HELP -need foundation drainage

[Gordon Gould]

My son wants to put in about 100 feet of drainage at the base of his concrete foundation on a 50 year old house. The footings are down 7 or 8 feet.
He thinks that if we rent a back hoe or small excavator we will be all set.
I told him I thought it would be very difficult trying to dig a ditch
along the foundation. We would end up with a huge hole and mountains of dirt and still not be at the footings.
BUT, I dont know a thing about ditch digging. My machinery experiance is pretty much limited to logging and road maintainance.
Are there techniques and equipment that allow one to do this or
should I try to convince him not to even try at the expence of being just a
pessimistic old man.

 

[Opti-Mist]

An experienced operator could dig a narrow, but wide enough, trench around the house with a standard backhoe of adequate reach. I would not consider this something for an inexperienced operator as it is far too easy to smash the house, causing more repair expense. Of course the usual precautions regarding water, gas and electric lines.

 

[KubotaSam]

My neighbor did exactly this a few years back. He borrowed a full size backhoe from his dad and dug around the perimeter of his house. He put the black drainage pipe is crushed stone, then backfilled. His water problem was gone. Go for it just go slow and careful.

 

[Dmace]

If you do rent, get a mini-excavator instead of a backhoe. With the backhoe you will be constantly moving and setting up plus the outriggers stick out so much it is very difficult to get close to the foundation. With a mini-excavator you can move as you go very easily without setting any outriggers, two pivot points to swing as opposed to one on a backhoe so you can get closer, and they typically have a much better reach and are more powerful per pound then a backhoe.

Keep the rpms low so the controls aren't too touchy and make sure you leave yourself plenty of time. My local Taylor Rental has a Yanmar Vio-27 with a trailer for a 3-day weekend (24 engine hours) for $300.

I used it to pull some stumps my tractor couldn't. It is so much faster and stonger, you can tell it was made for digging.


Click thumbnail for larger image

 

[Botabill]

Get a mini excavator with enough reach to go the depth you need. It'll out dig an excavator hands down. You also need to have someplace to drain the water to or you'll need to have a pump to take the water away from the foundation. Have fun.

 

[laen64]

Bota Bill means the Excavator will out dig the Back-Hoe. I"m with you as well. I learn so much, Thanks to all.

 

[Egon]

My son wants to put in about 100 feet of drainage at the base of his concrete foundation on a 50 year old house. The footings are down 7 or 8 feet.
He thinks that if we rent a back hoe or small excavator we will be all set.
I told him I thought it would be very difficult trying to dig a ditch
along the foundation. We would end up with a huge hole and mountains of dirt and still not be at the footings.

Why does the new drainage have to be at the base of the existing foundation. Could it not be back a few feet, maybe even a little deeper and still do the same/better job.

This may??? allow a bigger faster digging machine access to the area. You would not be in danger of affecting the load bearing area under the foundation. The larger machine has more reach so the spill pile can be farther away. It may also allow a trench to be dug which does not require shoring. Smaller machines may not have the reach for this.

When doing jobs of this sort where collateral damage could be significant it is sometimes best to have proficient personnel at the controls and perhaps even looking after the job.

Questions to ponder:
Have all utilities lines been located?
Will the trench impact neighbouring parties?
How will the new drainage be designed and where will it drain to?
What is the site location like and how much water will be expected to be drained?
How stable and uniform is the soil in the area in question?
How familiar are you with Trench Cave Ins? At eight feet a trench should be shored or dug in such a fashion so that shoring is not required. This may be the important question.

One more question: If the the water is drained and diverted will the foundation footings dry, shrink and cause settling problems?

 

[Gordon Gould]

Thanks for all the advise. We have used a mini excavator before on a wall
project. I had not thought about a way to get the water out of the hole.
Sounds like we should start the ditch where the pipe comes to day light.
Other than the risk of damaging the house or foundation I am starting to
feel better about doing it.

 

[Gordon Gould]

I just saw your reply, egon, after I posted my last one. All very good questions that only experience and knowledge can answer - which we dont have.
His problem arises from the fact that he lives on a terraced steep side hill.
I was wondering if a curtin drain away from the house would work.

 

[Botabill]

A word of caution on trenches. Don't go into one if it is over 4 feet deep. I've seen what looked like a solid trench just collapse for no reason. If a person was in the trench at the time it would have been fatal.