More on Pouring Cement

Here are a few follow up items to the other day's post about pouring the cement floor.

• The actual name of the machine that leveled out the pile of cement into an even surface is called a Laser Screed.
• The layer of plastic between the gravel and the cement is there to keep moisture from coming up into the cement from the ground, and to keep the water in the cement from leaking out too quickly.
• The wire mesh reinforces the cement.  Once the cement is poured over the mesh, workers come by with a hooked pole and pull the wire up into the cement so that its actually in the middle of the cement when it dries.

The floor is now dry and solid, in fact we moved some of the steel roofing joists onto it today -- more on that soon. One last thing they did on the floor, though, was to cut grooves through the cement surface, like this:

You see these grooves in driveways, sidewalks, and other cement surfaces as well.  The reason they do this is that between temperature changes, small shifts in the earth and other factors, it's very likely there will be a crack in the cement some day.  When you have grooves in the cement, often the cracks will appear in the grooves, where you don't see them. If they appear somewhere else, they will stop when they get to a groove continue down the groove at that point (because it's the path of least resistance).