flooding basement questions

[Martha]

My cousin and I are working on restoring my old family home. It is a small, maybe 800 square feet, farmhouse. Half has a basement and half has a crawlspace. There is a hole punched in the basement wall to the crawl space. There is another opening in the basement wall which leads to a tunnel to a root cellar which has dirt walls and floor. The root cellar tunnel is on the south side. The crawl space on the west side.

The north side of the basement has leaked terribly for years. There were even occasions when the basement would fill up almost entirely with water. A sump pump manages to stop that from happening. The crawl space area is very damp as well and water will slowly leak from the crawl space into the basement. The crawl space had so many years of dampness that the floors rotted under that area of the house. We replaced part of those floors this summer.

My cousin's husband has a backhoe and he trenched around the north side of the house, put in drain tile and sloped the piping away from the house for quite a distance to a ditch. Unfortunately, I think that he did not dig deep enough and he did not go to the bottom of the foundation. So, the water problem remains as bad. The soil has a hard clay layer at about 4 feet down.

Any suggestions for the re-do? Part of the problem is that the house sits in a low spot on the property and it would be a major endeavor to regrade the land to slope away from the house and the slope will have to end in some kind of ditch. But we have a backhoe available and a front end loader.

Also, when the foundation is exposed should it be covered with any kind of barrier?

How about the crawl space? Should that be trenched around the house? How deep? As deep as the basement?

The picture is of the north side. Crawl space is under the single window where my cousin has her head poked in. The basement is under the double window. The basement is maybe nine or ten feet wide.

[calmloki]

Martha,

You kind of have a boat situation - with the ground sloping toward the house you are just trying to plug holes in your basement boat to keep the water out. On our old house we dug all the way around the foundation (no basement though!) and put drains out to the street that pick up the downspout water. Also painted the foundation block walls w/ a black sealing tar-like paint. Water still comes in easily.
When we had the back porch off i gave a city worker a few ducats while he and his backhoe were working nearby and he dug a 6-8' deep hole under the porch area. I stacked concrete block seconds in that hole and perforated a beer keg (long lived but not recommended - too tough and small) and removed it's top and have that surrounded by the block and a bit below ground level as a sump pit which feeds into the lines going to the street. Come the wet season it goes on and off after the area is saturated.
Most effective thing we did was to put gutters on house and garage and take that water to the street - making a fair chunk of our lot an effective desert that has to equalize in moisture before getting soggy. I see no gutter on your house - but a lot more country - so that may not be as effective, still, gutters would be high on the list of initial line of defense for me.

[samclem]

Martha,
Step 1) Lay 6 mil plastic down over the soil in the crawlspace, and lap it up the walls at least 6". The seams of the plastic should have a generous overlap. This needs to be done regardless of other steps, and will significantly reduce the moisture level (and resultant rotting) under that section of floor. It will also improve the indoor air quality.

Regarding the basement flooding: The experts always try to identify the cause of the flooding, but it's not always easy. It can be from either (or both) of two causes::
1) Localized saturation of the soil around the perimeter of the house, which then flows into the basement. This would happen after a large rainfall, and is especially likely if the downspous don't extend far enough away from te foundaton, if there s a hill slopng down toward the house, or if the house sits in (even a small) local depression.
2) Rising ground water. In this case, the local water table itself is rising to the level of the basement floor. Your basement becomes, in effect, a boat-- with many leaky places.

Problem 1 is addressed with good downspouts, sloping the soil away from the house where this is possible, and installing "curtain drains" in the soil to intercept the ground water when it is moving toward the house and lead it away to where it won't cause trouble.

Problem 2 is normally addressed with a basement sump pump, but can also be addressed with a footer drain and gravity flow to a lower spot if you are lucky enough to have a low spot (below the level of the footer) somewhere nearby and convenient.

