[barbarake]

I'm just full of questions this morning...

My house is on sloping ground. It slopes down to the front of the house and continues sloping down behind the house (down to a dropoff which is the edge of a flood plain). It's a moderate-to-steep slope.

The foundation is cement block (long story, was supposed to have brick facing but the *(%#@ contractor didn't do it). Anyway, the foundation sticks two feet out of the ground at the front of the house and it's about seven feet tall at the back of the house.

The ground will be graded so that there's a dip in front of the house that extends around to the sides. (I'm not sure of the technical term - a 'dip' is not quite as deep as a ditch.) Theoretically this will lead the water around the house.

Question - should I have the 'dip' dug deeper (more like a 'ditch')?? How about putting a perforated pipe and/or gravel in it and covering it with dirt?? Is there stuff that I can put on the outside (or inside) of the concrete block foundation to help prevent any water problems?? (The basement will not really be used for anything but I want to forestall any water problems now rather than later.) Any comments or suggestions would be appreciated...

Thanks.

 

[tkrabec]

how much rain do you normally get in that area
if it's alot then either dig it deaper or make the mound on the house side higher or do both. It's not the normal rain that will get you but the 24 hrs of steady rain, when you are out of town or sound asleep and it was not forcast

-- Tim

 

[retire2$]

barbarake

What you are describing is called a swale. The wider and shallower you make the swale the better. Water will run in and be diverted around the house as you stated. Most swales are just planted in grass. Because the swale is not deep you can mow safely. You may want to call your soil conservationalist or a grading contractor for ideas.

 

[agmantoo]

A grassed waterway is what you need to construct. At this site you can see how one is constructed
www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex795/$file/573-6.pdf?OpenElement

 

[janesworld99]

i like to "control" water flow with a burm instead of a dip the burm would be the opposite - dirt piled up to keep the water from going any farther. It is good that your house is on a slope, as long as you direct the water away from the house. Picture it like this: You are in the house looking toward the top of the hill. Your burm would be shaped like an upside down V with the point being centered (middle of house). When the water runs down the hill it comes to the point and then runs off to the sides of the house instead of directly to the house. Hell i i know if you understand what i just wrote - ha....... peace & love,,,,,,,, jane

 

[rambler]

I would be worried if you were closer to the bottom of your slope that to the top. I think your swale that is planned will control the surface water just fine, I would do that as planned.

The problem with building on a hillside is the underground water flow. I farm rolling hills, and am very familiar with this. My worst wet spots where I get stuck badly are the sidehills, not the valley bottoms.

The water soaks into the ground, and then flows along looking for the water table. Many times there are different layers of ground in your soil structure, and the water will either hit a sand/gravel layer & flow rapidly in that layer down the hill; or it will hit a clay layer it can't get through, and flow slowly in whatever is above the clay layer. (In my fields, I can tell you where these undergound soil layers come out, as that is where the everlasting weeping wet spots are - water soaks into the ground at the top of the hill, flows along soil lines, and comes back out of the hill where these soil lines surface or are deeply disturbed.)

So, you made a big hole, disturbed all these soil layers, and put in a block basement hole.

Now the water comes along it's layer, and hits the block. It will try to soak down the wall to the bottom and go under the house. Or into any crack or pore it can. Or it might find a dry soft layer of something under your house, and use that to drain a lot of water either farther down the hill, or up into cracks in your basement floor.

All of these issues _should_ have been addressed by your builder, with a tile around the bottom of your house (several feet away) at basement floor level, with an out-drain somewhere down the hill. Your foundation should be sealed somehow - tar or special clay or etc. - and gravel should be over the tile to allow any water coming down the hill to drain through vertically to the tile rather than pushing against your wall.

Along with your swale, your basement will stay VERY dry in your conditions with this drain tile.

Without that deep perimeter tile & special backfilling/sealing, you could have many problems. Of course, in the right soil & rainfall conditions, you might not have any problems at all - I don't wish to falsely alarm you.

Just, it costs so very little to add that tile when the foundation is dug, and it costs so very much to redig & install it - I sure hope they put it in for you.

--->Paul

 

[barbarake]

SWALE!! That's the word - I couldn't come up with it to save my life!!

I should explain a bit more. The concrete footing is not very deep. It passes code and everything but it's only maybe a foot deep into the soil. The concrete block foundation starts at ground level and goes up. It's two feet high in front and seven feet high in back.

The final grading has not been done yet. Right now there's a natural 'swale' in front of the house. When the final grading is done, dirt will be brought in to contour the land however I want it. I can turn the 'swale' into a 'ditch' by adding some dirt between it and the house - but this would mean that part of the concrete block foundation would have dirt against it. Or I could add more dirt to form a 'berm'.

The 'basement' is nothing fancy - it's just the open space under the house formed by the house being on a slope. Just a dirt floor and concrete block walls (the foundation).

 

[rambler]

Well, now, you can't have a basement with a 1' footing with 2' of blocks on top of it, so I don't understand what you have! That's a crawl space.

Here in MN we need to go more than 4' to get below frost for the footing, so nearly all houses have a real basement.

As I understand yours, you just have a dirt slope under your house, 2' from the floor on the high side, and 6' from floor on the low side? With 1' of concrete in the dirt for a foundation.

Couldn't build anything like that in my climate, wpu;d be way too unstable from frost & water pressure so I'm not much help.

--->Paul

 

[barbarake]

Rambler - I totally understand. I grew up in Upstate New York where all the houses had full basements. And the only other footing I've seen here in SC was one we did ourselves. Did it with a backhoe - 3 feet wide and 3-4 feet deep. The inspector mentioned that he'd never seen a footing like that and that he bet that there 'was not another house in the county with such a hefty footing'.

But evidently codes around here are much less strict. We do have a very moderate climate compared to much of the country. Literally, the footing only goes a foot into the ground. So it's not like the ground was disturbed much - only a one foot ditch was dug, the footing poured and the concrete block foundation on top of that.

So you're right - the basement is only two feet high at the very front of the house but slopes to seven (maybe eight) feet high in the back. Dirt floor.