French Drain?

[karoc]

Guys if I build my pole barn in the direction that I want which is on small slope the length will be parallel with the slope. I am kinda worried about water build up on that side. So I was wondering what are the opitions for getting the rain water on other side of bldg to go with the flow of the land. Any ideals on french drain or other choices?

 

[like2wheel]

Guys if I build my pole barn in the direction that I want which is on small slope the length will be parallel with the slope. I am kinda worried about water build up on that side. So I was wondering what are the opitions for getting the rain water on other side of bldg to go with the flow of the land. Any ideals on french drain or other choices?

I had a similar situation & just cut a swale to divert any water heading towards the building.

 

[glentre]

A French Drain in my area refers to a hole in the ground filled with rocks which contains the runoff water until it can seep into the surrounding ground. I think you would want to divert the water around the structure rather than having it seep into the ground on the high side. A very heavy downpour will fill the French Drain and might be a problem getting under your slab. Keep the water away from the building before it gets close to it.

Glen

 

[Bondo]

I had a similar situation & just cut a swale to divert any water heading towards the building.

Ayuh,..... A swale across the hillside to move the water away,....

Get some grass growin' in it, 'n it's maintenance free,.....

 

[harley jim]

I had the same concern when building an addition onto my shop. My solution was to place a 4" perforated plastic drainage pipe along the high side and trenched down both ends to the low side where they drain to the yard. On the high side I almost filled the trench with 1" stone and then I put some road fabric down and about 12" of soil on top to finish.
The corrugated pipe also had a sock on it.

Sent from my SM-A102U using The Garage Journal mobile app

 

[theoldwizard1]

A French Drain in my area refers to a hole in the ground filled with rocks which contains the runoff water until it can seep into the surrounding ground.

That is just a dry well.

Read this My French Drain and Dry Well Project

 

[pmiranda]

If you have room, just grade a swale next to the building. I had planned on needing a french drain but now that the building is done there hasn't been any drainage issue so I"ll wait and see.

 

[Jackfre]

Also, run some channels under the slab to relieve and water build up on the grade side. Also run the French drain. I dug up the end of my house and had a FD installed. The operator used sch 10 pvc per fed drain line. Worked great for 5 yrs and the light plastic collapsed and the ship began taking water again. I dug it out again and used sch 40 pipe and drilled the holes. Worked great

 

[K'ledgeBldr]

A raised building pad for the building- and water will flow around the pad.

 

[Kaizen]

Consider ground drains and gutters to not make it worse

 

[laser3kw]

Mine was built with a combination of above mentioned solutions. I have an above grade slab with a stem wall on the uphill side, the base material was laid to promote under slab drainage. I cut a swale (I learned a new word here) along the stem wall side to promote drainage away from the building. If the OP has the time and ambition, I would add a French drain in the areas he is worried about. That will help all around in the future.

 

[Bretny]

I had a similar situation & just cut a swale to divert any water heading towards the building.

Swale up on the hill would be my first line of defense. Then french drain to daylight. Dosnt even have to be deep. Just under the concrete underlayment. While your doing this you should pur provisions in for gutter drains to daylight too.

 

[MeentSS02]

The effectiveness of a french drain is heavily dependent on soil type. Around here, we have a ton of clay, and it is not ideal for a french drain...water takes forever to absorb.

Whoever did the downspout drains around my house didn't understand a few things: soil conditions, proper drain sizing, and material selection. They made a lot of french drains, and all of them ended up failing for the same reasons within about 10 years or so, which led to water backing up and spilling over against my house/foundation. Every single one of them was done with 3" corrugated, which could not flow enough to handle the heavier rains. All of them ended up with root infiltration - since they were done with corrugated, you couldn't just clean them out, so all of them had to be dug up.

I was going to replace them all until I did some experimentation with one of the downspout drains. I attempted to do another french drain using 4" PVC, and quickly found that the soil just isn't conducive to it. Due to this, I just decided to divert the water away from the house (to daylight), and let it spread out at surface level into the ground. It isn't ideal, but with how my property lies, I don't have enough slope to drain it toward a storm drain without installing a pump of some sort.

Bottom line: don't put too much thought into it...just divert the water to where it isn't going to cause harm, and let nature take care of the rest. Bonus points if you can do it in a way that doesn't cause standing water. I'm not a fan of french drains, at least not around here.

 

[theoldwizard1]

The effectiveness of a french drain is heavily dependent on soil type. Around here, we have a ton of clay, and it is not ideal for a french drain...water takes forever to absorb.

There is a difference between a French drain and a dry well.

The French drain just allows an easy path for the water to to flow through to get to a lower point. It works fine in clay, because most of the clay is removed and replace by gravel and a pipe. If it goes to daylight (best solution) a dry well is not needed.

Whoever did the downspout drains around my house didn't understand a few things: soil conditions, proper drain sizing, and material selection. They made a lot of french drains, and all of them ended up failing for the same reasons within about 10 years or so, which led to water backing up and spilling over against my house/foundation. Every single one of them was done with 3" corrugated, which could not flow enough to handle the heavier rains. All of them ended up with root infiltration - since they were done with corrugated, you couldn't just clean them out, so all of them had to be dug up.

