom appliances.
● Invisible leak
The best approach to finding an invisible leak is to determine when the leak is getting worse. This process will take some time because you have to wait until the results are visible. If the leak is large, it is easy to find and not invisible.
If you notice more water after you flush the toilet having a shower, it is probably a problem with the appliance. It will probably be a leak in the roof or wall if it worsens during or soon after rain. Turn off the mains, and see what happens. It may be a pipe issue if you notice it is getting better.
● Condensation
It is also possible that not a leak but condensation is the reason. Differences in temperature in the toilet tank can result in condensation on the tank’s surface. The condensed water may drip down the tank’s exterior and settle on your bathroom floor around the toilet. Use toilet tank liners or anti-sweat toilet tank valves to deal with toilet tank condensation.
● Hydrostatic leakage
There might also be a hydrostatic leakage in your home, causing water to wind up your bathroom floor through the tile grout joints. If you suspect this is the case, reach out to an expert for a plumbing system inspection.
Water Damage Bathroom Ceiling
Water damage on your bathroom ceiling often results in water drips coming in through cracks in the ceiling onto your floor. Other signs include discolored growths, bulging drywall, a sagging ceiling, and visible discolorations.
Due to the temperatures in your bathroom, and the fact that it is an area prone to water damage, most of these water damages on the ceiling are long-standing rather than one-time incidents. If you have drywall or plaster ceiling, water damage can result from rainwater leaking through the roof of your home.
It can also result from a leaking pipe that runs through an upper floor or the attic. To remedy the situation, start by removing the damaged ceiling materials and drying them. Or try to access the area from the floor above.
Check if you see any evidence of mold. I recommend wearing safety goggles and a dust mask until you are sure there is no danger. If the ceiling is made from drywall and is entirely wet, you can easily tear out the affected area. But if it is only stained, cut out the damaged portion and replace it with a new piece of drywall. Remove and replace any damp insulation if the leaks are from the roof or attic.
Bathroom Floor Repair around Toilet
The toilet must be removed before installing new flooring in the bathroom. You can do so using the following steps:
● Step 1: Turn off the water supply
To begin, turn off the water supply to the tank. Then flush the tank to remove any remaining waste. Sponge-squeeze the remaining water from the tank into a pail.
● Step 2: Remove the toilet
Remove the bolts on either side of the bowl base. After that, straddle and hoist the toilet. If needed, remove the bolts connecting the tank and bowl.
Scrape the wax ring off the mounting flange with a utility knife. And remember to stuff the drain with old rags to keep out sewer gases and debris.
● Step 3: Check the floor
Strip a piece of the flooring to examine how far the damaged floor spreads. For this process, you’ll need a putty knife for vinyl a tile removal equipment for porcelain and ceramic tiles.
Remove the flooring a few inches past the rotting spot. To test the rotting subflooring, use a screwdriver or claw hammer. If bad, pry it out and use a jigsaw or a hand saw to out the damaged parts. Finally, replace them.
● Step 4: Remove the substrate
Cut a square in the damaged substrate around the water-damaged area around the toilet. Next, assess the gap and ensure the cut sides are over the center point of a joist. Doing so will allow you to cut and install a plywood repair.
Cut plywood pieces long enough to accommodate under the cuts and floor joists, preferably 2”x 6″. You can use a power screwdriver and add exterior-grade screws to attach the pieces to the floor joists.
Proceed to cut plywood portions to fit the aperture and cut it along the flange’s midline. Make a split circle at every plywood half big enough for the flange. After that, bolt the exterior-grade screws fasten the plywood to the floor joists as you ensure the screws are about 4 inches asunder.
● Step 5: Reattach the toilet
First, smoothen the floor where the toilet will sit. Use wood filler if needed. You should cover subfloor gaps to prevent them from showing up in the final flooring. Return the toilet correctly back to its original location on the new subfloor. Check that all the pipes fit correctly and are tight. If needed, replace seals that you suspect are the reason for the original leakage.
How to Replace a Rotted Bathroom Floor
Signs of a rotting bathroom floor and subfloor can be squishy flooring. You will also notice a dump, musty smell coming off from rotting wood. A rotting floor is a sign that the water problem has been there for some time.
