Wet basement. I'm doing foundation waterproofing work

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rdsrds123

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Hi everyone, My house is the second one from the end. that's my red Ranger parked right in the way of where I'm digging. :D I'm over my head here technically, and neck deep in water, otherwise...I could use some help.

I have a 170 year old row house in Downtown Baltimore Maryland. I've owned it for a year now, and I knew it had big water problems in the basement before I bought it, but not this big. I love this house that is full of storybook charm, but the water is a problem. I had a Regional Waterproofer come in and they sold me a sump and drain tile system, which did little to help anything, but it lightened my pocket of $9300.

Now, I want to excavate the front and rear foundation wall of the house and parge and tar the foundation wall. I had to jump through ten hoops at the One Stop Permit Shop here in Baltimore to get ready for the work. I'm ready now. Among the hoopettes I hopped through were the permit to block the sidewalk people. the regular building permit people, a City engineer to approve my plans, and the Historic neighborhood folks. It was many more than one stop. The permits will probably end up cost more than me doing the work.:clap:

Anyway, I started digging out the front foundation today and hit concrete at 8 inches of depth. Apparently this 2' X 6' slab is a foundation for a planter. It extends two feet out from the front of the house, and runs between the steps on one edge of the 11'8" wide house, to the neighbors house, or about six feet. Below this, I have gas, water, and electricity lines, and also obsolete water and gas lines that are still there-- five lines I have to watch out for.

I want to remove this concrete and continue digging down to the footer. Should I just water proof the best I can and not remove the concrete?

There is no actual footer in this house. I want to dig to about 8 inches below where the slab is and put gravel there and a perforated drain pipe running the 6 feet with end caps. I'll cover this with about 4 inches of gravel.

I plan on parging in two coats and then two or three coats of a tar substance I bought at Home Depot. I'll calk between the steps and the wall of the house, etc. I only have to dig about four feet down total.

Question: Can I backfill with pea gravel instead of dirt? I read that when sinking fence posts that are not of a rot resistant wood, to sink them in gravel. The idea is that the gravel will cause the water to fall away from the posts, and the posts will not remain wet all the time. I'm thinking the same idea here. The water will fall down to my sump system. could it hurt the neighbor's house? Is a backfill of gravel considered better than dirt?

Actually, I also want to put a plastic vapor barrier between the final coat of tar, and the backfill gravel. Then I'll put a barrier a few inches below grade, from the house, out about two feet towards the road to drain the surface water away. I'll glue it to the house with tar, like roof flashing.

Could anyone please comment on these plans and tell me if any of these ideas are not good ideas? Also, any alternative ideas are appreciated.

Thanks guys!

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I hope these are not duplicate pics and show the work I'm doing better than the other pictures. I cannot see them well when uploading them, so I'm sorry is they do not show the work.

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not really sure what to tell you about the concrete. I guess you should make sure it is not attached (part of) to the basement walls before you do anything.

There is a product sometimes called 'curtain drain' that you should put against the outside wall after you seal it. It is a plastic sheet, dimpled and covered on one side with geocloth, essentially creating a small gap between the earth and your wall. the concept is that the water will travel down to a french drain where it can be carried off. (I know one of the guys has a pic of the stuff).

And yes, the gravel is a better idea than dirt; it also allows the water to drain better. Of course, once the water is deflected down, you need the french drain to channel it away.
 
Always a guess when you work on old building.
It looks to me like you have a window well to keep the water away from the brick wall around and below the window, which should have had no fill in it.
Water from that area probably was to run down the gutter drain that you have there.
Brick absorbs water and water drains down the inside and should flow out holes left between some of the bricks on the bottom row and above the doors and windows.
If that system didn't work because someone backfilled to high or plugged the holes the brick will wick water to the inside.
Solving this problem may not solve water coming from the houses next door.
The guy that did your drain inside was after money more than solving problems
He should have told you to lower the fill around the window for staters.
Then on the inside he should have draped the wall with dimped plastic that S&S talked about that would have drained the wall into the drain he installed
This could still be done on the inside by removing a few inches of concrete agains the wall installing the plastic and repair the concrete, may be the easiest way.
On the outside digging and working a 4 or 5 ft ditch can be dangerous but you plan sounds good I would use the dimpled plastic but working under that slab would be really questionable and removing it, well maybe, but you would want to be care full it might extend right into the wall, Then you would want to have a coring co come and cut it off.

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I would be taking a real careful look at that slab to see if there is a seam between it and the wall. If you can see a seam, then you can take a whack at the slab. It also may be worth digging around the outside edge to get an idea of how big the slab is.
 
What i can tell you are much better focusing on keeping water out of the building than creating a sort of pond system in your basement.
For example you could back fill with open cell foam pieces mixed in that will hold a great amount of water.
 
b
ack fill with open cell foam pieces mixed in that will hold a great amount of water.

I have to wonder WHY you would want to hold a 'great amount of water" against your foundation wall, when you could use gravel and a french drain to just move it away....
 
Bryce is correct the main cause of a wet basement is wet soil around the foundations. A soil failure. Foam will hold lots of water and air. While dirt won't hold much water or air at all. It will be mud, so saturated with water, it can not dry out, then it enters the basement.

The grounds should get wet with rain, absorb the water and after a few days dry out almost completely. The ground shouldn't drain out to China. Gravel will hold no water but some air.

Still do your french drain and blue skin over the foundations. Should be 2"+ of polystyrene insulation around the foundations, then some well conditions soil that will absorb lots of water and dry out quickly is ideal. If the water never gets to the drain of the foundations all the better. The water will still go under the slab and into the basement that way. I guess new house build the slab over a layer of polystyrene and vapor barriers, but not the old ones...
 
Bryce is correct the main cause of a wet basement is wet soil around the foundations. A soil failure. Foam will hold lots of water and air. While dirt won't hold much water or air at all. It will be mud, so saturated with water, it can not dry out, then it enters the basement.

The grounds should get wet with rain, absorb the water and after a few days dry out almost completely. The ground shouldn't drain out to China. Gravel will hold no water but some air.

Still do your french drain and blue skin over the foundations. Should be 2"+ of polystyrene insulation around the foundations, then some well conditions soil that will absorb lots of water and dry out quickly is ideal. If the water never gets to the drain of the foundations all the better. The water will still go under the slab and into the basement that way. I guess new house build the slab over a layer of polystyrene and vapor barriers, but not the old ones...

You have not considered the weight of the water held in the dirt now pushing on the foundation. It is all about drainage.
 
If you can keep the water close to the surface evaporation can play a part. Water is going to seek its lowest level and will follow the path of least resistance. Draining it away thru a path of low resistance and making the pathway into the house a higher resistance to flow is the answer to keeping it out. If you have no chance of keeping it out then collection and pumping out is a last resort.

Water in a standing column will generate a hydrostatic pressure based on its height. It’s possible to have water coming from underground and building a pressure from some distance away. In that rare case tapping it off by giving it a pathway to the surface can help. I don’t think that’s the case with the OP here.

I’m in agreement with Neal it’s all about drainage.
 
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