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Not another basement water "management" thread!

2484 Views 11 Replies 5 Participants Last post by  WillK
Have not been able to reliably dry the basement in 22 years. The basement needs to be dry. So I have started an interior perimeter drain.

Yeah, there are things that need to be done outside, but they have never been reliable before. No reason to believe outside work alone would work in the future (that definition of insanity thingy) so I'm doing the inside first because the basement needs to be habitable and the outside stuff will be done later.

The house is poorly located on the lot. It sits only a foot above the lowest point in the yard with most of the yard higher. The low side of the yard is on the side that only has three feet to the property line and pushing water away from that side just puts it in my neighbor's basement. I suspect he might have issues with that. There are big concrete steps on the front, paved driveway and carport on one side, concrete patio and basement steps on the back and three feet of property on the other side. Digging six-seven feet down to the footing outside is not going to happen.

The starting point is the sump I put in 20+ years ago. So far I've gotten about 20-25 feet dug out of 120 total planned. Since we measure droughts in hours this year, the trenches have already been tested and I'm comfortable that this path may actually work. The trench might be bigger, but I am intentionally keeping it smaller to reduce the stuff that has to be hauled out and material that has to be dragged in. The trench is lined with landscaping cloth in addition to the sock around the drain pipe to reduce silting of the trench itself because I noticed that the gravel bed around the sump has silted up solid.

Question: What is a cheap way to get water from behind the water proof membrane on the wall into the drain tile under the floor? Cheap is the operative word. Dimple membrane would be nice, but my heart (and money... but mostly my money) belongs to others. So I'm thinking 1) 6 mil sheet hung from the wall, 2)... 3) water goes into drain tile. Then build a frame wall over the sheet.

Second item: I've seen a number of posts about building a 4" frame wall offset 4" from the concrete foundation wall. That sounds like a lot and I don't want to do all this and end up with a basement closet. Old walls in my basement have aged badly because of the persistent water issues. So my plan was to use all treated lumber, ROXUL mineral wool insulation, blue board and maybe even cement fiberboard for the lower foot or two of the wall because I have to assume that no matter what I do, it will get wet again. Note that the planned use is utilitarian, not finely decorated.
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Everything I do on this 83 year old house turns into an voyage of discovery. This weekends discovery is that about three inches inside the footer is a massive lump of concrete, running about six inches thick. At first I thought it was a second footer. Like they had poured one but realized the house was supposed to be bigger so they poured the second. Probably it is excess concrete scraped off and left in place. If the drain tile was run along the top of the footers there would be only two inches between the top of the drain tile and the floor. A little thin. I considered digging down to full depth between the castings and just putting in gravel wrapped in the landscaping cloth sleeve. Also thought about renting a jackhammer but am afraid how much it will break up the floor nearby by pounding on this layer underneath. Don't want to have to relay the entire floor. So for now, it's hammer drill and hammer time. And slow going.
Can you post some pictures?

The pipe should not be wrapped directly with landscaping cloth. There should be coarse material in between to keep the cloth from clinging to the pipe and reducing the square inches of cloth through which water will actually soak through and get into the pipe.

You will have to either crack up and remove the excess concrete blobs or set the pipe further in from the foundation wall.

If the pipe is a foot in (wholly, not on centers) from the normal edge of the footing then the trench bottom can be three or four inches below the bottom surface of the footing which will improve the performance a little. IF the pipe is right up against the footing then the trench bottom cannot be any lower than the bottom surface of the footing.
The drain tile is the black corrugated HDPE that comes pre-wrapped in filter cloth. Even the holes in the drain tile itself are little more than slits which probably provides another layer of filtering. The landscaping cloth is lining the trench to reduce silting of the gravel bed. That makes three filters between the clay slime at the bottom of the trench and the inside of the pipe. So the pipe should start silting up in 3...2...1...

The sump pump is in the Big Dungeon (former coal cellar) under the front porch. The pipe had to pass over the footing as it went through the door to the main basement. I gnawed through about 4 inches of the footing, but didn't want cut all the way through it so the trench depth is fixed at about 10". This doesn't make it to the bottom of the footing. The top of the footing is around 6"-8" under the floor and the sanitary sewer drain is fairly low in the floor, which makes me think that at some point somebody was thinking of putting in a 7' ceiling, but ended up with a 6'8" ceiling. I have not dug down to the bottom of the footings anywhere, even out of curiousity.

