Customer mentioned the water problem in the basement and we walked down to look. Two floor drains just a few feet from each other. When there are heavy rains the water backs up the floor drains. This is an area where the storm and sanitary sewers are not sewerS but just a sewer, so the back up is rather unpleasant.
There is a small sump pump in the immediate vicinity of the drains, but it just can’t keep up (it just pumps the stuff out onto the street).
The city/utility know about the problem but haven’t been much help.
To me, the obvious answer is to plug the floor drains. With the sump pump right there, who needs floor drains?
Customer says that the folk from the city told her that if she plugs the floor drains the sewage would simply back up into the sinks and toilets and tubs on the first floor.
I don’t understand how it is going to back up higher than the street level. The floor drains are probably six feet below street level, so it makes sense they would back up.
But the drains upstairs are three or four feet above street level, so it seems to me the worst that would happen is perhaps air pushing the water out of the traps (and then only on a poorly vented drain).
The question is: Can she plug the floor drains??
Rich Beckman
Another day, another tool.
Replies
Lots of people in her situation have drains with integral one-way valves, or a one-way valve somewhere in the drain line.
If you install a one-way valve, or a check valve, you need to have enough head above the valve so that it will open to permit the proper flow of the waste water.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Ed using the valves is common and even required by some codes.
I was looking for something else and found this in a newsletter put out by one of the neighboring subburbs;
Backwater valves, floor drains and plumbing fixtures.
With the adoption of the 2000 Uniform Plumbing Code, we are now
enforcing the requirements for backwater valves in most houses. "Drainage piping serving fixtures which have flood level rims below the elevation of the next upstream manhole cover? shall be protected from backflow of sewage by installing an approved type backwater valve.
Fixtures above such elevation shall not discharge through the backwater valve." Please note that the plumbing code defines floor drains as fixtures and they must drain to the sanitary system.
Backwater valves must meet the IAPMO PS 38-99 standard and currently
the floor drains with the ping pong ball type backwater valve do not meet this standard and are not allowed. Please feel free to contact Steve Thompson if you have any questions or issues you would like to discuss.
I just remembered, I had seen ads for addon's for floor drains to automatically close them off.
I did a google and this is only one that I saw in about 10 pages.
http://www.keidel.com/mech/floodguard.htm
But I found a number of articles on basement flooding such as this one.
http://www.cmhc-schl.gc.ca/en/burema/gesein/abhose/abhose_077.cfm
Don't know if it'll help, but you might find this interesting if nothing else...
combined sanitary / storm sewer systems are identifiable by popping curb inlet manhole covers on the street. If it's filled with water during a dry stretch, it's a combined system. The manhole inverts have baffles on them to function like a p-trap and keep sewage gas from smelling up the manholes.
What the city people said doesn't make sense, unless the gradient of the system is such that a back-up downstream would lead to someone upstream whose invert to the main is at the same elevation as your client's fixtures. Usually building code restricts this from happening.
I would plug the floor drains. It sounds like a continous loop system with the sump.
remodeler
I would check to see if the gutters for the house run into a catch basin in the back or into the same drain system. What can happen is in an extremely heavy rain the water from the roof floods down and overwhelms the capacity of the catch basin and then finds it's way up through the floor drains.
One issue with plugging the floor drain is when the pressure builds it has to go somewhere and if it is an old house it could burst some the the clay pipes underneath. Could put in a stand pipe but they get in the way.
If the down spouts do feed into the same system I would disconnect them and have them discharge into the yard. See if that fixes the problem, sure the yard may flood but that is better then the basement. It will dry in a couple of hours.
Had that situation in our house---downspouts all fed into main sewer line for the house. Roots had clogged the line downstream and we got backups in heavy rain. Once we had the sewer line roto-rooted, problem went away, although we have to get the line cleaned every two years. We also disconnected the downspouts from the drain tiles.
Aaron
Rich,
Regardless of what makes the floor drains back up, whether sewer or rain flow, you need to stop it. IMHO one backup from the sewer line is one too many.
