My Idea for Fixing Water Intrusion in Basement. Thoughts?
I’ve read all the “flood in basement” posts in the Forum for awhile and, having experienced many cellar floods myself, have put some time into a system that I think will address my problem BUT I want to hear what the Bstoner community thinks of it. I have a 20×45 roof and a cellar with…
I’ve read all the “flood in basement” posts in the Forum for awhile and, having experienced many cellar floods myself, have put some time into a system that I think will address my problem BUT I want to hear what the Bstoner community thinks of it.
I have a 20×45 roof and a cellar with a main house sewer/drain line BELOW the cellar slab.
Simple system: 1) Install check valve on main house sewer/drain line and 2) install professional grade large capacity dry well under rear yard and route roof drains, downspouts and rear patio drain into it.
This does two things: 1) protects from inevitable backflow when the sewer overflows into my cellar (pops off the cap on the “U-pipe” in the sump hole and 2) when check valve is activated, the roof and rear yard drainage have someplace to go.
If I just installed the check valve, the sewer water would stay out but the roof water would still flood the cellar. This keep sewer water AND roof water out. Single family home, so no problems with tenants running dishwashers, washing machines showers, etc. when the check valve is activated.
What do you think of the systems design and what are your cost estimates?
Thanks in advice for all helpful/positive/non-flame comments.
You have some good ideas. I found a good resource at http://www.b-dry.com/wet-basement-solutions.html All the best!
The frost line in the NE is 30″. So you would need to start your DW and the perforated pipe below that level in order to avoid having it freeze and subsequently flood the surrounding area.
Also consider the idea that you will need a permit, and the requisite engineering/test borings filed with the city, in order to install said DW.
For the poster who claims that roof run-off does not evacuate through the house trap – where does it go otherwise? My house has only one trap and everything, including the roof leader, runs through the trap to the sewer main.
stonefill should just be the base of your drywell, the actual well would have to be an inverted concrete form. this would have to be large enough to accomodate the expected rainfall, and then you might need a pump system and second cistern to release overflow into city sewer under gravity pressure
I don’t have the chops to assess your plan, but a word of warning on check valves: Don’t go to sleep on the maintenance. Ours protected us for three years (we have a bathroom below grade that floods in backflow situations), but failed in the July and August floods. The problem: The valve got stuck in the “open” position, leaving us unprotected.
It had been checked last spring, so obviously 15 months is too long to let it go. Now I’m opening the hatch every so often to figure out how often it needs maintenance to keep the hinge from freezing.
Maybe this is obvious, but if it helps anyone from getting flooded, I figured it was worth it.
The city does not allow roof runoff to go into the sewer, not the other way around as traditionalmod suggests. The reason for this is that if everyone diverted their roof runoff into the sewer, the sewers will overflow causing sewage to flow directly into the east river, ny harbor etc., which already happens in heavy rain fall.
When I figure out how to post a picture here I’ll show you what you need to do.
Don’t do what you drew there. The other poster is right. You can’t make a drywell big enough to hold the water from the roof. And if you could, it would mean as much work and expense as doing something better and more reliable.
Don’t put your roof drainoff in your drywell. Roofs get literally hundreds of gallons of water coming off them, in a rainstorm. They calculate exactly how much with a per square foot method; you can find the numbers if you google research for rain barrels.
I would suggest this:
* Definitely have a drywell for yard and patio runoff. We did, and it took care of that issue for us (knock on wood).
* Install (professionally by a landscape architect who knows how) rain barrels to capture roof runoff, and there’s a switch on the gutter pipe that sends the rest of the runoff down into the sewer when the barrels get full. NYC doesn’t allow you to send runoff from the roof into the yard, so you’ll need something that is hooked into the sewer. That way you reduce how much water is going down your sewer, and you can use the runoff water in the barrels to water your yard and plants, and to wash off your patio and deck.
It’s a good idea, I tried something like this on my house. However, my main problem with my basement flooding was when the water table gets really high the ground can’t take anymore water so it would push through my back wall. Your dry well well help a bit but when a hard rain falls, it’s still in your yard. I found adding additional drains to the sewer and out to the street worked best at moving the water as fast as possible. Just my experience.