Question:

I'm in the process of building a fence but the last  area is giving me
trouble. The problem is that the holes I dug are filled with water from the
rain we have had the past few days. They are right next to my driveway and
it slopes right down into my backyard. I think the reason it is retaining
water is because there was a high concentration of clay in the hole, and
because I live half way up a hill. Can I still put the posts in with
concrete? Or will it just rot the wood (I'm using pressure treated) after a
while because of the water? Any suggestions will be greatly appreciated.
Thank you
(name withheld)

Reply:

SAFETY TIP FIRST:
Never drill holes ahead of the day you are going to concrete them. Avoid potential injuries should someone should fall in them. Also avoid water filling them up and causing cave-ins and other problems.

If your holes have not caved in, you do not have a problem, otherwise you need more tons of concrete and maybe a water pump to remove the water.

The easiest solution is to use pre-mixed bags of concrete, like Sakrete or Quikrete. These mixes have had all the water and moisture removed and are very dry.

Dip-out about 1/2 of a completely full hole with a cup or coffee can. Place your post where you want it and pour the concrete out of the bag directly into the hole. Mix it in the hole as you fill by poking a stick into the concrete. The water will rise as you gradually fill the hole. Make a very small trench leading away from the hole so the water can drain out. Leave the concrete 3-6" below the surface. If you run out of water, simply add some. If you had way too much water, remove more on the next hole before you start.

If you are working on a spec. job, you didn't hear this from me. They want all the water removed and Class 'C' concrete pre-mixed with water dumped from a concrete mixing truck. I say, it's just a fence!

As far as your treated posts, you have no problem. If they are standard in-ground .40 retention CCA treated (that's the standard for a 4 x 4), they are made to get wet. In actual water conditions, like for piers, they use .60 retention. You won't find them at DIY centers.

Good luck with your project!

Frank R. Hoover
Hoover Fence Co.
Sept. 8, 1999
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