The low dollar quick check would be to disconnect the downspouts before the next rain storm. Others have mentioned that this might be your source.....
But a low dollar fix would be to install a back flow valve....
Open up the floor and install a backflow valve where the waste pipe goes out of the house. It allows waste to flow one way --- out. That will stop your backup from the pipes. Make sure to make to make it accessible for maintenance though.
I was required to install a back flow valve in my basement floor when I re worked my plumbing to add a full bathroom in the basement. Picked one up at HD for $25.
The sewer line in the street was at 14' down, the basement floor was maybe at 7', giving me plenty of room to argue against putting it in. The installation point ended up being directly under the basement wall. Didn't make much sense considering the elevation difference but sometimes 'a little insurance' is better than wishes afterward. Installing it was ok, but figuring out how to leave access to it once the floor and wall were closed was another matter.
Wishing you lots of fun....
MMM
Installing the back flow valve alone won't do it if the downspouts are overwhelming the system and they are on the house side of the backflow valve as mine were. Gotta do both. otherwise the overflow will back-up behind the backflow valve and come up through the floor.
Yes....You would have to do both in your case. ...
Sounds like your downspouts are connected on the inside of the house and if that is the case the heavy rain flow from the downspouts could overwhelm the capacity of your pipe before exiting through the backflow. If you plug the floor drains and backflow valve is overwhelmed your back up will show itself in the next lowest outlet. I think you might have a problem some day when Murphey visits.
In the systems I have seen at construction sites (where downspout lines are required to connect to the sewer line ) the downspouts always connect to the sewer line down-line of the inside waste line. The downspout line is connected after the waste line exits the foundation to avoid overwhelming the waste line and causing backups.
Back flow valves work when they are installed at the right point in the system. It also helps to install them in the right direction of the flow. When we were dry fitting the line my plumber friend caught my mistake. Anything I put my mind to, I could do..... given time, money, etc....
I have an old city house, They all have catch basins in the rear of the house some of the inside plubing goes into the catch basin. there is also a connection to the main line that goes under the house to the sewer, the floor drains in everyones basement also connect to their main line. The main stack goes directly to the main sewer line, but a smaller sink stacks goes to the catch basin first. At some time 75 or 90 years ago or maybe when the house was built, the downspouts were also connected into the catch basin in the rear of the house, I took them out about ten years ago and capped those lines. Someday I would like to eliminate the catch basin but right now is it not hurting anything and it would be pretty expensive to dig everything up. That is the way everyones house is in my area. No sump pumps here unless they had an addition put on with a full basement.
If the original posters set up is similar, I would bet dollars to peanuts that diverting the downspouts would solve the problem. But if it is really the sewers backing the check valve would solve it as well along with everyone on the block taking the down spouts out of the sewer system. The city here is trying to get people to do just that.
Thanks for the info everyone. Sounds like plugging the drains might be OK. Though I'm not excited about the comments on the lines buckling under the pressure.
Bill, thanks for the links. That Flood Guard device seems to be just what she's looking for.
I checked the gutters (I've been reading Breaktime a long time!). They drain to the yard. I pointed out to her that one of them could stand to have an extension on it.
She does also get ground water up through the floor occasionally, but not in the same quantities as when the sewer backs up (and the groundwater isn't nearly as offensive).
The drains backing up is almost an ordianary experience for her. Everything in the basement is up on blocks. When it happens, and the sump is pumping it back to the street she adds bleach (!?!?) so it won't smell so much. As soon as it' all gone she washes and bleaches the floor.
It didn't smell bad down there at all and it had been flooded just two days before!
Rich Beckman
Another day, another tool.
Rich,
Do you think it is possible that your client is hooked up on a Y connection with a neighbour to the city line?
If the neighbour is at a higher elevation, a block in the line past the intersection could be the reason for the backups into the basement. If the neighbour's gutters are tied to the sewer line rather than draining to their yard as well, this may also explain the rainwater back-ups.
Plugging the floor drains could still lead to backups higher in the system if the backflow valve is not installed.
Cheers,
Paul.