[bassheadjohn]

I have been reading many threads on this site and many others and I have not come up with a solution to my problem. I decided to build a freestanding deck. It is going to be placed about 8 feet above ground level. The dimensions of the deck will be 16' wide and 12' out off the house. I placed my outer posts at 11' and my posts closets to the house are 2'.
I began to dig the holes closest to the house to code depth which is 36". At 2 feet down I started to see water. I kept digging expecting to find more solid ground. The deeper I dig the softer the earth gets. I used a shop vac to clear it and the water keeps returning to the holes. We haven't had rain in about a week. I marked the holes and the water keeps filling up to that level, about 1 foot. The holes I dug at 11' off the house were dry. Not a drop of moisture.

My house is brick veneer so I am very hesitant to do a ledger board attached to the house. I have already dug 44" inches and I am still getting the sloppy mud. Any ideas? I thought about running the posts right against the house, setting them on the house footing and anchoring them to the foundation. The other option might be to bring the deck height down about 7 inches build a step down. Could I put a ledger on brick that has hollow core block behind it? Do I need a french drain? My front yard is higher than the back yard. I have had people tell me to let the holes dry up. I have been shop vacing them out constantly for the past 4 days and there is no sign of drying up. I have heard just dump a dry bag of cement in there. The holes fill up rather quickly. I am getting about 6 inches of water every couple hours. The water levels off at about 1 foot. I feel like building on this ground is unstable. Please someone help..Too many sleepless nights for this guy!!!

 

[user1007]

When I built decks, pergolas and things in Foster City, CA (built totally on semi-solid landfill) we literally had to have a tide chart handy as holes would fill up at high tide. A friend married the woman from Foster City but when they were dating he needed a tide chart to get in her apartment as the door would not open until the tide went out again.

It sounds like you may be sitting on some sort of artesian well or aquafore situation. You might check with PA water survey folks? They should have charts of the overall water situation near you. There may be restrictions on what you can do to alleviate your current situation. Are you near the river at all, by the way? Are you flood prone? Nothing in your title documents?

I suppose it could be a slow leak in plumbing somewhere but your water bill should reflect that. Are your downspouts draining into clay or pvc pipe. It could be leaking. Here we can drain them that way because of the load on the sewer.

 

[bassheadjohn]

To reply to your comment. There aren't any streams on water within miles of where I live. The downspouts discharge into the yard and gutters are at a questionable height below the roof line. I plan on re-routing them and discharging them as far away from the house as possible. The water that is collecting in the holes is very clear looking and has no smell to it. I am doubting it has anything to do with sewage. As far as a leak in the water line,my supply enters in from the opposite end of the house and bills seem to be normal.

 

[oh'mike]

Be patient--we have some concrete guys here that may look in---

I do find it odd that the far holes are dry and the near in ones are wet--

How old is the house--any chance of an old cistern or leach lines that are abandoned?

City sewer and water?

 

[bassheadjohn]

Talked to a cement guy today...

I talked with a cement guy that was a foreman with a rather large company in this area. He mentioned there could be a number of possibilities that the water is there and at different levels in the holes. He made the following suggests and thoughts.

1. Mark the height of the water.
2. Clear out as much water as I can.
3. Toss in a shovel or two of gravel and hand level.
4. Run rebar horizontal across the hole and into the earth a few inches. This would stabilize hopefully eliminate the concrete from wanting to fall or rise.
5. Vac out any water that appears to may have risen above the gravel.
6. Toss in a "tight" (dry) mix of concrete into the hole.
7. Add concrete to about 4 inches above the water level.

His theory is that water will level itself. With the concrete present the water will go somewhere else and level out.

Seems valid But to me it still feels like a gamble.

 

[bassheadjohn]

Reply to Oh'Mike.

The house was built in 1958. Only thing that I know that is questionable it terra-cotta lines that are nearby. I had a plumber put in a considerable amount of dye into my drains and I haven't touched the holes in 2 days. The water levels out to the same height and no dye..yet. Of course it might take some time to move through soil.

 

[user1007]

Seems valid But to me it still feels like a gamble.

Me too and it could come back to haunt you and perhaps in a costly way. :huh:You should find out what is happening and not just rely on water to find low ground. If you start dumping dry mix in the holes you may find you just have to dig it out in short order.

Among other things if it is something you have to dig to resolve it would be a shame to get your deck built only to have to pull it apart?

Hadn't thought of a cistern but have certainly encountered enough of them to know they can create problems if they are not filled in. You may need a permit to fill one in though, especially if there is any chance of leaching into a drinking water supply, stream or river.

 

[bassheadjohn]

Cistern free

I am real sure there isnt a cistern under or nrar the house. I am ruling that out. I woke up today thinking i need to figure out where this water is coming from. If it is a spring near that i disturbed enough soil to free up some water can i build on it? If it is a spring wouldnt the hole continue to rise and not level off? I may concentrate on my downspout dischsrge and gutters a little while. I may have this terra-cotta looked at. I am still scratching my head over this and still have a door to nowhere. With a growing family we are probably going to sell in the next year or so once i finish my projects to bring more value to the house. I am pretty sure a door to nowhere will not yield positive results at selling time.

 

[oh'mike]

Tell us more about the house--age and plumbing---

A picture would help--

Also--if you have a leak in the main incoming water line--and the meter is inside the house--your meter would not register the leak.

Do you have perimeter weeping tiles and a sump pump?

Basement or crawl space? The dry holes away from the house make me think the water is coming from the house systems--not ground water---post pictures.

