Okay, here's a head scratchier for you.

My sister-in-law called late yesterday afternoon to ask for help cleaning up yet another water spill in her downstairs hall.

As you enter the town house, there is a stairway to your immediate left. At the top of the stairs is the dryer/ washer.

As you look straight ahead apx. 15' of the left under the dryer / washer is a small 1/2 bath. Periodically (about every 6 to 8 months) water floods the bathroom floor and migrate out into the hall . No one can find a leak on the current flood.

The vanity, which is directly under the dryer/washer is bone dry and the water to the vanity do not feel like any water is spilling from the fittings. The stub out to the toilet however feels very cold and has condensation on it. None of the walls are damp, nor are there any water markings on the ceiling to indicate the spill was coming from up stairs.

When the house was built, the builder used some type of piping that is now outlawed. Apparently there was a settlement and home owners were give money to replace the piping. The original home owners pocketed the money but did not make the repairs. When my sister in law purchased the house, she was not told about the bad pipe. During one of the flood, a plumber discovered a leak on the outside wall of the 1/2 bath and it cost almost 1500 dollars for the plumber to remove the old piping and replace it with new stuff.

Since that time, we have replaced the wax seal on the toilet twice and finally the entire toilet and fixtures. Yet the leak occurred yesterday.

The only thing odd yesterday is that my sister-in-law said she did two back to back loads of wash before she left the house for two hours. When she got back, there was the flood and some guy named Noah looking for a place to tie up. :)

Is it possible that the washer is the source of the leak and water is running down the piping to the 1/2 bath and finding it's way out from under the vanity without wetting the walls?

How is her washer drained, into a stand pipe in a wall? How large is the drain pipe 1.5 or 2" ? Has she ever noticed that the floods only happen around wash day?

No, those were some of the questions I asked her, though. Discharged water goes from a hose to a 1.5 inch stand up pipe, mounted in the same area as the spigots.

Now that you have me thinking about it, while I did not see the actual spill in the bathroom, I thought that I was pulling up a lot of dirt from her carpet. I just put it down to high foot traffic.

Not gray water, but dark mud brown.

We got it last evening.

While we were over at my Sister-In-Laws place for dinner, I had my son open the clean out and then she ran another load of wash. Bingo, the small amt of "Standing" water immediately flowed up the clean-out and onto the yard. The downstairs toilet bubbled like crazy, but it did not spill over, because the clean-out was now open.

Today I took a flat steel plumbers snake and found the clog about1- ft. past the drain clean-out towards the sewer line. It took a while but I was finally able to clear the blockage and then tested with a water hose.

So the net of this one was the water in the drain pipe would back up and water finds it's easiest path backed up into the toilet and over the bowl, viola, one flooded bathroom and hallway.

Good plumbing work Don. That brown mud wasn't mud was it. I was thinking it might have backed up the stand pipe or be the washer water backing up. By the way, that stand pipe should be 2" especially if she has a newer machine. The 2009 code will require 3" pipe on new installations.

It sure looked like mud. It certainly did not carry the odor of human waste. And believe me I know that odor. Our septic tank occasionally had problems when it filled after very heavy rains.