need input on water seepage please

I am trying to eliminate seepage rain water from rising over slab on building 1. We have a sump that does fine as long as there is power.I need to fix for no power. I am planning on digging a trench ;( red line) well below slab grade and try to make the water drain out from under building 2. And continue out to a cleanout and fill bed.Any ideas would be great! Thanks

Hi Cliff,

It's tough to give you a really thorough answer without a bit more information.  Is it possible to attach a photo of the problematic area?  Some questions I have for you . . .  What are the conditions when the water is the problem (any rain or heavy rain)?  What's your soil like?  Are there any bodies of water nearby?  What's your building made of?  Is roof runoff part of the problem?  Do you have gutters?

There are two basic paradigms to keep in mind when dealing with water problems: runoff - where does the water flow initially when it initially shows up and seepage - what happens to the water once it soaks into the ground.

Digging your trench may help you once the water is in the ground, but depending on how you build it, it may not help you at all with runoff.  It is generally significantly easier to get your water away from your building before it's in the ground.  I'm not sure how much more I can offer at this point, but if can give me some additional info, I'll be happy to help if I can.

Cheers,
CJ

Remember water goes downhill. That means the trench _must_ go downhill and in order for any water collected by the trench to leave gracefully it must have a way to leave the trench and carry on... DownHill. If the water has no exit (you guessed it) down hill, the trench becomes just a long bathtub, holding water but not draining. So not much  much help in that case.

Finding a way (direction) to drain water away can be difficult sometimes. Diagrams are a good start but like Cj says - lots more info before any answers can apply directly to your particular situation.


Rufus

TO:  Cliff Persick
FROM:  Eric Koperek = erickoperek@gmail.com
SUBJECT:  Building Drainage
DATE:  PM 2:41 Tuesday 20 September 2016
TEXT:

(1)  Following are general rules for building drainage.  These rules have been developed over many centuries of practical experience by European craftsmen.

(2)  Dig a rain trench all the way around your building.  The trench should be at least 1 foot = 12 inches wide.  Dig the trench down to the frost line = 3 to 5 feet deep in most temperate climates.  Center the trench under the eaves of your building roof.

(3)  Fill the trench with cobblestones = round river rocks.  If you can't find cobblestones use river pebbles = small round river rocks.  Round rocks have lots of big holes so water can drain rapidly.  Do NOT use crushed stone to fill trench.  Crushed stone packs tightly so there are few gaps for water to drain.

(4)  Dig a length of trench down slope so your rain trench can drain to lower elevation.  Follow a 2% grade.  Fill drainage trench with cobblestones or river pebbles.

(5)  If you build a good rain trench you will not need roof gutters and down spouts.  No more roof cleaning!  No more gutter maintenance!  No work ever!

(6)  If desired, you can connect your rain trench to a cistern for potable water storage.  Lay 4 to 6 inch diameter ceramic or plastic drain pipe on a 6 inch deep bed of river pebbles.  If possible, wrap drain tile or plastic pipe with geotextile or "drain sleeve" to keep sand, silt, and clay out of drain lines.  Cover drain pipe with 6 inches of river pebbles.  Cover river pebbles with 3 feet of coarse sand.  Cover coarse sand with a 6 inch layer of river pebbles and another 6 inch layer of river cobblestones.  The pebbles and cobblestones protect the sand filter.  Install tile line so it drains with a 2% slope down hill to cistern.  Note:  Size cistern based on roof area and average rainfall.  RULE-OF-THUMB:  1 inch of rain falling on 1 square foot of roof yields 2/3 gallon of water.  Rain rolls off roof, falls into trench, filters through sand, then flows through drains to cistern.  My office water supply comes from a 117 year old rain water filtration trench which has never received any maintenance.  Result:  Pure water and almost zero work.  (Once a year I clean the cistern with a swimming pool vacuum, whether it needs it or not).

(7)  If properly constructed, your rain water filtration trench will operate without attention for hundreds of years.  Water filtered through 3 feet of sand will be clean = potable.  Don't plant trees or shrubs near drain tiles or roots will clog conduits.

(  Carefully examine slopes above building.  Slopes collect lots of rain.  This water has to go somewhere = usually into your foundation or basement!  INTERCEPT WATER BEFORE IT GETS NEAR BUILDING!

