Do you test floor drains?

I received a call from a client who I did an inspection for back in February. They had water coming up through the floor drain in the laundry room that flooded a portion of the first floor. Plumber came out and rodded to the street and when that didn’t work, rodded the drain inside the house and this cleared the clog.

They weren’t looking to blame me for anything (Thank God for spending the time to explain the limitations of an inspection!) and were just looking for advice, but it got me to thinking that maybe I’d be doing a better job for my client if I started running water down these to test for drainage.

Do any of you check this and if so, how?


When people are moving many just take left over cereal ,flour, salt,cofee, macaroni and many other things including fish tank gravel down the drain.
You can not be responsible for what happens after the inspection.

… Cookie

To test them properly one would need a hose or some other method to run a lot of water to be sure. No, I don’t typically test them and note it in the report and verbally, if the client is present.

With all the rain we’ve been having, It’s not suprising that they’ve backed up. I’m sure many of their neighbors have as well.
If you “tested” a floor drain by running water into it and it did back up, the sellers would probably stick you with a bill for the plumber + damages caused by the water. If it ran clear, there’s no way to predict what three days of thunderstorms (or macaroni, or fish tank gravel, etc) will do to it. If it is a problem whenever it rains a video inspection would let you see if there’s any problem in the drain itself. if it is a design (or load) problem and the city sewer is backing up a backwater valve can be installed outside.

Another favorite item people “flush” down the toilet is used kitty litter. Thats right, the kind that clumps when it gets wet. Once it gets down the drain just a short way it turns to concrete. The taletell signs are traces of the litter in the bottom of the hopper that have solidified. It is everyone’s right to be stupid, some just abuse the privilege. As stated, when people move out, they empty the freezer, the fridge and dump everything down the garbage disposal (which is not designed for that kind of usage, one would need a restaurant style disposal), then throw all those dirty containers into the dishwasher, which drains into the garbare disposal too, completely overwhelming the system, resulting in clogged drains and you get the call when the folks move in and find the problem. I explain this process to everyone I do an inspection for if there is a garbage disposal at the kitchen sink, especially one that is old and anemic and can barely puree an ice cube. Educate your customers!!!

A related question - do you ever recommend installing a floor drain when you inspect rooms where a plugged toilet or other serious leak would do a lot of damage to the area or the floors below?

That would include every upstairs bathroom, laundry, and equipment room. The answer is no. There is no requirement for it, so why should I recommend one? The cost of plumbing an existing house this way would be prohibitive.

All my reports say this: “Because of the damage that could result to flooring systems from “destructive testing” for which we could be held liable, we do not test the overflow drains for bathtubs, shower pans or floor drains.”

If they’re in a place where they may not have had any water down them in a while, I tell the client how the trap works and explain what happens when all the water evaporates. Don’t test them though.

In some houses around here the floor drains are not connected to the sanitary system but drain directly outside instead. The theory is that if the sanitary system is plugged up hainv a floor drained into it would not be of much help. Probably not allowed in some jurisdictions, but a very effective and sfafe installation, IMHO, given the rare ocassions of use.

If I have an accessible water supply ie laundry tub, hose bib off water supply line, washer hose bib ect. I test the drain. I bring a set of adapters I picked up at a local hardware store which allows me to attach a hose to just about any faucet. I also made an approximately 15’ hose that I bring to my inspections. While inspecting the furnace and water heater I attach the hose and run water into the drain at a moderate flow for at least five minutes. By then it should have reached the street sewer and I will know if there are any blockages. If it’s running smoothly I increase the flow. Obviously I never leave the room and always keep an eye (and ear) on the drain. I have been doing this for the past five years or so ever since a competitor got sued for not testing a drain and the clients drain backing up the next week! If the drain or a water supply is not available I notate that in my report. You should have in your pre-inspection agreement a section that specifically excludes concealed or latent defects from the inspection to cover yourself should the seller due the cat litter thing after you leave.