Watching Concrete Dry

No, I'm not kidding.

I'm sitting outside on a plastic lawn chair, making sure that nobody comes by and defaces the newly replaced sidewalk.

I tried to get the corner of the screen in there so you could see that it was 25 Apr 2005, but the resolution of the camera phone isn't that good.

We had a long meeting with our contractor yesterday. We did a lot of arguing about money and contracts. While we didn't come to resolution on either of those issues, the contractor did agree to take a critical step forward to reduce our collective liability.

For the past month, the water under the house has been pumped out to a pipe which shoots a jet of water across the sidewalk and into the gutter. It's been wet long enough that algae has started to grow on the surface of the concrete, making things pretty slippery. The City of Alameda Department of Public Works isn't happy about that. They've sent a notice to Willson/Bailey, asking them to fix the problem. It's a big liability issue: if someone slips, falls, and suffers an injury, we're liable. The solution is to install a pipe under the sidewalk and drill holes in the curb where the water can exit.

Today, the contractor and crew performed that work. Here you can see where they patched the walk:

There are two pipes running under the sidewalk -- one three-inch and one two-inch. One pipe will be for the water coming from the sumps under the house. The other is reserved for the future, when we install gutters and drains for the roof, if we want to we can direct the collected water through that pipe. Both pipes enter a box filled with rocks, which interrupt the progress of the water and slow it down. Five one-inch copper pipes have been drilled into the curb; water exits the box through them. (Copper pipes change the chemical balance of the water, preventing algae from growing.)

A closer view of the pipes drilled into the curb:

The concrete for the sidewalk is still curing, as is some of the concrete used to set the pipes inside the box. Tomorrow, when it is fully cured, the contractor will hook up the sump lines and we'll see how it works.

There's a lot of water down there. The pumps run every 6 to 7 minutes and pump out several gallons of water. Yikes!

posted by noel on 04/25/05