(9)  Rent a trenching machine and dig a trench as deep as machinery allows.  Install trench not more than 50 feet up slope from building.  Fill trench with plastic drain pipe (cover with drain sleeve) and cobblestones or river pebbles.  Site trench so that it drains out and away from building.  Lay drainage pipe on a 2% grade down slope.  Note:  If drainage problems are severe you may need to rent a back hoe or excavator and dig trenches 8 or more feet deep to block underground water movement.

(10)  If you have a massive slope above your building you may have to dig additional interception trenches spaced not more than 50 yards apart.  

(11)  If surface water flow is substantial build a drainage swale up slope from building.  Swale should be 8 feet wide x 2 feet deep.  Line swale with 1 foot = 12 inches of rip-rap = orange to grapefruit size stones.  You can use crushed rock to line swales if desired.  Drain swale out and away from building.  Use 2% drainage grade.

(12)  RULE:  Every building should have a drainage trench not less than 1 foot wider than the foundation, and not less than 2 feet deeper than the foundation.  Lay 6 or 8 inch diameter tile to rapidly drain water away from building foundation and walls.  Fill foundation trench with cobblestones or river pebbles for superior drainage.  A properly constructed foundation drainage trench is the last ditch defense against water seepage into basement.

(13)  RULE:  If you dig a hole it will eventually fill with water.  This is basic common sense = widely ignored by architects and contractors.  The old fashioned way to waterproof a basement is 3 coats of tar on the exterior wall + a high capacity drainage system.  Some modern contractors use pond liner.  I prefer to build basement walls out of waterproof concrete because it lasts nearly forever.  My basement is built out of Roman pool concrete = my walls and floors are always dry.

(14)  I grew up in a 400 year old house with an absolutely arid basement 16 feet below grade.  The secret:  Wide foundation trenches and lots of cobblestones.  This is the same technology used to build Middle Age castles and other historic buildings.  Do it right the first time.

(15)  I just finished a drainage contract a few weeks ago.  My esteemed clients built a $350,000 house at the bottom of a nearly 100 acre slope (hay field) and wondered why their basement flooded 4 feet deep.  I charged them an extra $5,000 just for being stupid.

ERIC KOPEREK = erickoperek@gmail.com

end comment

Thanks for all of your inputs...
Here's another pic/.
Yes the problem is from roof run off mainly and also it is uphill on the left side of building 2.
I am planning on putting a 6 inch french drain on the left side(/ see blue line). It is gonna flow the way the arrows show ; and go into an open concrete ditch.This should catch most of the water.The red line is gonna be under the /building.Where the water rises over slab. Another french drain. Its going to continue on out from under building to the right.;;downhill .Then to bed and a /c/leanout.

Eric Koperek  <- What he said!

Cliff, I'm still not 100% sure I understand your diagram, but if you do what Eric is describing, you are certain to solve your problem and prevent any future problems as well!

Eric, thanks VERY much for that description.  I definitely filed that nugget away for later.  You only left me with one question.  What do you do for overflow on the cistern?

Cheers,
CJ

TO:  Cj Thouret
FROM:  Eric Koperek = erickoperek@gmail.com
SUBJECT:  Overflow from Cisterns
DATE:  PM 5:32 Wednesday 21 September 2016
TEXT:

(1)  All cisterns should have an overflow pipe to drain excess water.  The outflow pipe should be the same diameter as the inlet pipe.

(2)  The overflow pipe should be closely screened to prevent entry of insects, birds, rats, and other small animals (including small children).

(3)  Cistern overflow should drain to a lower elevation so that standing water does not remain around cistern.  This is a critically important detail.  

(4)  To keep underground tanks watertight, walls must be kept DRY.  This seems counter-intuitive but this is how cistern technology works.  Pools and cisterns usually fail because of water seepage through the EXTERIOR wall surface.  Thus, it is essential to keep water well away from underground walls.

(5)  I use a surface gutter (made from river pebble concrete) to drain water away from my office cistern.  The gutter leads to a French Drain in my garden.  Other drainage possibilities include underground pipe or tile.  Nota Bene:  You might consider using surface gutters (rather than roof gutters) to dispose runoff from your eaves.  Surface gutters are much easier to clean and maintain.  Most colonial and earlier buildings used surface gutters made from brick or stone because these were cheaper and more convenient.

(6)  Always think BEFORE draining.  Where will the water go?  Don't just dump excess water onto your lawn or you may create a swamp.  If necessary, dig out an area of lawn 1 foot deep and fill with a 1 : 1 mixture = 50% coarse sand + 50% topsoil by volume.  This will make a high-infiltration rate zone that you can seed with grass or other plants.  If you don't have topsoil or sand, substitute composted hardwood bark to make water infiltration beds.  If you need a super cheap quick solution, use raw wood chips obtained from tree trimming companies.  (Set potted flowers into the wood chips to improve appearance).

