Our basement floods (maybe 8-10 inches at the lowest point) in the winter. The water comes mostly from a couple of large cracks in the floor.
We already have a perimiter drain below foundation level and all downspouts are tightlined away from the building.
Assuming we have a situation where the water is coming up through the floor, do any of you have recommendations for an internal solution. (I am thinking of cutting a series of troughs filled with perf pipe/gravel routed to a sump pump)
Ideally we would like to convert this basement to living area (heck we’re paying property taxes on this space).
Replies
Bob:
Let me get this straight. You get 10" of standing water in a basement, and you want to convert the basement to a living space. Even if you can stop the water from coming in, which you can not not, the area would have a heavy moisture content, humidity. About the only use I would consider is a swimming pool.
Before you do anything, I would contact a qualified soils engineer.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
To clarify, most of the basement does not have standing water, roughly an 8 foot diameter area fills up over the rainy season fed by a crack running across the floor (waxing and waning depending on the severity and frequency of storms) with an average of a 3 inch depth. In the dry season there is no standing water but the cracks have a damp edge. A lot of water I agree but just a seasonal puddle and not really a swimming pool. : )
It seems to me that if I create an easy outlet for the water that otherwise would force it's way up through the cracks that would take care of the standing water. I'm looking for the best way to do that.
I assume there will always be high humidity in the basement and I believe that is a common problem in basements. Is that correct?
Yes, many basements have high humidity and it limits their use. Things mildew, smell bad, some people develop allergies, etc.
You need to determine which of these two situations exist:
1) groundwater levels are well BELOW the basement level and some source of water is pouring in and filling up the 8-foot diameter area. The solution is then to find the source and reroute it. Or,
2) the groundwater level rises above the basement floor. This would take and regional approach to fix and/or A LOT of pumping.
It sounds like you think it is case #1. If so, and you poke a large hole in the bottom of the slab/fill/underlying soil, it might drain out fast enough. Not a good long term solution because reinfiltration wells tend to clog up more over time then sources of water (i.e. the outgoing pipe gets worse while in incoming pipes stays the same or even gets "better" at delivering water to your basement).
Personally, I'd put in a few little wells to a depth 2 or 3 feet below the basement floor in the vicinity of your house. Sound them during the different seasons and track where and when the water is and what direction it is going. Note: I don't think it would be worth the $$ to pay a well driller, but a few driven wells in sandy soils or a few hand augered into silty or clayey sands can be done by yourself.
Would be cheaper to take up radio-controlled boat racing. Or make it into a Koi pond.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Water seeks its own level.
If you want to turn the basement into living space, it's pretty straight forward:
Jack up the house.
Tear out the existing foundation.
Put a strong boat hull in the hole.
Lower the house.
Edited 10/8/2002 10:45:23 AM ET by Bob Walker
Hmm, it's not looking good for the home team.
The overwhelming response seems to be that the basement might have to remain as it is, a light utility area.
I don't really want to put much more money into it if it's not going to really help. We spent a lot of money on the footing drain and I hate to send more good money after bad (or some cliche like that)
I don't know that it's not a high groundwater level. A pretty steady flow comes out of our footing drain all year long and the beach shows a steady sheen of water coming off the hillside all year long as well.
Reminds me of a quote I saw on the web: "If you dig a hole and put a bucket in it, it's a well. If you dig a hole and put a house on it, it's a basement."
Bob
"A pretty steady flow comes out of our footing drain all year long and the beach shows a steady sheen of water coming off the hillside all year long as well."
That sounds just like groundwater. And trying to change the local groundwater level is a difficult task. I do it all the time for clients but multinational, oil-company toxic polluters have pretty deep pockets. You give the impression of flows that you wouldn't want to pump continuously. So a few deep French drain (a couple of feet below the basement floor) seems the best option. But that is a long, deep trench, taken as far as needed until it daylights at a slightly lower elevation.
Have you considered going up? You're "paying property taxes" on that airspace as well.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Thanks a bunch for your answers and suggestions.
We are probably going to cut about 3 trenches through the floor and see if we can't route that water out to daylight (our house is on a ~20' embankment). My carpenter friend says that we can rent a hole hog and "drill" from the house out to the side of the hill which is about 40'.
I'll do some research.
Bob
ps. the remark about property taxes comes from the fact that our house is listed as having a finished basement. We have heard pro's and con's about contesting our tax rate.
"ps. the remark about property taxes comes from the fact that our house is listed as having a finished basement. We have heard pro's and con's about contesting our tax rate."
To be picky you can't contest the tax RATE, except to lobby the schools and other taxing groups when they set the budget.
But from my limited experience it is easy to contest the assest evaluation when there is a factual error in their data. But check the other items to make sure that there aren't other errors in your favor. Also try compare it to your neighbors to see if it is in line.
As to the basement. I agree with Boss you probably have bad drains.
A hole in the ground is difficult to keep dry in high water tables, but you have wart stuck on a hillside. Much easier to divert the water around it.
I have much the same constructruction and problem. I have a stepped foundation with the garage being had the higher elevation. The main floor of the house is slab with heating ducts in the floor.
About once every two years we would have a wet spring and then a down pour. The heating ducts would 1/2 fill with water and the next day be gone.
When we dug up the corner where the higher section meets the lower we found the drain line had just be left there and not continued down hill.
Once we did that all problem where gone.
Either you are getting too much water for you drain pipes to handle. When this happens when you get water in the basement, is the discharge pipe running full? BTW, does your gutter discharge into the same pipe? That could backup into the basement.
The only other possibility that I see is that there is a layer of trapped water that comes up in the middle of the basement, sort of a artisan well. Normally it can drain off, but under wet conditions the flow is too great.
"The only other possibility that I see is that there is a layer of trapped water that comes up in the middle of the basement, sort of a artisan well. Normally it can drain off, but under wet conditions the flow is too great."
I'm thinking that might be the case. Our perimiter drain is brand new. However I've come to the conclusion that the man that installed the system was WAY out of his league and I don't know what to do about that but I have serious doubts about the effectiveness and quality of their work.
The downspouts etc have their own seperate line.
Your description of the tax issue is accurate and I might take your advice and ask the neighbors about their assesment.
Thanks again!
Bob
"Put a strong boat hull in the hole."
ROFL!!
"We already have a perimiter drain below foundation level
........"
I have a hard time believeing that it's working properly.
"........and all downspouts are tightlined away from the building."
Not sure what you mean by "tightlined". What about the slope of the ground? Does it all slope away from the house? Gutters don't catch everything.
There is no idea so good that everyone benefits.