Concrete Slabs

servicing Council Bluffs, Omaha

and surroundings

Licensed and Insured

Need a concrete slab for a shop, garage or even a pole barn? We can do that! At Nixon Construction, Inc. our vast experience as a respected concrete contractor enables us to deliver projects on time and within budget for our customers. 

What makes a good concrete slab

Here are some things to look out for when you’re browsing through some concrete slab pictures online trying to choose which contractor to hire. For the untrained eye, major defects are not always easy to spot.

1) Base: Did that contractor tear out and put a solid base for the concrete? The base under the slab is just as important as the concrete itself. They need to have crushed rock put under the slab. It should be compacted solid. If this is not done properly. The base can erode causing future problems. 

2.) Formwork: When u see the formwork, the forms should be put together in nice straight lines and square edges. When you have a radius to the work, they should be nice and fluid as well. Look out for braces securing the forms to prevent blowouts. Concrete is very heavy, improper bracing will cause the forms to fail.

3.) Concrete: When they pour the concrete, It should be poured at a reasonable slump (wetness). Pouring concrete too wet can cause issues, especially in colder climates. Including a delaminating surface.

4.) Craftsmanship: When you first look at concrete jobs. One of the first things you notice is the control joints. These joints are made to control cracking. They should be straight. They should also be 25% depth of the slab. These are critical to having a job done right.  The formwork and edges should be uniform. The concrete should not have noticeably dipped or rolled edges. The broom finish should be straight lines. You can have soft, medium, or a heavy broom finish depending on the job in question.

What are the most common thicknesses for slabs?

The most common thickness for slabs depends on the traffic that will be using it.  For a backyard patio. It is common to have a minimum, 3.5″ thickness. This is sufficient enough to hold regular foot traffic. Proper joints and expansion need to be applied.

The most common thickness for a driveway is a minimum of 4″ thick. Also, take into consideration using a type of reinforcement to help the concrete. Wire mesh can be used in pours that are 3.5 to 4”. Rebar can be required if the soils behave poorly. Rebar is best utilized in a driveway for which 5-6 inches of concrete can be poured. This is because rebar is relatively thicker than galvanized mesh reinforcement. Joints need to be approximately  2.5 times the thickness of the drive. This will help prevent cracking and keep it controlled in the control joints.

 Curb: When you get out more into the street you have a tendency to have heavier traffic. Curbs are poured approximately 8″ deep. This is measured at the flow line going down to the subgrade.

For heavier traffic, it is recommended to pour 8″ + thick. Rebar may need to accompany this on 2’ to 3’ centers.

  

How long does it take to cure? When can I use it?

  In standard industrial cases, full strength concrete is recognized at 28 days. At seven days, you should have concrete that is cured to 70% full strength or greater. You do not want to rush the curing process.

A slow cure is best for the long term strength of the concrete. You may want to use a cure n seal the day u pour. It will trap the moisture in the concrete and allow for it to cure at a slower rate.

You may also wish to spray water on the concrete starting the next morning. It will keep the concrete cooled off and allow for a slower cure. 

Although the concrete will harden or set soon after pouring. It is still susceptible to damage from weight during the first four weeks. Wait at least 24 hours before allowing foot traffic, including pets, on a newly poured sidewalk, slab or driveway replacement.

Do not drive a vehicle on a new driveway for at least 10 days. At 10 days,  it’s OK to drive on your new concrete with normal passenger vehicles. At this time the edges and corners of the concrete are still considered brittle compared to the middle of the slab. Avoid driving near or across the edges of a driveway since those areas are still weak.

How to maintain? (also what to avoid)

Now that you have your new concrete poured. Its time to maintain it. Make sure you have either applied a “cure and seal” or “sealer” on your concrete. This should be applied when you poured the concrete.

It is also recommended to repeat this every 4-5 years. The sealer will help safeguard your concrete from weather conditions, spills, and other substances. If you used a Solvent-based acrylic sealer for your concrete, you can reapply it on top of previous solvent-based acrylics.

Do not mix and match water or acrylic-based sealers!

Once a previous sealer has been removed you are then going to want to clean the concrete before applying your new coat of sealer. The best time to spray or roll your choice of sealer is early morning or late afternoon. This way you can avoid the hottest part of the day which can cause blistering issues with the sealer.

 Spills: It is also wise to remove spills as soon as possible. This can lead to staining your concrete.

Cracks: Concrete cracking can happen at no fault of the installation. If you do see a crack appear. It is best to fill that crack in with an epoxy or latex patching compound as soon as possible. This crack, if not properly repaired, can start to accept water.  Water seeping into a crack can cause problems. If water penetrates in the winter it can freeze underneath the slab and cause it to rise and possibly cause more cracks. 

 Cleaning your driveway is a regular part of your maintenance and should not be overlooked.

 Are there things you should avoid doing to your concrete? Yes!

Avoid salt! Salt does not damage concrete directly, but the effects of salt can, and will.  Salt does not chemically react with hardened concrete. Salt does, however, lower the freezing point of water. The continuous freeze/thaw caused by the salt can cause heavy damage to the surface of your concrete. The salt damages concrete by causing corrosion to occur under the surface, causing it to pop and crumble. Sand and kitty litter are safe alternatives to using salt on your concrete.

We are a local contractor servicing the Council Bluffs and Omaha areas

Everyone of us are proud serving members of the community. We are hard working and take our business seriously. Our reputation is based not only on quality work but on trust. Did you see our five star reviews? Check out the maps below to see some areas we regularly perform concrete work.