Has anyone had an exterior French drain installed?

If so, who did it?  How much?  Good/bad/ugly?

Yes.  Avellino.  It was only one area so 800. Not ugly.

What is an exterior French drain? As opposed to the kind they put inside the basement?

bluepool said:

What is an exterior French drain? As opposed to the kind they put inside the basement?

Yes   

bluepool said:

What is an exterior French drain? As opposed to the kind they put inside the basement?

An exterior French drain is a trench filled with gravel, typically with a 4" diameter pipe at the bottom with holes in it.  The surface water hits the gravel-filled trench and filters down to the pipe. The pipe collects the water and drains it to an outlet.  If there it slope or pitch, that outlet can be daylight. Otherwise it might be a dry well.

a dry well is a big pit filled with gravel that fills with water and disperses the water to the ground.

jimmurphy said:

a dry well is a big pit filled with gravel that fills with water and disperses the water to the ground.

How big is a typical dry well? 20 gals? 50 gals?

BTW, an exterior french drain installation is a DIY project.  You don't need special equipment, and all the material is available at HD and landscape supply companies (like Boychuck or Orange Garden Supply).

xavier67 said:

jimmurphy said:

a dry well is a big pit filled with gravel that fills with water and disperses the water to the ground.

How big is a typical dry well? 20 gals? 50 gals?

Depends. Here's an article: 

https://www.thenaturalhome.com/drywellinstallation.htm

While its a DIY, I think the level of difficulty would come from your access to the foundation or whether there are shrubs, [foundation plantings] that would limit or restrict digging down far enough to be effective. Seems that a proper foundation drain is installed at the base of the wall which in some homes could be a good 6' down or more and running that pipe to a drywell would mean that the drywell would have to be even deeper allowing for a minimum 1/4"/ft pitch.Unless you are at the top of a hill ,whereas you wouldn't have the problem in the first place,that would prove impossible.Especially where it calls for the drywell overflow to run to daylight. I have heard of creating a "ground-roof" whereby you excavate along the foundation approx 2' deep and apply a rubber membane to the foundation using a waterproof material and fold the membrane 90 degrees away from house, with a slight pitch, and then backfill which in theory would direct water away from house/bsmt. Problem is its also pretty labor intensive and while it should work, you wouldn't know till the first gully washer and if it didn't, would be disheartening.Retrofits always suck.

I assumed the OP's question was related to runoff from the roof/gutters or to re-direct runoff from adjacent properties.

I assumed,and probably incorrectly,that the OP was trying to mitigate intrusion into the bsmt. No harm, no foul.

Georgieboy,

I would never tackle the kind of drain system you are describing.  I may have misunderstood the OP but I was referring to something like this that would deal with surface water and thus digging down 6-8".

ETA: Sorry didn't see your post.

Seems we have a definition issue here.

 I assumed that the OP was trying to catch water before it approached the house, which is the function of a French drain.

A French drain does not capture downspouts. A French drain also does not serve as a foundation drain.

A dry well, on the other hand, can capture rain from any of the above-mentioned water-gathering elements.

Why not tie it into the existing sump discharge? Assuming it drains to the storm sewer.

Who said he had a sump discharge? Or even a sump?

We had drainage installed in our backyard several years ago. The contractor recommended burying the perforated pipe and covering it with fabric. So there is a trench filled with partially with gravel then the fabric is placed inside the trench and the pipe placed on top of the fabric. Then fabric is wrapped around the pipe and it is covered with more gravel. Then the top is filled (or not) with soil.

My contractor did not bury the pipe deep enough so the grass has remained non-existent to this day. But the final result has been a good one in that the drainage works very well. I estimate he did about 400 feet of drainage which ultimately empties underground to a storm drain in the street.

ETA: The fabric is a big part of this because it keeps the small pieces of rock and debris from getting into the drain pipe and clogging it. 

Right on. I would probably call it a trench type drain to differentiate between what is commonly called a french drain when talking of basements or a foundation drain which is typically installed during construction.Main thing to remember is any water you capture must have a place to go and not adversely impact adjoining properties.

jimmurphy said:

Seems we have a definition issue here.

 I assumed that the OP was trying to catch water before it approached the house, which is the function of a French drain.

A French drain does not capture downspouts. A French drain also does not serve as a foundation drain.

A dry well, on the other hand, can capture rain from any of the above-mentioned water-gathering elements.

RobB said:

Why not tie it into the existing sump discharge? Assuming it drains to the storm sewer.

It is somewhat town specific but there are many new regulations that do not allow any net increase of discharge to storm sewers (with preexisting amounts grandfathered). That is why some kind of catchment system is increasingly required. The statists want water discharge kept on property as much as possible

bramzzoinks said:

RobB said:

Why not tie it into the existing sump discharge? Assuming it drains to the storm sewer.

It is somewhat town specific but there are many new regulations that do not allow any net increase of discharge to storm sewers (with preexisting amounts grandfathered). That is why some kind of catchment system is increasingly required. The statists want water discharge kept on property as much as possible ">

Actually, the statists want everyone to bear the burdens of their own property rather than have the collective carry the load.

I admit that I have a vested interest in this issue. I live on one of Maplewood's many sloped streets, the water I would like to divert from my property is not solely water that falls on my property. The runoff from uphill property owners can be torrential. If the statist want everyone to be responsible for the mitigation of water that falls on their own property I'm all in favor. I'd just like the statist to start at the the top of the hill.

I'm the OP and the problem is a small amount of water, coming from the base of the cinder blocks, on one wall, but only after a very hard rain.  I'm at the top of a hill but water does tend to accumulate in between my house and my neighbor's.  I'm hoping to avoid a sump pump, interior French drain.  In my naive assessment, a sump pump would never have enough water to pump.  When I get water, it's never more than a gallon from two or three spots on the wall.  Probably more like a quart.

are you wanting this ? looks like just as much work as interior french drain-- but i guess if you have a finished basement and dont want to tear it up its an option 

https://www.youtube.com/watch?v=Sp5sT1JITa8

Wow! Quite intrusive and no doubt costly.First thing I noticed was they had no protection from trench collapse. Time is money I guess.

Well this is reassuring.  I think I can do this myself.  Not.

Actually, my image of it was a foot wide trench, dug down a foot, with some sort of conduit out to the back yard or street.  Not the creation of a bullet proof moat!

new207040 said:

are you wanting this ? looks like just as much work as interior french drain-- but i guess if you have a finished basement and dont want to tear it up its an option 

Before you get your mind set on "I want to solve this problem by doing X" you may want to have someone (or several someones) out to take a look. Maybe a french drain is good but regrading would be better. My own personal water issues were solved by knocking the mortar out from between two bricks the previous owner had installed around the back walkway. Water was pooling and flowing back toward the house. Knocked out the mortar, walkway drained to the driveway, no issues since.

Sealing is not always the best option. Water will find its way around to another spot and then you could have a bigger problem.

Diverting the water seems to be what the OP is after in this case. I am interested in this topic, too, because our new house gets dampness coming through the walls in the unfinished side of the basement. Which worries me, because of the side of the basement that is sheetrocked, so I have no idea what is going on behind the drywall. 

I have been considering attempting some grading on the outside to keep the water flowing away from the house, and maybe some minor trench digging with gravel. My first thought was to put in some raised planting beds close to the house on the side that has the trouble, digging down first and laying gravel, then placing raised planting beds on top of that for a kitchen garden. Not sure if it is a sound idea, drainage-wise, but it was my first idea.