Greetings all
I’m hoping to get some suggestions on how to stop my crawlspace from flooding. Hopefully the crude drawings will illustrate the problem well enough.
Runoff from my neighbors driveway fills the swale between the drive and my house, and if there’s enough rain it will overflow into the crawlspace. As you can see in the drawings the poured foundation only extends a few inches below grade, and the top of the foundation is below the level of the neighboring driveway, so to get the grade high enough to natually direct water away the grade would be above the foundation.
A couple of my possible solutions-
1. Pour a curb along the neighbors drive which would direct water to the front yard. Cons- expense
2. Sump pump in crawlspace to pump water out. Cons-Water is eroding the earth under foundation and causing settleing, so this is more of a closing the barn door after the horse is out.
3. Sump pit on outside of house in swale to pump water away or around house. Cons-Appearance and Freezing concerns in winter
4. Jack up house and put proper foundation under it with perimeter drains and sump. Cons-$$$$$$$
Anyone have any better thoughts, Think it over while I check on how the pumping is going.
Thanks
Replies
Install a French drain on both sides of your house and combine it with a sump pump to the street. Check with city for runoff water flow into local curb and drain system. Also, it's probably not a good idea to run it over the sidewalk as this could present a slip hazard . Run it under and out through the curb itself and into the cutter.
Thanks for your thoughts.
The problem is the foundation is only below grade about 6 inches, and since water takes the path of least resistance, I'm afraid it would simply bypass the drain tile and run into the crawlspace.
I suppose I could line the drain tile trench and up the foundation a bit with plastic, but how do i keep the water in the drain tile as it goes under the foundation to the sump pit?
After you put the drain pipe in and wrapped it with drain cloth, fill the trench to grade with 3/4 gravel and not soil. Mine is about 2 feet deep and 18 wide at the surface. Then run the pipe to a sump and you could locate the sump outside the crawl space entirely. It should still keep your crawl dry as long as the highest level of the drain pipe is below the crawl elevation.
Something like this?
That looks workable but only if the outlet(shown at the rignt) is indeed lower in elevation and drains or slopes away from the house. By the way, if you do have a big enough grade difference, you could just dig a longer trench and let gravity take the excess water to daylight on the downhill side rather then going to the effort of installing a sump pump and electrical wiring hassle.
Another idea is to install a curtain drain midway between your neighbor's driveway and your house. Basically you just take your "CRAWLSPACE_CROSSECTION_2.bmp" drawing and move the footer drain you have drawn in about 2' to the left. Is there no way you can get the drain tile pipe to daylight? ie - so that no sump pump is necessary? In your lot layout drawing you said that the neighbor's driveway slopes from back to front on the drawing you don't show what is front and what is back on the picture....
Just to try to get a clearer picture, again, regarding your neighbor's driveway, where it is closet to the front corner of your house, what is the elevation relative to your house top-of-foundation and how much above the street would you say his driveway is at that point. Same question for the back corner of your house that is closest to your neighbor's driveway, and again, how high is that point as compared to the street.
When we are doing lot grading we often use a laser. It can be difficult to see small differences in elevation just going by eye. Even guys who have been operating heavy equipment for decades can have trouble with that.
A site level is a very cheap second to the laser, or even a builders level. The idea would be to generate a drawing something the attached that I threw together real quick. Edit: OK - I messed up too. The in the quick drawing, the street is at the bottom...
Edited 9/14/2008 8:43 pm ET by Matt
I updated the lot layout with more info. My neighbors drive is on the left side of drawing. Neighbors drive is at a higher elevation than the top of my foundation.
I'd construct a drainage swale along the side of the house and direct it out to the front of the house. I agree w/ your first notion that allowing the water into the crawlspace (controlled or not) is not a good idea (IMO).
Are you above the level of the street?
A curb along the neighbors drive sounds like a reasonable option, too. It eliminates the bulk of the problem before it gets onto your property ... and where the problem should be handled. In many locations of the Northwest, you can no longer build and allow storm water to leave your property ... even to the street. But that isn't always doable in other locations that may have more storm water.
I tried a swale, but since the lot is so flat and level, I just got a pond that eventually overflowed into the crawlspace.
yeah ... it would have to like slope out to the street or other location. If you know how much water is involved, you could do a drywell ... but a curb against the neighbors driveway would keep the water away ... although that may have some issues (legal/liability wise) ... talk w/ P&Z about that kind of thing. Where I'm located now, I've heard there are issues if you don't allow 'natural' runoff from e.g. your neighbors ... i.e. blocking runoff from coming onto/through your property. 'Course it isn't natural if it is largely created by man made construction forcing water to gather or run off your property. Seems like you would be allowed to take steps to mitigate water coming from your neighbor ... and w/ all due respect for you neighbor as I'm guessing it wasn't his fault (i.e. a preexisting condition). Might be worth a chat w/ the P&Z office to see what they may have to say.