Had another adventure in home remodeling Sunday. I had the kids move dirt out of the basement. My wife suggested they put it behind the house where we are going to regrade to get water away from the house. I said the side of the stairwell needed to be raised first. The dirt ended up piled up against the house. Sunday we had a monster rainstorm (because it had only been a few days since the last one). Fortunately we were working downstairs as Niagara Falls came over the top of the stairwell wall and rapidly began flooding the basement. So in the rain, thunder and lightning I had to dig the dirt away from the house to redirect the river. Moral of story: water flows downhill. Know where downhill is. And don't let the wife tell you otherwise.
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Sewer overflow question

Perimeter drain progressing at better than my usual glacial pace. Wife is getting excited at being able to put something down on the floor besides despair. And so the house has responded with sewer issues, which has always been a chronic problem. Have had backups and snaked the sewer twice in three weeks. I'm actually contemplating having a plumber run the sewer with a camera to see what's going on.

So question 1: What happens if a sewer backs up and overflows into a perimeter drain system? Is it written off as a force majeure when it's pumped onto the yard from the sump?

Question 2: can an overflow to the perimeter drain be put in intentionally to prevent backups from running across the floor? The floor drain now is in a fairly deep depression that is difficult to walk across. I have been thinking about extending the floor drain up and creating a shallower depression ('cuz I'm getting lots of practice pouring concrete) But the current depression acts as a catch basin and gives us some warning when the sewer acts up. A raised drain would not provide that cushion. So I was thinking of tapping off the riser to the perimeter drain. Instead of the sewer overflowing on the floor, ruining my wife's floor aspirations and then running out the perimeter drain; it would just overflow direct to the perimeter drain. It would need a high water alarm or we wouldn't know the sewer had stopped until the yard began to stink.
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First post was late June. Finished 15 Dec. About 6 months (that's about my normal pace). 130 feet of trench with drain pipe. 3ish tons of gravel. Over 2 tons of Quickrete. Added two drains to two window wells (they didn't have drains originally). Added trench drain in front of door threshold in basement external stairwell (this was the motivation for the complete perimeter drain). Replaced basement door with steel door (threshold of door unit needed to be set in concrete which was done in combo with the trench drain. No more water will enter under the door. Ever.

We've had a number of big rains recently with no signs of leakage. Spring should provide the real test.
Sounds like you work around the house like I do!!
The sewer should not be connected to the perimeter drain in any way. The only possible way for sewage to get into the perimeter drain system would then be if a toilet overflowed onto the floor.

In that event much as possible should be removed by other means because the sump pump is not meant to handle solid material. But imanual cleanup does not have to be so perfect that no sewage ends up where the sump pump normally pumps water.

If you are concerned about sewage backup, put a check valve intended for that purpose in the sewer line.
Separation is what I went with. Check valve in sewer won't work because source is the house itself, not street backing up. I'm at the top of a hill. If sewer backs up to my house, people at the bottom of the hill will be sleeping in SCUBA gear. My issues are tree roots (80 ft sweetgum sitting on sewer. Speaking of which, I was amazed at the amount of tree roots under the house) and a house trap at the street that likes to gunk up.

Sump pump stopped after a weekend of heavy rain. Basement was flooding from every crack and pore. Turned out the plug was not connecting well in the socket. Moved the plug to the other socket and the pump started up again. Water flow through basement ended like someone had turned off a faucet. Perimeter drain has been working as well as I had hoped. Unfortunately it failed like I expected it to. I am now dependent on a functioning pump whether there's power or not.

I want to put in a water powered back up pump but the house suffers from limited water pressure and flow which makes a venturi pump problematic. I have a plan to replace the water service which will take care of flow rate, but I'm at the top of a hill right next to the water reservoir tanks. I'll never get real good water pressure.

Does anyone know of a water powered pump that is positive displacement (diaphram, piston, etc) vs. venturi? It would be functional based on available static pressure even of the flow rate is low.
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the plan for a wtr-power'd backup pump sounds good - zoeller is the only mfg that has 1 to my knowledge,,, we routinely wtrproof homes but have no experience in wtr-power'd b/u's as our practice is now limited to commercial & condominiums,,, will be interested to see if your last post gets more replies/answers - good luck !
My parents house has a basement which is below the water table, their sump pump runs very frequently, and they've had a number of basement floods when the sump pump has failed or when there have been power outages. The water powered backup they've added has worked very well to take over when there is a failure or power outage.
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