(7)  French Drains are holes filled with rocks.  Period.  French drains do NOT contain drainage tile or pipe.  French drains do NOT conduct water to other places.  French drains are entirely self contained.  Many people use the term French drain as a synonym to describe other drainage technologies.  This is NOT correct.  For best results fill French drains with cobblestones for maximum water storage capacity and rapid drainage.  Do NOT fill French drains with crushed rock.  Crushed rock packs tightly so there are few spaces for water to hold or drain.

(  There is serious engineering behind French drains.  Properly constructed drains must be able to receive large volumes of water quickly, and to hold this water until it can infiltrate into the soil.  Infiltration occurs primarily through the SIDES of the drain so it is important that the hole be sufficiently large to handle anticipated water volume.  When in doubt, dig your French drain DEEPER.  More depth = greater capacity and faster infiltration.

(9)  If you cannot obtain cobblestones to fill a French drain, use scrap concrete blocks LAID SIDEWAYS so holes will not fill in.  Back fill around and over concrete blocks with river pebbles or rip-rap = orange to grapefruit size rocks.

(10)  Send me an e-mail if you need further information about water collection, storage, and spreading systems.

ERIC KOPEREK = erickoperek@gmail.com

end comment

(7)  French Drains are holes filled with rocks.  Period.  French drains do NOT contain drainage tile or pipe.  French drains do NOT conduct water to other places.  French drains are entirely self contained.  Many people use the term French drain as a synonym to describe other drainage technologies.  This is NOT correct.

I beg to differ with you on this point.  French drains, as first described by Henry French of Massachusetts in the mid 19th century, did use tiles at their base, and did divert water to other places.  The tiles were usually either perforated, or set with gaps to allow some filtration, while carrying the bulk of water to a safe distance.  They became quite popular around building foundations, and agriculturally to drain excess water from fields.  Most were designed for a slow seep, combined with a slow diversion (usually between 1:100 and 1:200).

TO:  John Polk
FROM:  Eric Koperek = erickoperek@gmail.com
SUBJECT:  French Drains versus Henry French Drains
DATE:  PM 2:14 Friday 22 September 2016
TEXT:

(1)     French Drains date back into the historical mists of the Middle Ages = long before Henry French was born.

(2)     When knights went clanking around in armor, a French Drain was a relatively narrow, deep pit filled with cobblestones (similar to a well).  French drains were used where surface gutters were inconvenient and underground conduits too expensive.

(3)     Illustrations and descriptions of French drains (Exhauriebat Francorum) can be found in the following historical works: De Aedificatione (1516), Artem Constructionis (1620), Aedificium Constructione Liber (1663), and Liber de Aqua Ipsum (1690).

(4)     I read architecture at the Bauhaus before the war.

ERIC KOPEREK = erickoperek@gmail.com

end comment

John Polk wrote:I beg to differ with you on this point.  French drains, as first described by Henry French of Massachusetts in the mid 19th century, did use tiles at their base, and did divert water to other places.  The tiles were usually either perforated, or set with gaps to allow some filtration, while carrying the bulk of water to a safe distance.  They became quite popular around building foundations, and agriculturally to drain excess water from fields.  Most were designed for a slow seep, combined with a slow diversion (usually between 1:100 and 1:200).

Wikipedia agrees (though I admit Wikipedia can be wrong, but certainly, in my experience, people use French drain to mean a gravel-filled trench with a perforated pipe in it)

A French drain[1] or weeping tile (also blind drain,[1] rubble drain,[1] rock drain,[1] drain tile, perimeter drain, land drain, French ditch, sub-surface drain, sub-soil drain or agricultural drain) is a trench filled with gravel or rock or containing a perforated pipe that redirects surface water and groundwater away from an area. A French drain can have perforated hollow pipes along the bottom (see images) to quickly vent water that seeps down through the upper gravel or rock.

French drains are primarily used to prevent ground and surface water from penetrating or damaging building foundations. Alternatively, French drains may be used to distribute water, such as a septic drain field at the outlet of a typical septic tank sewage treatment system. French drains are also used behind retaining walls to relieve ground water pressure.

Would a good start to the problem to be fixing the roof runoff?