How to Use a Concrete Screed

A concrete screed is a long board, often cut from dimensional lumber, which is used by two or more workers to level the surface of wet concrete. After the concrete is dumped into flat-work forms and spread out with shovels or concrete rakes, it's time to use a screed. For pours less than 8 feet wide, two workers can usually control the screed. When the pour is wider, a third worker may be necessary.

Difficulty: Challenging

Instructions

Things You'll Need:

• Screed board Screed vibrator (optional) Safety goggles and clothing

1. Select a screed board that is a couple of feet longer than the width of the pour. For instance, if you are pouring a driveway that is 10 feet wide, use a screed board that is at least12 feet long. Dimensional lumber, either 2-by-4 or 2-by-6, is commonly used as screed boards.

2. Position two workers with strong backs at each end of the screed board. Smoothing out wet concrete is hard work and the wider the pour is, the more difficult it will be.

3. Hold the screed board so the narrow side of the board rests on the wet concrete and on the forms that surround the concrete. Allow a bit of the board to extend past the form at each side for the screed operators to grab.

4. Start at one end of the newly poured concrete and begin sliding the screed board towards the other end. At the same time, each worker will employ a sawing motion, back and forth with the screed board to smooth the wet concrete.

5. Another worker should stand by with a shovel of wet concrete to sprinkle into low areas as the screed passes over. When a low area appears, stop screeding and as soon as the void is filled, lift the screed and go back and re-screed that area again.

6. Repeat the screeding process at least one more time across the entire length of the pour. The movement of the screed back and forth will get small bits of gravel in the concrete to settle downward while moisture and air bubbles will rise to the surface of the wet concrete, making the final product stronger.

7. Attach a power screed vibrator, if possible, to the middle of the screed board. These vibrators are powerful and will vibrate the entire board when switched on. If you use a vibrator, the screed operators just need to pull the board, but can skip the sawing motion.

Tips & Warnings

• Add a third person to the screed if the width of the pour is more than 10 feet and you do not have a power vibrator. This person will stand in the middle of the wet concrete and use a concrete rake to pull the screed along.
• Wear safety goggles to keep splatters from getting in the eyes, and protect your skin with long-sleeve shirts, long pants, rubber boots and a cap. Concrete will leach the moisture from skin very quickly.

References

• John Taylor, owner: Taylor Construction, McPherson, KS. Cellphone: 775-830-1562