 

[hand drive]

I've run into that a few times and it was usually the foundation drain for the house releasing water that just sits in the drain.Some foundation drains do not drain well so water basically sits in the drain beds in some cases and when digging near the drain the water finds the new hole. If the backside of the house has lower grade than the front that could be why it is taking so long for the pressure to relieve itself. I have run into springs under houses too with crawfish and everything.

As the concrete guy mentioned, if the water level remains constant then you should be able to work with it with gravel and what not

 

[bassheadjohn]

Picutres

I will provide pictures later this evening. The house is a 1958 ranch house with a basement. I do not believe there are an exterior french drains. Definitely no sump pump, no crawl space. The house is built on a footer with a block wall foundation. The basement is your standard concrete floor/slab. The front of the house the ground is level with the top floor. The rear of the house the ground is level with the basement, a floor lower. My water enters the house from the street opposite from where I am working. All lines in the house are above ground. Sewage drains towards the street opposite where I am working. I am going to have the drain near where I am working inspected. Its a tough $250 but may answer some questions here. I will take some pictures today and post later this evening.

 

[bassheadjohn]

Pctures set 1

Here is a set of pictures of the layout of the land that I am dealing with. Most have labels. More to follow...

 

[bassheadjohn]

Picture Set 2

Here are the rest of the pictures. This gives you a little idea about terrain and details about the house. The house sits pretty much on the top of a hill. As you can see I am working on the back portion of the house. Interestingly today I decided to clear one of the holes that had a questionable gray water enter I got a bunch of what seems to be sewage that oozed into the hole. I believe I have a brown terra-cotta under there. It seemed to tunnel back towards the house. There is some plumbing just behind the wall. It explains a little. I still am wondering why all the water is there...I am currently working on removing gutter covers that seem to send more water over the edges than catch it. I am also going to run the discharge of the downspouts back and over the rear hill of the yard. That should help with some of the ground water. This may correct the problem this may not. Until these holes dry up PLEASE continue to offer suggestions.

 

[bassheadjohn]

missed 1

This is the last picture. this sludge re-appeared a few minutes after using a shopvac in the hole. Who knows how much of this is under there.

 

[Blondesense]

OK, I admit I'm blonde and this is waaaaay out of my experience, but would it be possible to take a sample and have it tested for chlorine. If so, it would at least tell you if this is coming from the house or natural.

 

[bassheadjohn]

Chlorine Test

I talked with a pool guy I know. I am going to have it tested but as he mentioned even if it comes up as a negative doesn't mean that it isn't from a water line. He mentioned chlorine levels are pretty low in tap water and as it travels through the ground pH, minerals, impurities etc could through results off. So if it is a positive then we know for sure. If it is a negative we still don't know for sure. I will post the results this evening.

 

[oh'mike]

OK, ......... but would it be possible to take a sample and have it tested for chlorine. If so, it would at least tell you if this is coming from the house or natural.

You have a logical and analytical mind---

 

[bassheadjohn]

Water receding

Just a little update. The water has been started to recede. I watched as rain came down the other day and noticed my driveway has a slope towards the areas that I am getting a lot of the water. I am starting to think this is just a ton of ground water. If that is the case once these holes dry up can I pour my footers. Once it rains again will this cause the soil to saturate and the footings to sink? I will continue to post updates as I see things changing.

 

[hand drive]

Just a little update. The water has been started to recede. I watched as rain came down the other day and noticed my driveway has a slope towards the areas that I am getting a lot of the water. I am starting to think this is just a ton of ground water. If that is the case once these holes dry up can I pour my footers. Once it rains again will this cause the soil to saturate and the footings to sink? I will continue to post updates as I see things changing.

the idea is to dig down past the soft mud back to dry/solid after the footings have had water sitting in them and then pour the concrete. what you have there looks like ground water trying to find somewhere to go. After you fill the holes back in with the concrete and back fill the water will not go back there because the holes are filled in and not open...

 

[bassheadjohn]

deeper? sewage nope, junk backfill yep...

Handy, you think I need to dig deeper? I am already at about 44 - 48 inches on these 2 of these holes. I probably have another foot of what feels like very silk soft clay and muck. As I dig deeper wouldn't I expect to have the same results. My thinking is as I dig I will continue to saturate the new earth as I open it up. Additionally I am running out of handles on my post hole digger. As I go deep there hole seems to limit the amount of width I can spread the digger handles. Widen the hole?

Additionally, new things have come to light. I had a camera run through my drain in the digging area. Surprising the terra-cotta was in great shape. A few bucks later and half of a concrete floor replaced I learned there is no drain break. The gray muck is a mystery to me. Poking around in the holes I found interesting things filled as backfill. One thing i found explains why the bottom of one of my hole just collapsed. The builders tossed a piece of terra-cotta flue in as backfill. he scary thing about that I was THis flue was only a inch or two below my required dig depth. That could have supported some weight but for how long. I can't imagine what would happen when on corner of my first story deck dropped about a foot. I found a cinder block along with other things you would typically find as backfill.

Other project updates I decided to redirect my downspouts. Tomorrow morning I am picking up a trencher and my downspouts will have a new home. I also watched the rain the other day on my driveway. It seems that due to the age of the driveway a decent amount of settling has occurred. I observed water puddling up near the rear of the driveway. In the same area as these holes. I am thinking I may run this trencher along the edge of the driveway and create a trench the drain that will help redirect any of this water away from the house. I have also tossed the idea of working with adjusting the grading near the house. I havent filled in the holes but I am running out of summer to get this done.