Signs of a Hidden Water Leak in Your Bathroom

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Subject: Water in basement

We bought an older house that was completely gutted. The basement is finished with drywall and we were told by the seller that they never got water seepage. Two weeks after we moved in we had a stormed and got water seepage and had to remove baseboards and carpet. Three weeks later we had another issue of seepage. The other day I discovered plastic under a small part of the carpet... Is this a sign that they had prior damage?


Subject: Orange/rust colored circles on the kitchen floor

These circles are all over the linoleum in our kitchen, and there gets to be more of them. We don't have any plumbing leaks that we know of. They aren't from the chairs or table. They seem to be in line with one another, like where nails/screws are under the floor?


Subject: possible leak?

I have recently noticed the carpet outside my shower dampening after showers but can't get under the house to check the pipes. Where would I even start to troubleshoot doe a leaky pipe?

Kaye Milton

Subject: Mushrooms on my baseboard

HI, we have mushrooms growing on a baseboard under the sink cabinet which is next to the shower. Could that be a leak or just moisture from the shower? They are growing through the baseboard.


Subject: Confused as to what is going on.

My husband and I bought a house 2 years ago and everything seemsed to be going well until now when our ac unit went out. We had to buy portable window units and its so hot in our house it's caused mold to grow really bad in our Kids closet (they don't use only) the light sockets started to drip and peel up at the corners. I thought it was a water leak as our shower is on the other side of the wall by their closet but then their paint started peeling and cracking. Last night I went to move the crib. My back against the outer closet wall. And it caved in as if Id been thrown into it and I barely used any force. None of this started happening until we got the portable ac unit in that room and this house. But it doesn't do this in our room. And our room stays the hottest of every other room in the house and it's fine. Please tell me how to fix this and If you know of anything that works well against mold on walls and doors. I've been using soap, water, bleach, vinager I found it online. It works okay with my scrub brush. I just want to make sure it's absolutely clean as its my kids room. They aren't in there now, not until we figure this out. But I need to get this solved fast.


Subject: Water Leak in mobile home

I live in a mobile home, and ive noticed water seeps thru the tile in my bathroom when i have been stepping on it, and recently water has been leaking from under the bathtub and sink onto the floor. Does anyone have any idea about what it could be, or how much it will cost to fix?


Subject: I had a similar problem and

I had a similar problem and found that the grouts between wall tile weared out. The bottom layer of tiles just came out on touch . Removed the tiles and found that the wood board (yes not cement board) behind it, is completely soggy. Removed the board, attached a cement board, one coat of RedGard and then retiled and grouted. All problem solved.

Phyllis D

Subject: Water Leak in your mobile home

I learned that grout between the tiles needs to be renewed or sealed or water can seep behind the tiles into the walls and in your case, the floor. There is a product called Grout Boost that is best used when installing the tile I guess. I don't know if this is your problem, but if it isn't a plumbing problem or a leak elsewhere, the grout might be the problem. A plumber might be able to help diagnose the problem. Just sharing what I learned. Also you might have a claim with your insurance company.


Subject: Leaky shower seat

I just completed a year in my brand new house on Friday. On thursday we realized that the carpet right outside the master bathroom in the master bedroom was soaking wet. We called in our builder who sent a plumber out. The plumber let us know that we had a severe leak due to whoever built my bench seat in my shower not laying in flush against the tile. This in turn left a large hole the size of two fingers across under the seat which he then tried to put caulking in to hold. Well the caulking fell off and it has been leaking for a long time now. It has caused major damage and I have no idea where to go from here. We would have never thought to look for a hole under the seat.


Subject: Leak in ceiling where there is no pipe?

We have a soft and damp water spot in the ceiling in our garage. It's about 2ft in from the outside wall and the size of a baseball. The master bedroom is directly above it (the bed to be exact). There would be no reason for a water pipe to be there, or within 7 feet of there. Any idea how this would happen? The only other thing close by is an air register in the master bedroom. Thanks!

James Figy
James Figy

Subject: Mystery leak

That sounds like quite a conundrum, AK. And it's hard to diagnose without an in-person examination. As the article notes, "because water can travel a long distance, it's possible to find water stains on the ceiling farther away." The only other possibility I can picture is: Could the cold air in the register and the warm air from the garage create enough condensation to make the water spot? It might be time to call a pro to cut it open, fix the problem, and then patch the drywall. Good luck! -James F., staff writer for Angie's List Magazine

Gary Kaufman

Subject: Water Damage

I see water stains on my walls in two bathrooms that are back to back, where the wall meets the trim at the floor. The stains seem to be on the walls that would share a common space between the bathrooms. What type of a professional do I call first, a plumber or a general contractor?

Jeffery Hayes

Subject: Water Damage

I'm assuming you already got this fixed but I'd go with a Plummer as they would be able to fix both where a General Contractor might, but they might have to get a plummer to do the pipes and then them do the walls. Best bet is to call a Plummer first as they should be able to do both.

