Expert: Dan Griffin - 12/17/2008

Question
QUESTION: We live in az and have a couple spots around foundation that when it rains the water will stand.  I think it can be solved by just adding a litte earth to the spots to drain it away from the house.  Do you recommend dirt or sand?  Also, one of the areas that the water stands is on the back patio, which is tiled.  Should I remove the tiles first, or add earth on top?  It only rains a few days a year here and there are no signs of moisture in the house but I do want to get rid of the standing water.

ANSWER: James, I started to ask if it ever rained in Arizona.  I can't see the situation, so I don't know where the water was designed to go.  It is quite normal for the soil around the house to settle as it had been disturbed and often pushed back with little or no compaction.  If you can raise the dirt grade without violating the building exterior, it would be the easiest.  Spread some top soil, rake out, allow the grass to grow up through.  Repeat as necessary.

If this a concrete slab home with a stem wall and the exterior grade is  about 6" or more below finish floor, don't worry about it, it is doing no harm.

Does it appear the patio has settled lower than it was originally?  Most patios have a 1/4 per inch fall to shed water.  You might talk to a company that mud jacks foundatons to see about raising the patio without destroying it.

---------- FOLLOW-UP ----------

QUESTION: Ya it doesn't rain often but once in a while such as during monsoon, we can get rain for a week straight and then go months without.  Thus, I would rather not have that standing water.  The house is concrete slab but not sure what stem wall means.  Are you saying if the pool of water is 6 inches below the adjacent floor on the inside of the house that it is ok?  The only thing I can tell for sure is that there is a good few inches from the slab to where the stucco starts and the stucco is not near the water.  As for the patio tile, it is old and coming apart and the area that pools is at the end of the house next to the gate so I dont have a problem just putting a little earth on top of it if that will help.  What do you think?  And is dirt better then sand?
Thanks!

Answer
James, there is no way for the water to harm what you have if the stucco/EIFS is above the water by several inches.  I suspect they poured a footing that you don't see below ground, here it has to be 18" for frost, yours will be less.  They form up about a 6" thck by about 24" tall wall around the perimeter on which the walls will sit (stem wall).  Install ducts, plumbing, etc underslab, fill up with sand, pour floor.  The water you see on the outside is well below finish floor and doesn't hurt anything.  Other types of foundations really care, but not yours.

Dirt or sand will probably just hold water on the patio longer.  You could use some topping cement to raise the concrete.  A good one that is fairly to easy to use is Planipatch made by Mapei.