Before we go farther:
1) Is there a hill (even a moderate one) that slopes toward this house?
2) Is there a place (creek, ditch, etc) nearby (within 100') that is lower than the foundation of the house? Is there such a spot that is at least a foot below the ground level at the house?
3) Soil type and quality: You mentioned a hard clay layer 4' down. Is the soil above this more sandy (free-draining) or clay-like?.
4) Is there a well on the property fairly close to the house? This can be a great source of info--it the well fills up to a level above the floor of the basement when the basement s flooding, you know that your problem is rising ground water.

As we "speak," I have a 7' deep trench that I dug around a portion of my basement. So, I'm living the problem right now. I've (over) researched this subject prior to starting the big-dig, I'll pass on what I think I know.

[deepc]

Think you hit the problem when you said the house sits on a low spot. Somehow you've got to get the ground water that's draining to the house around the basement without leaking in, and the drain to a ditch or wet well would be a start. Other drainage issues that you could address without too much pain include gutters on the roof to get the roof water away from the foundation (the photo does not appear to show any gutter on this side) and ensuring that no water pools next to the house.

You didn't say where the water is coming from but it sounds like a pretty healthy leak if it floods the basement. Is it cracks in the foundation? Up from a floor drain? In through windows or a bulkhead access? This would be another problem to attack, either with hydraulic cement, sealing the outside of the foundation (and getting the drain down to the base of the foundation) or both.

Last, as you found that wet can cause damage to the house itself. You can keep the crawl a lot drier by putting a vapor barrier on top of the dirt and running it all the way out to the foundation, then keeping the crawl ventilated. There's also a thought these days that a tight/insulated crawl is a better solution for some climates.

[Martha]

Quote:

Originally Posted by samclem Martha, Step 1) Lay 6 mil plastic down over the soil in the crawlspace, and lap it up the walls at least 6". The seams of the plastic should have a generous overlap. This needs to be done regardless of other steps, and will significantly reduce the moisture level (and resultant rotting) under that section of floor. It will also improve the indoor air quality. Regarding the basement flooding: The experts always try to identify the cause of the flooding, but it's not always easy. It can be from either (or both) of two causes:: 1) Localized saturation of the soil around the perimeter of the house, which then flows into the basement. This would happen after a large rainfall, and is especially likely if the downspous don't extend far enough away from te foundaton, if there s a hill slopng down toward the house, or if the house sits in (even a small) local depression. 2) Rising ground water. In this case, the local water table itself is rising to the level of the basement floor. Your basement becomes, in effect, a boat-- with many leaky places. Problem 1 is addressed with good downspouts, sloping the soil away from the house where this is possible, and installing "curtain drains" in the soil to intercept the ground water when it is moving toward the house and lead it away to where it won't cause trouble. Problem 2 is normally addressed with a basement sump pump, but can also be addressed with a footer drain and gravity flow to a lower spot if you are lucky enough to have a low spot (below the level of the footer) somewhere nearby and convenient. Before we go farther: 1) Is there a hill (even a moderate one) that slopes toward this house?

Yes, on the south side and very slightly on the north side, where the greatest leaking occurs.

Quote:

2) Is there a place (creek, ditch, etc) nearby (within 100') that is lower than the foundation of the house? Is there such a spot that is at least a foot below the ground level at the house?

There is a ditch about a hundred feet away. The ditch is lower than the level of the house but not lower than the bottom of the basement.

Quote:

3) Soil type and quality: You mentioned a hard clay layer 4' down. Is the soil above this more sandy (free-draining) or clay-like?.

Clay content high.

Quote:

4) Is there a well on the property fairly close to the house? This can be a great source of info--it the well fills up to a level above the floor of the basement when the basement s flooding, you know that your problem is rising ground water.

The well is new, drilled this summer. The well goes 60 feet deep. I'll ask my cousin in law how far up the water goes, but my guess is that the ground water level is pretty high.

Quote:

As we "speak," I have a 7' deep trench that I dug around a portion of my basement. So, I'm living the problem right now. I've (over) researched this subject prior to starting the big-dig, I'll pass on what I think I know.