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First - NOT full septic tank - if that was the case you would be getting backup of sewage into the lowest drains in the house, and possible very slow flushing or refusal to drain out of the bowl - the opposite of your case.

Second - I assume you are the owner. If a renter or on a lease, this type of problem may be the responsibility of your landlord, depending on the terms of your lease or rental agreement.

OK - two possible situations here - low water in BOWL, or low water in TANK. I am assuming your toilet flushes OK, with adequate water to clean out the bowl, and that it is a typical type toilet with a tank sitting on the back of the bowl. If this is not the case and it is a designer toilet or looks like those at public restrooms (no tank), then the BOWL answers still apply if it is initially refilling OK, but if not enough refill water coming in at all then call a plumber.

First, low water in the toilet BOWL case. If the water in the toilet BOWL is low after flushing, I see four likely causes, in order of most likelihood -

1) the fill valve is not putting enough water into the toilet bowl. If you take the top off the tank, you will see a small hose (typically black plastic) coming from the fill valve (a vertical mechanism, usually at left side of tank, that the incoming water tube or flex hose connects to the bottom of on the bottom side of the tank). While the tank is refilling after a flush, a steady but not large flow of water flows through this fill tube and down into a vertical pipe or tube (usually brass or plastic and about 3/4 inch diameter, which stands almost full height of tank). The small tube puts water into this pipe, from where it flows into and refills the toilet bowl. This is also the overflow tube, which keeps the tank from overflowing if the fill valve fails to shut off. If the fill valve has a problem or the fill tube has a blockage, it may not be letting enough water into the bowl. Also, check the tube is actually pointed down into the overflow tube - if the clip came loose, rusted away or broke, then it may just be filling the toilet tank rather than the bowl. Check that a steady flow (will not be a real foreceful jet) of water is flowing out of this tube into the overflow pipe while the toilet tank is refilling. You should also see the bowl filling up at this time. If it come in but does not fill high enough because it does not run long enough, some fill valves have an adjustment - check fill valve manufacturer website for instructions. Others just have to be replaced - doable if you are handy at home repairs (see web videos on how to do it), or call a plumber for probably about $150-200 to replace fill valve (have him replace the flapper valve at same time if you get this done).

2) there is something like a rag or string caught in the trap (the waste passage within the toilet body itself) which is slowly wicking the bowl water down the drain - would be solved by a good snaking. If this is the case, the bowl will fill fully after flushing, but then slowly (typically many minutes to hours) drain down to just filling the start of the oval or round drain passageway where the waste passage starts to curve up into the toilet body.

3) blocked sewer vent pipe (which vents sewer gas and lets air into the sewer system so when you flush the traps in drains and toilets and such do not get sucked dry by the vacumn caused by the exiting flow. If this is the problem, then several drains in your house may have the same problem, or drain slowly. When you flush, the water will drain totally down the pipe and almost all the water in the bowl and trap will go down the drain too, typically with a gurgling sound for a few seconds at the end as the air seal is broken in the trap, then a small amount of water will flow back from the trap into the bowl, leaving you with water in the entrance curve to the trap but nowhere near normal height in the bowl - maybe not even enough to fill the entrance of the drain passage.

4) a crack in the toilet, letting water gradually leak out of the bowl onto the floor or into the subfloor. If this has been going on for long at all you should see water on the floor, or water coming out in the ceiling downstairs, or in the basement or crawl space under the toilet.

Case 2 - the problem is low water in the toilet TANK - since this is a sudden problem, two likely causes:

1)  the float arm has corroded or the float setting has moved. Look in tank for any broken part. You may have a black ball on the end of a metal or plastic arm connected to the fill valve (which is the part, normally at the left side of the tank, that the flexible or copper tubing comes into at the bottom of the tank), or it may be a sliding cylindrical float that slides up and down on the fill valve (typically all plastic) - see if it is broken or loose or alll corroded up (for the arm type). When you flush, this float hangs down (if lever type) or slides down the fill valve (cylinder type), opening the fill valve so fresh water comes in to fill the tank and bowl. As the tank fills it lifts this float, till at the proper elevation the bouyancy of the float shuts off the fill valve. If the setting on this float has changed then it will either cause the toilet to "run" continually because it is trying to overfill the tank (float shuts off at too high a level, so water is continuously flowing down into the overflow tube and into the bowl); or it will shut off too soon, causing only a partial tank fill. There are adjustments to adjust the float shutoff setting - typically an adjustment xxxx on the arm-type, and a slider stop clip on a small rod for the sliding type. See web videos on how to adjust this, or call a plumber.

2) your flapper valve (in bottom of tank, the part a chain or cord or rod connects to the flush handle, which opens it when you flush the toilet, leaks. If it leaks AND the fill valve is working, the tank level drops till the fill valve opens, then the tank refills. This repeats at intervals, with the tank refilling periodically even though it has not been flushed. May need new flapper valve or just a good wiping of the sealing surface to remove grit that is causin it to leak. If this is the problem you will have a slight flow of water into the bowl continually, and will probably see a slight ripple in the toilet bowl.

