This is long, but well worth it. : )
I would appreciation some opinions on the appropriateness of my proposed basement water issue solution..
Here’s the situation: I have been in our 15 yr old home about 3 yrs and have gotten water in the basement twice. Luckily, only my shop and several carpet remnants for the kids to play on are currently located in the basement, but we are considering finishing the space, so I need to solve the water issue.
Both water events came after very significant rains with storms dumping in excess of 1-2 inches per hr.
We have a walk out basement with no sump. I presume they installed drainage tile to daylight when they built the place, but I can find no exit points now.
They worked pretty hard to make the backyard grading accommodate a walk-out: The ground outside the basement door does slope away from the house, but minimally. The yard then slopes slightly upward after 20 feet or so.
I am pretty confident that I can explain the origin of both water events: Poor down spout drainage. The first was after my wife put in a flower bed beside the house. She installed edging and left the down spout to drain inside the bed, forcing water to accumulate against the foundation. Easily solved… I can’t get too upset when she is willing to install her own flower beds! The second event was likely due to a clogged gutter, resulting in water dumping out next to the foundation (and into another flower bed). Again, this was easily solved by cleaning out the gutter.
During both water events, I observed water “flowing up†from the cracks in my basement floor. This leads me to believe the water flowed down beside the foundation, likely filled a drainage tile with no exit, then flowed under the floor until it raised to a level which forced it up through the cracks.
Now I know the “right way†to solve this includes keeping the gutters clean, but I’m human, and finding the drain tile (assuming it’s ther) and assuring it exits to daylight properly. Even if I did that, however, the low point outside my basement door is such that I believe it would need to turn up to exit.
I am, of course, interested in minimizing the excavation while working toward a sure solution (even if I forget to clean the gutters once in a while, which I promise to do religiosly from now on!). I am thinking of installing a sump.
I realize that a properly installed sump will be tied to the drainage tiles, but I figure the observed water pushing up from the floor cracks is a pretty good sign that if I dig a hole through the basement floor, water will collect in it before pushing up through the cracks.
Am I nuts?
BTW – Is installing a sump in this way as easy as it seems? Just cut through the floor, dig out a hole, put in a sump pit liner (with the bottom cut off and hole through the sides for water to enter), file the rough opening with gravel and cap around the liner with concrete?
Edited 6/8/2005 7:13 am ET by NCLAQUER
Replies
There's all the obvious stuff about keeping the water out, which you seem to have already considered.
As you say, though, if there remains a risk that you'll get water, a sump is nice to have. Cheap insurance.
I just installed one last week - used a hammer drill to break up the floor in the low corner, built a simple wooden form, poured concrete in the bottom of the hole, then dropped my form in and poured around it, troweling it even with the floor. Simple and fast. I'm not sure I see the value in poking holes in your sump liner, unless you think the entire water table is rising and this will allow you to pump it out before it ever rises to floor level. From your description, your problem is more localized, and a moving target at that, so unless it happens to occur in the area of the pit, I'm not sure the holes help.
I didn't tie mine into anything - just ran a flex hose up and out through a convenient gap in the mortar between old stones, and dragged the end of the hose away from the house.
One key piece of advice - buy the pump first and follow the directions (Captain obvious, I know) for the hole. I went over to HD, sized it up, dug and poured the pit, then went back and bought the pump - the hole was too small (although I made it work, I wish it was much deeper). I also bought a very small pump - didn't think I'd ever have the volume of water to need the 'superior' pump at twice the price.
Just my thoughts - I'm sure some real experts will weigh in soon.
Whether a simple sump, not connected to any weeping tile, will work or not depends on the sort of soil in the area and whether there's any sand/gravel under your slab. Worst case it will only drain about a 5-foot radius.
Based on your description of the problem, it may be that tending to grading around the house may be the best approach. If you can prevent standing water within about 10 feet of the foundation then you'll usually be OK.
Install downspout extensions so that water is dumped at least 5 feet from the foundation. (Don't try to run the downspouts through buried pipes -- they always clog.)
Pay particular attention to any driveway/sidewalk/patio slabs that abut the foundation -- if they slant at all towards the foundation they can cause big trouble. This turned out to be the big deal with our house -- getting the driveway slab mud-jacked solved a problem similar to yours.