I think I love you.

[Martha]

Good ideas on the vapor barrier for the crawl space. That will be next.

Several of you mentioned gutters. Gutters are something of a problem in our area as ice and snow often cause them to push off the house. Our old gutters were destroyed and we ended up pulling them off when we painted this summer.

[deepc]

Speaking of ongoing work, we've got new gutters going on this week and also have the snow/ice issue. The answer is to have the outside edge of the gutter just below the plane of the roofline so that snow/ice slide past. This is an issue with a high pitched roof but should pose no problem on the roof in the photo.

[samclem]

One thing to consider is: How certain do you have to be of the fix? For instance, f you are going to finish the basement right now (add drywall, flooring, etc) then you might need to go way over the top (more time, effort, money) to assure you get this fixed. If you can try a few things and see how they work during the rainy season, you'll probably end up doing less.

Here's what you might want to do:

1) Establish a local slope away from the house. This sounds easy--just move some clay-rich soil against the foundation and assure is slopes down for about 10 feet around the house, especially where the local slop now goes toward the foundation. The slope doesn't have to be much--just a 2" drop in 10 feet is enough. Pack things down really well. For added insurance, you can put plastic (or Tyvec) under the sloping dirt (also on a slope).

2) At the outside of this slope, install a curtain drain. It doesn't need to be very deep-- maybe a foot or so. This will collect the water during heavy rain periods and expeditiously get it away from the house before it has a chance to sink in and flood the basement. For best results, install this drain at least on the sides of the house where the local water is flowing toward it or collecting (the south and north side). While it might sound good to dig a deeper trench (and it would be more certain f collecting the water from sodden soils), you want to use gravity to drain this ditch, and it sounds like the exit point isn't very low.
--The drain: Dig a shallow trench. Maker it as deep as you can--to determine how deep, start from the spot where the drain will exit (nearby ditch, etc) and use a water level (long hose with a clear place on both ends filled with water). Get a reference level at the ext ditch and at several points along the rote of the drain. The pipe doesn't need to slope much-this isn't a sewer that will be carrying "solids" that need to be moved at a certain rate. But it DOES need to consistently slope down, or the water will slow down and the entrained silt will settle out and eventually clog the pipe. A drop of 6 inches over 100 feet is sufficient, though more would be better. Once you have the determined a common reference height line, it's relatively easy to figure out how deep the trench should be. Make it as deep as you can while still having good slope to the exit. Use smooth pipe (4" PVC sewer pipe), not the cheaper corrugated black plastic pipe--it will result in a much better job (better flow through the smooth pipe, less silting up caused by the corrugation, less chance for small low spots caused by the more flexible pipe,and you can run a snake through it to clean it out if necessary later, something that can't be done with the corrugated stuff). At the "high" end, run the pipe up to the top and install a screw-on cap so you can flush this thing with a garden hose or put a snake down it if needed later. Dig the trench 8" to 12" wide. Most books will recommend that you fill the trench with gravel or crushed stone and that you put a filter sock around the pipe or filter fabric lining the trench before you put in the rock. The fabric is intended to stop the soil from filling the pipe. I definitely do NOT recommend the filter sock around the pipe--the silty soil quickly fills the spaces between the crushed stone, and the sock will get caked with silt and soil in short order and stop the flow of water into the pipe-and your hard work will be for nothing. The filter fabric lining the trench will work longer, but the fabric may still get clogged with fine sit eventually-but its better than the sock on the pipe. I'm using a different method recommended by a US Army Corps of Engineers publication-filing the trench with sand ("cement sand") and using pipe that I cut my own slits n (the commercially available smooth pipe has holes to large for use with sand, it comes right in). I cut e slits every 4" using a radial arm saw. I did a small test, and after a little leakage of a smal amount of "fines" in the sand, no more comes in. The advantage of the sand is that it stops the flow of silt from the soil over a large area (several inches) rather than just at the single "face" of the filter fabric, so it will keep flowing much longer)

