Basement Drainage

[molo]

I HAVE TO EXCAVATE THE EXTERIOR Perimiter Foundation Of A House> It Is Very Long> If I Go To The Same Height (an Inch Below The Top Of The Footer) Along The Length Of The House I Will Have A Level Trench> Is This How Its Done> Im Wondering How The Water Will Flow Out>

Excuse The Typing> A Popsicle Melted On The Keyboard

Tia
Molo

[markts30]

1. How deep is the excavation going to be? 1-2'? 3-4'? over4'?
This is important because of the labor involved and the risk of trench collapse after/during excavation....
2. Do you have a basement sump for groundwater? If so, can you tie into it easily (minimal concrete cutting/breaking)?
3. Is there natural drainage (ie a slope you could "daylight" the drainage pipe to so the water will flow away from the structure?
4. Are you familiar with drainage piping/"weeping tile" installation?

Lots of things depend on the type of structure, availability of sumps and pumps, depth of the footing, slope/natural drainage of the land and ability of the worker...

[molo]

Hello<
Thanks For The Response Markts

!> One Side Of The House Is Three Feet< The Other Side Is Six Feet To The Footer

Two> There Is No Groundwater Or Water Table Problem Here< It All Comes From Rain Coming Down The Hill< There Is No Existing Sump In The Basement

Three> There Is Definitely Natural Drainage Daylighting Will Be Easy

Four> I Am Familiar With Several Drainage Piping Products> I Just Dont Know What The Best One Is


Tia<
Molo

[jadnashua]

If the dampness in the basement is only coming from the gutters, run them into a drywell and maybe something like a leachfield if you think you'll have that much at any one time. In fact, if you regularly have watering bans and you can afford the space and time, you could run it to a cistern and use it to water the yard and plants.

[molo]

Hi Jadnashua<

The Moisture Is Without A Doubt Not From Gutters> They Are All Well Directed Away From The Building Downscope> The Moisture Is From Rain Surface And Subsurface Runoff That Comes Down The Hill And Hits The Foundation

Molo

[jadnashua]

Two cardinal rules about surface water, drainage around foundations: You need the ground around the building to be graded away from the foundation, 6' is sort of the desired minimum, and control significant runoff towards it. That can be done with swales, ditches, or other landscaping features. The simple expedient of running the gutters out away from the foundation, and preventing surface runoff from running to the foundation should alleviate a lot if not all of your problem.

[markts30]

!> One Side Of The House Is Three Feet< The Other Side Is Six Feet To The Footer

This comment would make me suggest you look at a landscaping solution as was already mentioned...
It will be a lot cheaper and safer...
Any excavation as deep as the one side of your house would require either shoring or sloping the sides...
this would result is lots of $$$ and time...
Your best bet is the landscaping route...
If you choose to do the foundation drain, please hire a pro to at least come and advise you before you start, and, if you decide not to shore/slope the trench, make sure your life insurance does not have a stupidity clause...LOL

[Old Dog]

If you choose to do the foundation drain, please hire a pro to at least come and advise you before you start, and, if you decide not to shore/slope the trench, make sure your life insurance does not have a stupidity clause...LOL

Thanks alot! I'm still cleaning up the coffee I just sprayed all over my screen!!

[molo]

http://www.youtube.com/watch?v=blt9JsDNVgw

LOOK AT THE BOTTOM OF THE WALL< THERE IS A FAUCET COMEING OUT THE CONCRETE BLOCK THAT I DRILLED A HOLE IN THIS MORNING> I DRILLED A `1/4" INCH HOLE IN A FEW BLOCKS THAT WERE WET AND LOOK WHAT HAPPENED

[jimbo]

I am not a builder...but I have this question: Is there an issue with excavating that deep on the outside of the foundation wall? In other words, is the fill supporting the wall, to where bowing or something could occur? Just asking. We don't have basements or foundation walls like that....everything is on a slab!

[Mr_Pike]

You don't have to install a drain tile completely around the perimeter of the home.