Sounds to me what is needed is a retaining wall right on the lot line. Regarding runoff from the neighbor's driveway, it is difficult for me to believe that the neighbor's driveway is flat front to back. It very probably slopes either slightly toward the street or toward the back of the lot, not just toward the poster's house. If it is paved the water is gonna run off even if some kind of curb or retaining wall is erected. Heck - the OP hasn't even told us what the driveways or the street are made out of.
Sounds to me what is needed is a retaining wall right on the lot line. Regarding runoff from the neighbor's driveway, it is difficult for me to believe that the neighbor's driveway is flat front to back. It very probably slopes either slightly toward the street or toward the back of the lot, not just toward the poster's house. If it is paved the water is gonna run off even if some kind of curb or retaining wall is erected. Heck - the OP hasn't even told us what the driveways or the street are made out of.
That was my first Idea and would work, just expensive. His drive is sloped to the street about 6" in 50', but it is sloped to my house about 6" in 10'.
Driveway and street all asphalt
Stop dinkin' with these pumps and shid.
Put in the retaining wall as the neighbor's runoff is not your responsibility. Let him deal with it.
The wall will allow better grading of your own lot so any rain will flow away from the building.
Walls can be cheep or expensive. Picking up rocks along side the road or from farmer's fields can be a cheep source of material. Stack them well, as you're only going up 18" or so and don't need a permit. Use a fabric behind.
RR ties can be cheep, also, but don't last as long.
If you wanna do it nice, get some real nice retaining wall blocks. Cost more, but will take less time.
Understand the cheepest part of the wall is YOUR labor in digging the base and setting up the materials. It's also the most important quality control factor in building it right from the first step instead of several times because you cheeted somplace.
You said: "I tried a swale, but since the lot is so flat and level, I just got a pond that eventually overflowed into the crawlspace."
Yet on your drawing it says "Lot slopes down 18" from left to right" or something similar.
Conflicting information.
I updated my drawing some too. Take a look.
Really though you are gonna have to give us some better information - actually data. Get some kind of grade measuring device. Like the little plastic site level I linked to above. I think they even have them and HD for like maybe $12. It takes 2 people to use it. One to stay in one spot and uses the tool and record the information, and the other to walk around to different points on the lot and hold a graduated "rod" (sometimes a tape measure can be used) while the first person looks at it through the tool. It works well if the tool is placed on top of a stick, maybe 5' long (depending on your height) to ensure that the tool is held at the same height during all the height measurements.
Assuming your foundation is all one level (not a step down foundation), you can probably assume it is level and get height readings above grade at the 4 corners with a tape measure. That would be a good start. And we need to know how high the top of the house foundation is relative to the street out front. Is there curb and gutter at the edge of the street? And we need some kind of height readings for the back corners of your lot. Just to say "it looks level" doesn't cut it.
Otherwise, if you can't supply some better information the answer is: "hire a professional".
One final word: Water in the crawl space is serious business. It will mess your whole house up; rot the floor system, and the moisture can permeate through the whole house all the way up the the rafters causing various moisture problems including possible mold and mildew - even in the attic.
The posters are chomping at the bit for a bit more info. It seems that there must be a slope down to the street. Even seemingly flat lots have more slope than you might think. I had a driveway on a flat street lot ... 20 ft sidewalk to garage. It looked flat ... but I measured 6 inches of slope to the sidewalk! When it comes to drainage even a little slope can mean a lot. A 'flat' street is often sloped to drain to storm drains.
At a minimum, it looks like the area slopes down left to right ... meaning the street goes up hill right to left. If you put in a swale that runs along the house out to the front yard ... you would have an opportunity to then divert the water down hill ... to the right and maybe out toward the street.
I'm having difficulty believing the driveways are both flat front to back. There must be some slope, isn't there? Even if so, a swale should work if you simply bring it to the front and then allow it to drain downhill. At that point, you have some options. You have indicated there is some slope ... which is why you have the problem ... so you should be able to work with it. You got a pic (to help your drawing) of the situation?
I gotta get to work, but will get more info and maybe a pic later.
Thanks all
Edited 9/15/2008 9:48 am ET by 9ENGEL
Do a concrete swale, cut the expansions, dont use separation material as the water will seep through.I place these often for these problems. it moves water quickly. You can make a screed with a jigsaw to create the curvature.