Anyway, put 3"-4" of stone (or sand) in the trench, put your perforated pipe in (maybe use two side-by-side while you are in there?) in the trench where you want to intercept the water flowing toward the house. After this point, put solid pipe from the perf pipe to the lowest point where the drain dumps the water in the ditch. The, over the perforated pipe, fill the trench almost to ground level with gravel (or sand). If you wan the most effective system, put the gravel al te way up tot he top and live with the look. If that's to ugly, wrap the filter fabric over the top (if using gravel/rock, not needed for sand) and put a thin layer of soil over the drain and re-plant grass. Over the solid pipe leading from the perf pipe to the ditch, just put the dirt back in (obviously).

3) Also--gutters would help. You may not want them now (ice issues and all) , but you might want them later. While you've got this trench open and leading to the low ditch, I'd also lay a 4"pipe to accept the water from these gutters and take it far away--just stub out an opening or two near thee corners of the house for future use. Along the same idea--put a 2" PVC pipe in the same trench (or pipe it into the pipe for the gutter effluent) to take away the water that is pumped out by the sump pump. In a lot of poorly-done installations, the sump pump ends up re-pumping the same water many times because it is dumped too close to the house.

At the point where all these pipes end in the ditch, put wide grates over them or at least drill them for copper wires and make a screen. Otherwise, little animals will go inside and build nice houses that will clog up your amazing drainage system.

Check that well when the basement floods. If the water isn't up to the same level as your basement floor, you've probably got a local soil saturation issue rather than rising ground water.

Sorry for the long note.

[Martha]

Thanks Sam and deepc. We will look at grading away from the house a bit, which as I said is a little because of the lay of the land and trees.

I'll talk to my cousin about the gutters.

The basement will never be finished. The goal is to fight the bad air quality and damage due to water.

[Martha]

BTW, the quality of the basement walls is poor. We have been filling numerous cracks with hydraulic cement. Deepc, we are plugging from the inside. Is it important to expose the foundation and plug from the outside?

[samclem]

Quote:

Originally Posted by Martha BTW, the quality of the basement walls is poor. We have been filling numerous cracks with hydraulic cement. Deepc, we are plugging from the inside. Is it important to expose the foundation and plug from the outside?

Exposing the foundation walls from the outside is a tall order--it's hard to dig up against the wall, and the potential for doing structural damage to the foundation is real. If you were considering finishing the basement it might be a worthwhile endeavor, but it doesn't sound like it in your case. Hydraulic cement on the inside is probably a good 80% solution--it won't stop the water, but it will help. Another step you can take: If the basement is still wet, you can jackhammer out the floor around the edge (within approx 8" to 12" of the wall) and install a drain pipe in gravel (or sand) slightly lower than the floor, and lower than te footer, if possible. This pipe would lead to the existing sump pit/sump pump. This will give your sump pump much better "reach" and should permanently end the wet floor problem if it is caused by a rising water table or local saturation welling up from under the slab. The contractor will normally put concrete back over the top, and you can even put a finished floor in later. BTW, if you have any radon problems in the basement, this is the very cheapest time to address them--the contractor can put in the air pump needed at the same time, using the same pipe as the feed. Problem solved.) Again, if you go this route, be sure to have a cleanout installed so you can later snake out/flush out the pipe should it ever silt up.

Edited to add: If a drain is placed under the slab on the inside of the foundation, the contractor can also include a special baseboard or line drain to go against the wall. This baseboard will allow any water that trickles down the inside of the wall to go straight down into the newly installed drainpipe under the floor. Obviously, this won't keep the wall dry, but it will stop the water from puddling on the floor. If you g othsi route, you wouldn't be able to use the perimeter drain to also evacuate radon, as you'd be draing air from inside the house rather than under the slab.

[harley]

I don't have this problem currently, but this thread is a perfect example of why I love this forum. I've looked for this type of info for other problems on all sorts of DIY type sites, and you never see detail and considration like this. Way to go, ladies and gents.