Before you start replacing your rotting bathroom floor yourself, ensure that you have fixed the water problem. Use the following steps to replace a rotted bathroom floor:
● Step 1: Remove Bathroom Fixtures
Remove any bathroom fixtures, such as toilets, sinks, cabinetry, or the shower that may be in the way. What you have to remove will depend on the scale of the floor damage. But I recommend removing more than what looks damaged on the top. You want to ensure that there is no damage at the bottom.
● Step 2: Get rid of the floor and the underlayment
When removing the rotten bathroom floor, begin at the wall and work your way in. Remove the molding along the wall first. Then continue removing the main area. If applicable, remove the underlayment.
● Step 3: Inspect the Subfloor
If the subfloor is also damaged or rotting, you may detach the nails or screws for the subfloor using a hammer or screwdriver and then pull the plywood panels off the joists with a pry bar.
● Step 4: Replace Rotten Flooring and Joists
You can also inspect the plumbing underneath your bathroom floor with an exposed subfloor and fix all leakages. Then, use a circular saw to cut out the damaged parts of the subfloor and replace them with new floorboards or plywood. Ensure that the floor joists are fine, else they need to be replaced first.
How Do I Get Water Out from Under My Tile Floor?
Follow the following steps to get water out from under your tile floor.
● Step 1: Get rid of excess moisture on the tile’s surface
Dry the tiles. Some mold and mildew may grow under the tile, so consider using a fan or dehumidifier to help get rid of excess moisture.
● Step 2: Dry underneath the tiles
Remove the grout from between the tiles with a chisel and rubber mallet. Water under the tiles can now find its way out. Expect this process to take a while. You can use a fan and dehumidifier to speed up the process. If you manage to remove the water, clean the tiles and continue with step 5.
If this does not help remove the water from under the tiles, you have to remove them. Carefully cut them loose. This is a delicate process if you do not want to break them.
● Step 3: Thoroughly clean the floor
After removing all the moisture, clean the area with bleach to prevent mold from growing once you reset the tiles. Remember to wear gloves to protect your hands when using bleach.
● Step 4: Apply Tile Adhesive
Chip away at any previous tile adhesive before applying new adhesive, setting up new tiles, or resetting the old ones if they are not damaged. Ensure the surface is as smooth as possible before using the new adhesive and placing the tiles on the floor.
● Step 5: Apply tile grout
Wait overnight for the adhesive set before filling the spaces between the tiles with pre-mixed grout to hold the tiles in place. Then, smooth the grout lines with a damp cloth to remove excess grout and let the floor dry overnight.
How To Prevent Water Damage in Your Bathroom
Your bathroom and the kitchen are the areas where most water will be used. It means that those areas are also the ones that have the highest chance of water damage. The following tips can help prevent water damage in your bathroom:
● Inspect your plumbing regularly:
Check beneath the sink, behind the toilet, and in other parts of your bathroom for any evidence of leaks or damp build-up. Often leaks start small.
● Toilet and sink clog:
Unclog the drain if you notice that it starts to clog. I always recommend first trying to remove the blockage manually. But if that does not help, you can use a chemical drain cleaner. Be sure to follow the manufacturer’s instructions.
● Keep it clean and well ventilated:
Keep the bathroom clean and well ventilated to give mold less chance. Open your bathroom windows after a shower or bath. You can also use a fan or dehumidifier for a bathroom without a window or good ventilation.
● Repair damage as soon as you notice it:
There is a risk of water seeping into the walls and floors if the bathroom tiles are cracked, fractured, or missing. It is essential to get the tiles repaired or replaced as soon as possible. Caulking around sinks, showers, tubs, and damaged grout should also be repaired.
Frequently Asked Questions:
● Can steamy showers damage my bathroom floor and walls?
Even though steamy showers might be relaxing, the fog can penetrate your walls and cause mold. If mold starts to grow, it can swiftly spread throughout the neighboring areas. When you have a steam shower, ensure you have good ventilation. If needed, install a fan to remove excess moisture in your bathroom.
● How much does it cost to replace or repair a water-damaged floor?
Expect fixing a water-damaged floor to start at $500 to $1000. The cost will vary depending on the extent of damage and the used materials. If the damage is severe enough, the surface may need to be removed and reconstructed, raising the entire cost significantly. On the other hand, a small portion of flooring can cost as little as $500 to $700, whereas restoring floor joists in a room can cost anywhere from $2,000 to $10,000.