I was going to replace them all until I did some experimentation with one of the downspout drains. I attempted to do another french drain using 4" PVC, and quickly found that the soil just isn't conducive to it.

Soil condition has very little to do with a properly designed and installed French drain. The trench need to be deep enough (2'-3') lined with geotextile (this help prevent roots and silt infiltration), laid on a bed of gravel (for pitch adjustment), solid, non-corrugated pipe with a sock, covered with more gravel and geotextile. You can place 6"-12" of top soil above this, but for faster drainage you want gravel all the way to the surface.

 

[MeentSS02]

There is a difference between a French drain and a dry well.

The French drain just allows an easy path for the water to to flow through to get to a lower point. It works fine in clay, because most of the clay is removed and replace by gravel and a pipe. If it goes to daylight (best solution) a dry well is not needed.

Read my original thread.

I lump the two together...in my mind, both operate under the assumption that the ground is going to absorb the excess water. That's all fine, but all you are doing is adding water to an area that already has to absorb the normal amount of runoff from rain. Once the soil has absorbed all the water it can, that's it. It doesn't matter how much gravel you add...it still has to be absorbed by the soil around it, or it's going to eventually come to the surface. I guess you can at least choose where that is though, which is the point...not next to your house being preferred.

I did read your thread, and by my read of it, you reached the same conclusion that I did, but I didn't have to do any of the digging. The fact that you have to pump the excess water from your dry well somewhere else tells me that it isn't a 100% solution. Yes, it's going to depend on the time of year, but I don't have any areas of my yard that can tolerate any more moisture in the spring than they already get, which is when all of my problems occur. No french drain or dry well is going to solve my problems, and it's because the soil can only accept the water at a set rate, and that rate is low for clay.

 

[Bretny]

Not quite. A french drain collect water into a pipe to run to another area. A drywell absorbs water well its suposto. Any area with clay and you can kiss a drywell good bye.

 

[MeentSS02]

Not quite. A french drain collect water into a pipe to run to another area. A drywell absorbs water well its suposto. Any area with clay and you can kiss a drywell good bye.

I guess I'm getting confused on the terminology. It goes like this in my head:

Underground Drain - collects water (like from a downspout) and directs it to another area, done with solid pipe. No gravel or fabric needed to keep root infiltration or silt at bay. Could go to daylight, could transition to a french drain, could go to a dry well.

French Drain - collects water and directs it to another area, but uses perforated pipe with fabric and rocks around it that allow the water to slowly seep in to the surrounding soil while it's on its way to its final destination (daylight or a dry well).

Dry Well - a large underground something (using something like an NDS plastic tank or just a large pit lined with fabric and filled with gravel) that gives a place for the water to collect until it can seep into the surrounding soil.

Where the french drain and dry well concepts fall apart for me is that you can't wall them off to keep the surrounding soil from dumping into them once the ground is fully saturated. If they only collected the runoff from the source you cared about, it would be ideal, but all you are effectively doing is adding more water to some area that hopefully doesn't have too much already.

 

[strutaeng]

Avoid "french drains" if you live in Houston. It's all fat clays down there and will eventually cause the pipe to clog. If you want to do sub-surface drainage just use smooth wall pipe with catch basins. They are very easy to keep clean and the water flow would be superior to french drain, even more so in a few years as the filter fabric gets clogged by soils fines, roots, debris, etc.

I mean, french drain sounds cool and all because it has the word "French," but they just don't work well in areas with clays that receive a ton of rainfall. Whatever size you think you need for the pipe, go one size up. That will probably handle the next Harvey.

Most of the french drains I see are at least 1/4 to 1/2 filled with dirt.

 

[karoc]

Guys thanks for all the ideals this is fantastic and I learned little about what I did not know. Na the soil is sandy and up around the Toledo Bend area,lots of sand. So I just don't want lot of water to get under slab so will be installing some gutters and have them pipe to lower side of my place. So once I get going I will come back to this post and go over the ideals and see what fits my situation. Thanks again

 

[theoldwizard1]

Not quite. A french drain collect water into a pipe to run to another area. A drywell absorbs water well its suposto. Any area with clay and you can kiss a drywell good bye.

Not entirely ! Yes, the water collects in my dry well and if it comes in too fast it will overflow. All dy wells need an over flow, unfortunately mine is just the surface.

The key to a GOOD dry well is making is large enough for most heavy rain situations !

View media item 55496
IIRC correctly, that dry well is 8' diameter and about 6' deep. The gravel comes up to about 1' below the grass. Plenty of room to store water. The real bonus is all of the surface area on the side of that pit that lets the water move into the sub-soil. As I mention in the original post, it would take days and days for the water on the surface to sink in, even when I drained as much surface as I could. Now, you can walk on it 24 hours after a heavy storm that had water up to the surface.

 

[theoldwizard1]

Avoid "french drains" if you live in Houston. It's all fat clays down there and will eventually cause the pipe to clog.
.
.
Most of the french drains I see are at least 1/4 to 1/2 filled with dirt.

Use smooth pipe and HD geotextile on the bottom, sides and top. At least 1' of gravel on the sides and top. Put a sock on the perforated pipe.

The real key to any French drain is having some place for the water to go to ! Dry well is NOT the best solution.