On a side issue, I hear moats are coming back in style with the approaching apocalypse. Sounds like you have a perfect opportunity here.

[ERD50]

Quote:

Originally Posted by Martha BTW, the quality of the basement walls is poor. We have been filling numerous cracks with hydraulic cement. Deepc, we are plugging from the inside. Is it important to expose the foundation and plug from the outside?

I will just add that trying to plug the leak is not a solution to this kind of problem. It would be like a game of Wack-A-Mole, but worse.

If you actually were successful at plugging the leaks in the basement floors/walls (I'd be very surprised) you could be in for bigger problems. Since the water is still there, you really created a dam with many thousands of pounds of water behind the wall ( water ~ 8.3 #/Gallon). You could end up with the walls caving in. This would be bad.

Sealing the walls is to prevent seepage from dampness, or a little water running down the wall, not hold back water that is rising to fill the basement. Think about how a ship works - hmmmm, it floats and lifts many tons of cargo when you seal it's hull. You would be building a ship if you managed to seal the "hull" (basement) of your home.

As expected, samclem has the right approach - you need to give the water a different place to go, and the best tool you have is gravity.

-ERD50

PS - this forum seems like a pretty nice place to me - one person posts a problem, and look at all the help they get. Quickly, and good info too. Not bad at all, IMO.

[Martha]

No one spends a lot of time at this house (I can't sleep there because of the mold issue). Do you think I should do a radon test? The reason being that since we are working on the basement it would be the time to fix that if it is a problem.

Please note, this house is worth very little money and odds are it will not be sold in our lifetime.

[harley]

Affirmative on the radon test, especially if it's a regular problem in that area. Most testers would be able to tell you what percentage homes around there end up needing remediation. It's not that expensive, either to test or fix.

[samclem]

Quote:

Originally Posted by Martha Do you think I should do a radon test?

I don't know about the legalities (is a test required before sale anyway, etc). You're no the kind that would fail to disclose this type of thing anyway, so the only question is--would you prefer not to know?

The tests are cheap (approx 10 bucks), available at Home Depot and Lowes, and consist of a little packet that you leave open in the test area for a few days, then seal it up and mail it back to the lab. The directions on the package are very complete.

If you want to know about whether radon is a problem, you'd probably want to do one test in the basement and one in the main floor of the house. Older, draftier houses are less likely to have a problem, but basements can be an issue.

Would I do the tests? Probably. I'd just rather know.

[OAG]

Quote:

Originally Posted by Martha No one spends a lot of time at this house (I can't sleep there because of the mold issue). Do you think I should do a radon test? The reason being that since we are working on the basement it would be the time to fix that if it is a problem. Please note, this house is worth very little money and odds are it will not be sold in our lifetime.

Some counties (like ours Franklin Country Ohio) gives these Radon Test kits out free. They take about 30 days to run and require a calm environment. If these point to a problem they have a follow up kit that is a little advanced. We did ours and it was fine with both kits (did the second one just to be sure in our own minds). Here the Fire Department hands the basic ones out and you have to call some other Agency to get the advanced kit sent to you. You should be able to get one from your Environment Protection agency. Personally, I would NOT go to a Radon Remediation company UNTIL the free kits pointed to a PROBLEM (but I am a born cynic).

[CCdaCE]

Radon map.

I assume that place is in MN. Moderate risk assuming it's in the arrowhead.

-CC

[limpid lizard]

Place a piece of culvert on end on the basement floor. Make holes or prop the end an inch or two off the floor. Hire a cement truck to pump the basement full of rock. Not cement, but rock. Place 6 mil plastic over the the rock and crawl space floor. Put a sump pump in the culvert. Pump the water away from the house and pretend you never had a basement.

For odor control, run a 4" stack of DWV pipe up the side of the house for a vent.

[Martha]

Actually, I thought about "removing" the basement. But that would entail building something for the furnace and water heater so I think the basement stays.

Not much can be done now until spring.