Question
Hello,
My daughter had a concrete patio made.  Instead of cutting the rain gutter (from roof down side of house) the contractor cemented the gutter into the patio so it is now draining under the cemented patio.  Last night we noticed her hardwood kitchen floor soaking wet.  The patio is off the kitchen.  Is it possible that the rain that fell into the roof drain and down the side of the house in the gutter, got plugged or backed up because the water had no where to go from the previous rain OR possible all the water used washing off the patio could have backed up causing damage to the floor.  Thank you for your help!!

Answer
Hello,

It is possible that water is backing straight up the downspout,overflowing onto the side of the house and from there leaking into the kitchen and/or pooling under the patio and leaking into the kitchen from there,depending on how high the kitchen floor is from the patio.

Remove the downspout from the patio and install a new one and connect it to pipe that runs either on the surface or beneath the patio if possible.
There must be an outlet that allows the water to drain away a safe distance from the house. The underside of the patio itself is not a good place to dispose of water.

If you want to run the downspout underneath the patio slab you will have to bore a hole for the pipe horizontally. Depending on how wide the patio is you may be able to do this by hand.

First,cut a 45 degree chisel point onto the end of a section of pvc pipe,then dig a trench perpendicular to the patio and wide enough and long enough to allow the pipe to be moved under the slab. The digging pipe should be about 2 or 3 inches in diameter.

Gouge out sections of soil  and then remove the pipe. Push a smaller pipe through the an end of the digging pipe to remove the soil plug and then repeat digging. Tap the end of the pipe into the soil with a sledge and then work it in a twisting motion like a drill.

Or you could rent a horizontal boring machine. This machine has an auger head attached to a flexible drill rod. Holes can be drilled to 75 feet in length. Im not sure if residential models are equiped for slurry (a water and bentonite clay mixture which cools the auger head,makes the soil easier to remove and the tunnel more stable).

If you bury the pipe,choose a type of pipe that is suitable for burial. That type of pipe is often rigid. The ordinary black corrugated drain pipe is not suitable for burial,although there is a type of corrugated flexible drain pipe that is.

Of course if alot of water was used to clean the patio then this may account for your flooding. In any case,it would not be desirable to have rain water emptying immediately outside your house wall and it certainly would not be desirable to drain rain water from your gutter under your patio. Good luck. Let me know if I can be of further help.

Mark Harshman
http://www.mahdrafting.com
Email: [email protected]

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