Need some DEEP French Drains, how can I do this or hire someone?

[mancho]

Hi!

I'm new here, and while I don't actually own a Tractor (I would love to if the HOA would let me keep it!), I do need some expertise opinions from you guys and gals.

I have a 1/3 acre property where the house is actually below a slight grade hill, and I get water run off into my property. This is bad, especially on the clay soils in our neighborhood. (this is one of those crazy water district developments where we have no real city acquisition)... anyway, my house is about 4" off kilter, yes WAYYY OFF. This causes problems! LOL

My neighbor is getting lots of movement (we have a ton) in their house and just hired an engineering firm to tell the landscaping company what to do:

- DIG a 9 FOOT french drain ALL THE WAY around the property RIGHT at the foundation.

This is extreme french draining! Any guesses to what the costs? It's north of 25K. ouch.

I think I can hire a company to do this or a bunch of low cost labor to dig it out, but I'm unsure of some details. I will hire an engineer to tell me, but I suspect its going to be the same prescription as my neighbor.

Any suggestions on equipment that could do this? I might need a small front loader to move the "massive" amount of dirt that would need to be removed.. and filled with pebble/river rock for the french drain. You can imagine it's going to be more than a few yards of material.

Anyway, I would love any feedback you folks could provide... I'm near 121 and Josey lane... land of the clay!

 

[Storm56]

Unless you have experience at this I would leave this to the pro's. You can damage the walls digging, one good bump with a big machine and you have a cracked wall that will cost many thousands more to fix. Same with the backfill, too much pressure at one point and guess what? There are reasons why this is an expensive venture.

 

[mancho]

Unless you have experience at this I would leave this to the pro's. You can damage the walls digging, one good bump with a big machine and you have a cracked wall that will cost many thousands more to fix. Same with the backfill, too much pressure at one point and guess what? There are reasons why this is an expensive venture.

Hmmm, while I agree a big machine might wack the foundation... and that can't be good for anyone, I have not considered back pressure.

Specifically if the backfill isn't ... er, what? Right weight? If I'm removing heavy clay and putting back river rock and just a half a foot of sod/dirt, what additional pressure is achieved?

Sorry I'm not fully understanding. While I have machine dug my own patios, hot tubs, etc, this might be a manual project.

I am just thinking this is a simpler project than 25K. I think the labor is no more than 20% of that fee... If I use unskilled labor to dig and the material costs are 60%....

Maybe I'm way off base. But I got a lot of foundation to dig.

Thanks for the input!!! Much appreciated.

 

[Storm56]

Backfill may seem like the easy part, but not always. You must fill slow and even. How about that big rock you did not see and it goes cracking into the wall. Or how about the ground gives way and the machine crashes into the home. A couple of the reasons for the big bucks is the risk of this kind of operation. More than 1 contractor would not backfill without building a brace system inside the basement, another reason for the price. Plus if something goes wrong he will have to ante up for the repair.

Not saying you cannot do it, but it seems like if you knew all the angles you would not be asking questions in a forum such as this. There are jobs better left to a pro. Sometimes cheap is not always the best route. In this type of job, remember, SLOW is FAST.

 

[mancho]

Backfill may seem like the easy part, but not always. You must fill slow and even. How about that big rock you did not see and it goes cracking into the wall. Or how about the ground gives way and the machine crashes into the home. A couple of the reasons for the big bucks is the risk of this kind of operation. More than 1 contractor would not backfill without building a brace system inside the basement, another reason for the price. Plus if something goes wrong he will have to ante up for the repair.

Not saying you cannot do it, but it seems like if you knew all the angles you would not be asking questions in a forum such as this. There are jobs better left to a pro. Sometimes cheap is not always the best route. In this type of job, remember, SLOW is FAST.

Ahhh yes, you are right, I certainly don't have all the answers. BUT, we're in Texas, hence no basements. So I'm only fighting clay on clay. This concern of crashing into a wall, would be ABOVE FOUNDATION. I got 3 feet of foundation concrete (on the outside) but nothing but clay below. So the idea of a retaining wall isn't really necessary.

I hear you loud and clear on pros. Here is the thing. They are WAY over charging for the labor. IF you hire a guy for $10 an hour and work him a week but charge the customer 480% of that. Who's stupid? I can hire that same unskilled labor to dig dirt.

Certainly there are many other concerns, liability, insurance, etc. I'm just thinking this out loud right now.

 

[Storm56]

Ah - was thinking this is a job on a home with a basement. There I go thinking again!

 

[mancho]

Ah - was thinking this is a job on a home with a basement. There I go thinking again!

Naaawww you're good. I should of stated there is no basement, but then again, I never think of basements until I visit the wife's home state: Nebraska. Basements abound.

For some reason, Texans decided it was safer to have a "stand alone" tornado shelter than a basement... heh, must of been the builder that was trying to make more $.

 

[Storm56]

Well then, how about renting an excavator and digging the trench say 4-5 feet away from the home? A lot less chance for something to go wrong there. Fill the trench with stone to about a foot from the surface. Have to figure out something to do with all that dirt though.

 

[BruceWard]

Personally I have difficulty understanding how a french drain is going to stop a sinking house from sinking?

How old is the house? Is this a new problem?

 

[inveresk]

I agree with BruceWard. Your engineer's solution strikes me as a very unusual one and it's fraught with problems.

I don't know how near you are to your uphill boundary but first step in my view would be to form a swale or french drain on or near your boundary to conduct the surface water coming onto your property around your house. This would leave you to deal with only the water falling between your house and your boundary. On a 1/3 acre property, that can't be very far.

If necessary, you could conduct the best part of that remaining surface water away from the house with a second french drain a few feet away from your foundation. You might also consider hard paving between your house wall and the nearest french drain to reduce surface porosity, making sure the fall of the paving is away from the house.

There are a number of geotechnical engineering forums for professionals on the web. Try posting a query in one of those and see what the general responses are. This might give you a clue as to whether you ought to seek a formal second opinion.