3) water is leaking out of the fittings or bolt holes on the bottom of the tank. If this is happening enough to make you notice low takn water level, the tank will refill periodically the same as if the flapper valve is leaking, plus you will have water on the floor and dripping off the bottom of the tank.


Fill valve and flapper valves each cost around $15 if you do it yourself (you can buy just replacement flapper for less if that is the problem and the matching seal is good, but that is rarely the case). A plumber call to replace both probably $150-200, ASSUMING your water shutoff valve (at the wall, under the tank, with a flex or copper tube coming fromit up to the toilet tank) will work.. If it will not shut off the flow of water, then add another $50-150 to replace that, depending on how it is plumbed and whether he has to cut into the wall to replace it (rarely required). If you do go and have a plumber do it, have both the fill valve and flapper valve (and flush handle, if aluminum or brass and corroded) replaced at the same time, as all tend to go out with age - every 10 years or so. You don't want to have to call the plumber to replace another part in just a year or two.


From the sounds of it, you have a clog between the floor drain and the connection to the city sewer (unless you have a septic tank).  The lower flow rates of sinks / showers / dishwashers probable don't cause a backup like the washing machine does.  A couple of suggestions.

1.  Snake the drain line with a spade tip snake, twisting the snake as you advance it.  This should clear the partial blockage.

 2.  If feasable, have your washing machine discharge into a utility sink and put a strainer on the drain to catch the clothing fibre (fibres and grease from the sink probably made the clog in the first place not to mention a garbage disposal).

3.  Replace your floor drain with one that has a backflow preventer (looks like there is a ping pong ball in it).

 Good Luck

It is not uncommon for a plumber to have to go get the parts necessary to repair and complete the job.  It is very hard to determine what the problem is over the phone and it is not until the repair process begins that the parts needed to resolve the problem is discovered.  It may also depend on if the plumber is using hourly rates or per job rates.  I would hope the time to get the parts would be minimal and the charge would be as well!

You have not said how old your house is, what normal water line life in your area is, whether it is leaking under the foundation or under the yard, etc. Cost depends a great deal on length of run, depth to dig to get below frost line, whether excavation will be through trees or other obstructions or open area, whether ground along route is too steep for a backhoe to work on, etc.

The first thing you really need to figure out is whether this is a spot repair issue, or a total line replacement issue. Your plumber should be able to help with that determination.  Very general rule of thumb - very old line from before 80's, if galvanized pipe, could be at its practical life and be ready for total replacement. Copper line generally last about 50-70 years UNLESS in a corrosive soil environment or if it has groundwater flowing actively past it, then can be 20-30 years. Plastic lines from the 60's to 80's vary a lot - from as little as 10 years to 50 plus dependingon brand. Plastic lines (PVC, HDPE, PE) from the 80's and later are expected to last 50-100 years - most have not failed yet, so no good handle on how long they will last.

An above-ground or under the slab line a plumber will do. Buried line outside he generally subcontracts to an excavator to dig and backfill the line, or asks you to get the excavation done.


If section needing replacement is under your floor slab or foundation, then a full replacement can be many thousands of $ depending on how many linear feet, and if interior flooring will have to be replaced or if you are on a bare concrete slab or bringing the new line in above-ground once you get through the foundation. A simple one-spot buried pipe repair (based on acoustic locating and precisely measuring the location of the problem) can be as little as $400 but probably more often $1000 or so - more if poor access like under a slab underneath stairs.

If the runs to be replaced are exposed in a crawl space or basement than it can run as little as $20/LF (probably $400 minimum job cost) to replace.


Outside line to the street can run from as little as $10/LF in areas where the pipe is shallow (no annual frost penetration) and in easy digging soil, to $250/LF or more if deeply buried, have to excavate through trees and heavy roots or boulders, steep topography, other utility interferences etc. Generally not more than $50/LF. Commonly, instead of digging up the old line, they select a new semi-parallel route from a good connection point for you existing interior water lines at the foundation (maybe not where it currently comes in, depoending on access) to the street main shutoff valve (called a "key box", taking a route between them that is easiest to get a backhoe into and minimizes destruction of valuable plantings or trees. A number of $50/LF is commonly tossed around as "normal" for this type of job, if exceeding 100 feet or so and digging and access conditions are normal.

If your connection is in the middle of the street rather than along your side in the yard, that can easily add $2-5,000 to the job, as the water utility usually has to do that part, and repair the street afterwards. In a major throughway street, even more because of traffic control, multi-agency permits, etc.


As always, find 2-3 responsible, well-recommended (Anglie's List ?) contractors, and then get bids. The route I would go is first go with your regular plumber to locate the leak (probably acoustically, by listening for the leak) and determine the scope of work needed, then if major, go for multiple bids.