There are many important things to be concerned with whenever concrete is poured. These are my top 9 in importance.

1. Know the weather. Concrete behaves differently for each extreme of weather. If it’s going to rain, find something else to do on that day. I have been caught more times than I want to remember pouring when it rained afterwards. No matter how good your finisher is, he can’t do you a good job in the rain, and the concrete strength is going to be lessened because of the dilution by water on the surface. Pouring footings with some chance of rain is not the same as pouring a finished product before a rain. If the temperature is dropping below frost following a pour, it can be done with the use of a drying agent. This cost extra money, and doesn’t always render the desired results. If the weather is extremely hot, the concrete is going to need more water to keep it from setting too fast.

2. Have enough help to do the work. This sounds simple enough, but an extra two men is much better than one man short. I have been caught with too little help and concrete on the job, with nothing to do but put it down and fight. Concrete doesn’t abide by your time, but its own. On the farm we knew that when the corn was ready to pull for eating and putting in the freezer, we had to get it. It wasn’t a job you could allow to go until you had time. Concrete is the same way. At least with the corn, we knew we had two or three days. Based on the weather, concrete can set before you can get a drink of water. Limit the amount of concrete you are pouring to the number of people you have. If you are doing flat work (driveways, sidewalks, decks), three or four people (who know what they are doing) can handle ten to twenty cubic yards easily in moderate to hot weather. If you plan to pour 100 yards, that number would increase to six or eight. My suggestion is to get a reputable concrete contractor for any large pour you might attempt.

3. Be sure the area you are pouring has sufficient compaction to hold the weight of the traffic that will come. Concrete is tough stuff, but won’t last with inferior material beneath. Most residential work makes it cost prohibitive to have compaction tests run for driveways and the like, but, if there is any doubt as to the compaction, it may be necessary to compact with a vibratory roller.

4. Know where the water will go when the concrete is poured. You don’t want a bird bath when it rains. No outside pour should be flat. Use a level, transit level, or laser level to determine which way to turn the water.

5. Order enough concrete to do the work. If you come up short on a pour and have to wait for more, you have a cold joint where the materials will set up differently and cause a weakened area. This is true especially in hot weather. Calculating concrete is based on area x thickness. Most sidewalks are 4” thick, and paving can be 4” to 6” or more. For residential, high traffic areas with heavy loads, I recommend 6”.

6. Don’t skimp on the strength of concrete. To go from a 3,000 psi concrete to a 3,500 psi will cost a few dollars, but it is worth it in the long run. On very critical high traffic areas, 4,000 psi might serve you better. It use to be a requirement for footings to be 2,800 psi, but 3,000 has become the standard for most footings and foot traffic slabs.

7. All large pours of flat work should have control joints. Concrete is going to crack, but you can control the cracks to some extent by saw cutting or tooling in control joints. The idea is to make blocks that are the same dimension in both directions. For instance, a 10′ wide driveway would be tooled every 10′ across. It sounds simple, but every situation isn’t a rectangle, so you can’t always have perfect square areas. If you have a 20′ wide driveway, you might consider a center control joint to keep your squares to 10′ x 10′.

8. Use reinforcement where it’s needed. No matter what strength your concrete might be, given the right weight of a vehicle it can break. Many driveways are poured with no wire, and some hold up okay as long as large trucks don’t cross them. It is always a good idea to use wire where auto traffic occurs.

9. Don’t add more water than is necessary. Concrete masons have a habit of getting the truck driver to add water the minute he drives up, even before they see the consistency of the material. It makes perfect sense to want it thin so it can be moved and placed easier, but that extra water dilutes the strength. Water is the critical factor in every mixture. The best concrete has the minimal amount of water required. As I mentioned earlier, sometimes it is necessary to add water in hot and dry weather, but even that should be done carefully.

That’s my nifty nine tips. Talk to you later.

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