Vapor Barrier and Cables

Saturday, September 16th:

Mom and dad are out of town this weekend visiting friends and family in Tulsa. Mom participated in Race for the Cure, and has done so each year since she went thru breast cancer herself. I decided to have a look at the progress made on the construction of their house.

The foundation is called a post tension slab. The first step is to trench the beams for the areas of thicker concrete. After the plumber runs water and sewer lines for the house, the concrete company adds the vabor barrier and cables, which like the grade beams (trenches in the dirt work) run in a grid. These cables run thru a red sleeve so the cable does not come into contact with the concrete when it is poured, then after the concrete has cured (28 days), tension is put on the cables, which serves to pull the foundation together into one cohesive unit. This deters differential settling of the slab, which results in foundation failure. In essance, the soils here are clay, so they expand when wet and shrink back when dry. As this can not be avoided, the foundation is designed to "float" on the soil.

This view is taken from the front. The foundation is scheduled to be completed on Monday, however, rain is in the forecast.

This picture shows the anchors, which are attached to the inside of the form board. The cables are slid thru the ones shown so the cable extends out of the concrete. After the concrete cures, a machine is clamped to the end of the cable, and pulls the cable until it reaches the desired tension. The anchors do not allow the cable to slip back, thus ensuring it stays under tension. The extra cable is then cut off, capped, and finished over. The other end of the cables have anchors, also nailed to the inside of the forms, but the cable does not extend thru the anchor.

Here I am seen checking the plumbing rough with the plans. The area I am looking will eventually be the master bathroom.

Whoops, I've discovered a problem. The plumber appears to have missed the rough-in for the sink in the laundry room. That will have to be added on Monday.