Interior French / Perimeter Drain on 1890s 3 flat with Stone Foundation

[samneal7]

With all the political talk on here- I am not sure if it is still a home repair group- but I figure I'll give it a shot. I am currently digging out my basement and installing a french drain/perimeter drain system next to my footings. My building was built in 1890 so it is built on a stone foundation (accept the footings which are concrete). Most advice/direction on perimeter drains are for newer homes with concrete foundations or slabs. Does anyone here have experience with a stone foundation? My footing is about 18 inches below my basement floor. Is it best to lay my pipe next to the footing or on top of the footing? Either way it is still well below the floor. How many drill holes should I drill through the foundation to make weep holes? Would one every 12-18 inches suffice? Where is it best to drill the holes- can I do it just above the footing where it is a bit thinner? The walls are very thick- 18-24 inches thick and the footings are even thicker. Any advice is appreciated, thanks.

[hubops]

Hard to imagine _why_ you're doing this ? Perhaps I'm not understanding the french drain concept ? Did you consider a sump pit & sump pump - with an above-grade outlet - which runs away from the foundation ? John T.

[S N]

French / perimeter drains capture water that weeps in from your walls and from hydrostatic pressure caused by changes in ground water levels that push water below your basement floor. If these drains are installed correctly, they reduce the pressure and lower the water table, resulting in a dry- usable basement. The best way to do these is to install them outside your home- unfortunately, I am in a dense city where our buildings are basically lot line to lot line. So I have to dig it inside. The drains all slope towards a sump pit with an above grade outlet.

[hubops]

OK - but it seems like you are inviting more water into your cellar if you create new holes through the footing/foundation - and therefore asking for a busier sump pump .. ? John T.

[S N]

Yes- that is the right way to do it- you don't want water pooling around your foundation- it can cause spalling of your brick and concrete as it soaks in and up. It can also lead to mold and other issues. Its best to have it dry around your foundation. I understand if you have never dealt with them it may seem odd to do but its the only way to reduce exterior hydrostatic pressue without installing a perimeter drain on the outside.

[hubops]

OK - thanks for the explanation.

If it was me - I would try to reduce the "hydro-static pressure " ? from the outside - before inviting it inside. .. landscape swales ; downspout helpers ; neighbour's drainage ; etc.

I feel sure that you have already done that research.

Good luck.

John T.

[TimR]

I'm not an expert and I'm doing some of the same research on my house.

In my case it's clearly not ground water pressure, it's heavy rains that don't move far enough from the house. I'm redoing my gutter and piping systems soon.

If your basement is really down in the ground water table, I think you're on the right track with a french drain and sump pump.

There are a couple of other options. My church installed B-Dry successfully. I don't know the details, but they put in trenches and a false wall, I think. It moves the water outside. Another option is electro-osmotic.

Okay, it sounds like fake science, but I've talked to military engineers who've used it successfully.

[trader_4]

No information on what the current situation is or any problems. Is the basement dry, mostly dry, some water is a few spots after heavy rains or Lake Michigan?

Whether pipe is on top of the footing or next to it would seem to be irrelevant. The pipe is surrounded with crushed stone or washed gravel, water will flow. Not sure how you could put it on top of the footing anyway, with that having the stone foundation on top of it. Absent some unusual problem, drilling holes in the footers sounds like overkill.

[trader_4]

A sump pump just stuck in a hole will remove water in the small area directly around it. It's not going to do anything for water thirty feet away, at the other end of the basement. That's why perforated pipe is run around the perimeter during construction that leads to the sump pit. The OP is going to add this a bit later.

[S N]

Hi Trader, The situation is complicated- there are multiple issues that may lead to water. The basement is usually dry, but in rains I get damp circles on the concrete and wet spots along the walls. No actual puddles. In freak heavy rains 3-4 inches in a matter of hours- like we had yesterday I get over a foot of water. Now that is mostly due to city drain backup not allowing my ejector pump to get rid of water in the pit. The sewer line and grey water line are all old tile lines- so there are lots of areas for water and sewage to force its way out of when pressure is high. In conjunction with the perimeter system I am digging I will install an overhead sewer which will eliminate 2 of the 3 underground clay tile lines. I have to leave the line that goes from the catch basin to the street because it captures gutter and surface rain water and directs it to the sewer. In regards to your question about "on top of footer". My footings go out beyond the rock foundation 3-4 inches on the side walls and almost 2 feel on the front and rear walls. Again this building is from 1890 and is 3 story brick- so the footings are substantial. I could easily place the pipe on top of the footing all the way around. That being said- I would prefer to have it deep so I am going to put it next to the footing. All videos I have watched on this recommend drilling seep holes into the foundation wall- almost every 3-4 inches to relieve pressure and release water inside the stone. That is why I asked- in heavy rains water runs into the holes I have dug in a steady stream- so there is a lot of water building up along the walls. I have significant spalling on the mortar joints and my brick face- so water is soaking up into the rock and brick. I would like to eliminate this.

[hubops]

I wonder what your neighbours' experiences are - during the severe flooding events ? .. it seems that the storm sewers are backing-up - any attempts to "sump-pump" that condition are futile - you are pumping water in a circle. Your only hope is a municipal improvement to the storm sewer - .. get you & your neighbours on the town council and git-'er-done .. bribery is known to work also. Your other, normal-state moisture/dampness issues seem rather minor / normal - for such an old house - in a flood plain.

John T.

[S N]

Hi John, My neighbors, have new buildings- so their plumbing (cast iron) doesn't have leaks and weaknesses like mine does (old clay tile). I also know at least one of them has 3 sump pumps, so they are so powerful that it pushes the water back out of their gutter outlets instead of into their basement- those gutter outlets are close enough to my basement that I am probably receiving a lot of their basement water in mine. My sump pump leads to my yard- my ejector pump goes to the sewer. I just unplugged my ejector pump during the flood to prevent it from circulating water for no reason. So my sump pump works as desired- I probably need to add another sump pit and put backup pumps in each one. I expect two sump pits, disconnecting the grey water line from the catch basin and adding it to an over head sewer should dramatically reduce future issues. Also, adding the perimeter drain should dry out the basement for the remainder of the year. I understand it may be "normal" to have wet spots in the basement but I don't want them- the previous owner had tiled the floor and when I pulled it up it was covered in mold. So for health reasons, pest reasons, and general preventative maintenance reasons, this is a solution. The best solution would be to redo all of my plumbing and layer my basement and walls with hydrostatic concrete and mortar, but I can't afford that.