Dear James: There are quite a few minor landscaping and repair jobs I need to do that require the use of concrete. I have never worked with it before. What are some general tips to get me started out right? — Myra W.
Dear Myra: Working with concrete is not as difficult as people often think. The toughest aspect of most new concrete or repair jobs is carrying the sack of cement or premixed concrete from your car trunk to the job site.
Concrete is simply a mixture of cement and an aggregate (sand and/or gravel). The cement is the glue that holds the entire mixture together. The addition of water to this mixture causes a chemical reaction to occur that solidifies the cement and the aggregate in it.
Since it is a chemical reaction and not just drying out, it is usually best to wait to do the concrete work until the area is shaded if possible. On hot days, you may have to lightly mist the surface so it does not dry out before the chemical setting action has completed.
The percentages of cement to aggregate and the type of aggregate used determine the strength of the cured concrete. For most landscaping and small repair jobs, any strength mixture is generally adequate.
Depending on the size of your job, consider using premixed concrete you can buy at most hardware stores and home centers. It is available in many mixtures (various types of aggregates) and the package usually indicates its recommended uses.
Premixed concrete can be purchased in bags small enough to lift out of your car trunk. Be careful though because even the small bags are much heavier than they appear and it can be awkward on your back when lifting something out of a trunk.
For larger jobs, you should have a concrete company deliver wet concrete ready to pour. It is purchased in cubic yards, so calculate the volume you will need. Have several friends ready with wheelbarrows when the concrete truck arrives. You have a relatively short preset length of time to move the concrete from the truck to your project site.
Wear rubber gloves when working with concrete or any uncured cement-based materials. Although it may not hurt initially, cement is caustic and it will irritate and severely dry out your skin. Dry cement, even in unopened bags, is very dusty, so wear some coveralls or old jeans too.
Almost any concrete job you will do requires that you build some type of form to hold the concrete until it cures. Forms are also important to make the concrete job level so that there are no puddles after a rain. If your concrete project will be against your house, slope the form slightly so rainwater flows away from the foundation.
Drive a few wooden stakes into the ground first at the location of the ends of a form side and one in the middle. Clamp the form to the stakes with C-clamps and check its slope. Once you have it adjusted properly, nail the form to the stakes and add more stakes in between them for support.
Wet the forms thoroughly and pour the wet concrete into them. When the form is full, use a tamper to tamp the wet concrete to compact it. Another method is to put rubber boots on your kids and have them walk around it in. Drag a straight 2×4 (used as a screed) over the forms to smooth and level the top of the concrete. Place grooves (expansion joints) in the partially cured concrete every four to six feet.
Send your questions to Here’s How, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.