All you have to do is create a depression in the water table by either installing one or more sump pits in your basement for the water to collect in, or by installing one or more dewatering wells on the outside of your home.

I would assume will be far simpler to do these two things, than to dig around the entire exterior of your homes foundation.

Go three feet deeper than your basement floor, surround your casing with rock or gravel, insert pump on a float switch. Plug in.

[Old Dog]

I am not a builder...but I have this question: Is there an issue with excavating that deep on the outside of the foundation wall? In other words, is the fill supporting the wall, to where bowing or something could occur? Just asking. We don't have basements or foundation walls like that....everything is on a slab!

The fill isn't supporting the wall as you are thinking it might.One of the reasons you backfill a wall is to be able to slope away from the building for water drainage.Without it water can erode the ground around your foundation weakening it causing cracks and other unpleasant problems.It also is for leveling the ground around a building for landscaping/walkway purposes...
The issue that was being discussed was a safety issue.A 6 foot trench not properly shored up can collapse in on you burying workers/yourself.Not a pleasant way to go,being buried alive.

I'm not sure how old this house is but normally you waterproof the foundation before you backfill the walls to keep water out.The correct membrane
thickness is the key to success and using a fibre board to protect the membrane from damage during backfilling is important.
Other poster have him on the right track with drain pipe,sloping,ect...

He may still see dampness in his basement even doing all of this if walls are not waterproofed.
Hope I answered your questions...

[Old Dog]

http://www.youtube.com/watch?v=blt9JsDNVgw

LOOK AT THE BOTTOM OF THE WALL< THERE IS A FAUCET COMEING OUT THE CONCRETE BLOCK THAT I DRILLED A HOLE IN THIS MORNING> I DRILLED A `1/4" INCH HOLE IN A FEW BLOCKS THAT WERE WET AND LOOK WHAT HAPPENED

I don't envy the problem that your having! Definitely need to get that water away from the house.Don't let anyone try to talk you into sealing the inside of the basement wall either.The goal is to keep the water out of the wall,not let in partway and stop it.
I left a post earlier here about your problem with another poster...I presume the foundation walls haven't been waterproofed or if they were the membrane has failed.
Trenching the walls and waterproofing would be how I would do it,along with drain pipes,possibly yard drains,gutter downspouts all connected to drain away from the house along with the ground sloped min.6-8 feet away.
Just have to make sure the water isn't going to be a problem for a neighbor down the hill from you...(legal issues can be a drag!)
The 6 foot wall,I'd hire a reputable co. to trench that for you.The membrane you can apply yourself,correct thickness is key,along with protecting the membrane when you backfill.
You could probably do what other posters have said,alot of good advice has been given...IMHO,only way to get the dampness out is with properly waterproofed walls...

[toolaholic]

FIRST off_ What a pig pen! There's too much to discuss Here!
Suggest You go to cont. talk forum. click on excavating forum. ,We have many posts on this. We work under Geo. Techs. plans on a lot of this. If You're in the bay area I'll stop by to guide. Also have backhoe and dump truck. Good luck

[molo]

Two cardinal rules about surface water, drainage around foundations: You need the ground around the building to be graded away from the foundation, 6' is sort of the desired minimum, and control significant runoff towards it. That can be done with swales, ditches, or other landscaping features. The simple expedient of running the gutters out away from the foundation, and preventing surface runoff from running to the foundation should alleviate a lot if not all of your problem.

I am curious about what the slope graded away from the building does. I know it helps, but I do wonder about the direction water takes when it does start to saturate the ground... does it go straight down or does it spread out as it goes? If it spreads, it could work it's way over to the foundation, even with proper slope. Also, I, sure the surface affects drainage as well. For example, one side of the house has asphalt driveway right up to the concrete block foundation, yet parts of it slope toward the foundation! The other side of the house has 6" of soil with clay underneath. There is a slope problem here, and although there is clay, the moisture st ill goes down. I guess moisture can work it's way through clay? IF I COULD Resolve this prob without excavation that would be great. I'm just wondering if slope combined with proper gutters will do it?

TIA,
molo