There are to many concrete design systems, that are in use in the construction industry today to cover here, so we will focus on a few of the basic systems used in Residential Construction, Commercial Construction and Government type construction.
We will preface this section by saying that no two projects are alike and every project is unique. The information below should be used as a guide only.
Always consult with a licensed professional to evaluate your specific project.
Within this section we will attempt to provide and equip the home owner with the information needed to make a responsible decision regarding the most commonly used concrete design in the New Orleans Metropolitan Area.
We will focus mainly on a common term that the construction industry calls “flatwork”. The construction industry considers flatwork mainly as all of the concrete that is poured on the ground and is not supported by pilings or is not part of the main house foundation. The most typical types of flatwork are sidewalks and driveways. Patio covers, when they are not part of the house slab, are typically considered flatwork.
Replacement of Existing Sidewalks and Driveways
There are approximately six steps involved with replacing the existing concrete sidewalks and driveways at most residential properties, all things being equal. This process is based on replacing all of the sidewalks and driveways. Every project is unique and there is no “one size fits all”. There are chapters and chapters of construction information and we are not trying to re-write them. In summary, the six steps are as follows:
· Demo or break out of the existing concrete: The existing sidewalks and driveways are removed most typically with a mechanical piece of machinery called a skid steer. The concrete is broken with a jackhammer attachment then loaded into dump trucks and hauled away.
· Adjust the new concrete to the proper elevation: In many cases a home owner is replacing the existing concrete due to cracks and settlement. Depending on the amount of settlement, welcome to South East Louisiana, a skid steer is used to add dirt fill to bring the new concrete back up to the proper elevation. River sand is the most typical fill material that is used for this purpose. The river sand is hauled from a nearby sand pit by dump truck and mechanically spread. Concrete work that is performed at the rear of the house involves hauling the sand fill with wheel barrows and manual labor.
· Install the concrete formwork: There are multiple methods used as formwork in the concrete industry. We will focus on what is typically priced, estimated, used in the markets in New Orleans, Metairie, Harahan, Kenner, St. Charles Parish, LaPlace, Jefferson Parish and the nearby areas. The typical formwork materials used are dimensional lumber, mostly 1x4 lumber. The concrete thickness for most of the projects referenced in this section is four inches thick, thus the use of 1x4’s. The dimensional lumber is used as a border to keep the concrete set in place until it sets. For the most part the layout of the formwork will match the layout of the concrete that was removed. There is much more involved with the proper installation of formwork than we will cover here. One thing to note is Expansion Joints. Typical expansion joints consists of 1x4 pressure treated dimensional lumber and are strategically placed to allow for the expansion and contraction of the concrete as a system.
· Install the steel re-enforcement: Typical installation of the steel re-enforcement involves installing rolls of wire mesh, a welded wire fabric more technically known as 6x6W1.4/1.4 (10 gauge)x5’x150’ ASTM A185 Concrete Wire Mesh Roll within the area of concrete. The second most common steel re-enforcement component are rebars of varying length and diameter. The rebar are typically used to tie concrete panels of various lengths and widths together. They are also used to tie the new concrete flatwork to the house slab as appropriate. Again chapters and chapters on how to tie steel in concrete. These are the most basic.
· Place and finish the new concrete: The more common mix of concrete used in flatwork, as discussed here today, is a mixture of sand, cement and rock/aggretate to create concrete. The strength of the concrete is measured in pounds per square inch (PSI). The mix design used today for most flatwork is 3,000 PSI and is typically four inches thick. The concrete is delivered by concrete truck and is typically either mechanically pumped in place or manually wheeled in with wheelbarrows. The overview process is to place the concrete within the formwork, strike off the concrete or screed the concrete, float the concrete, edge the concrete, fine finish the concrete and broom the concrete. Placing and striking off or screeding the concrete is a means of consolidating the sand, cement and aggregate mixture to the desired density.
· Remove the formwork: Removal of the formwork is pretty much as it sounds and is typically done with a day or two of when the concrete was poured.
Stamped concrete involves placing and finishing concrete for driveways, walkways, patios, etc., and then impressing both patterns and textures and colors onto the concrete before it is fully set. For many years, a lesser form of stamped concrete was often seen that merely duplicated patterns. But the newer types of stamped concrete impart textures that duplicate many different surfaces such as cobblestones, brick, pavers, wood, seashells, and more. Also, pigment is usually added to stamped concrete to further duplicate the look of such patterns.
The Three Most Common Types of Exterior Decorative Concrete Projects That Are Used in Single Family Dwellings.
Home Owners Should Be Familiar with at least these three systems when hiring a company to perform decorative concrete projects at their homes.
Type One – Stamped Concrete System
The Stamped Concrete System consists of a process of installing concrete sidewalks, drive aprons, driveways and patios much like non Decorative Concrete Projects. The primary difference between decorative and non-decorative concrete projects is when it comes time to finish the concrete.
A Little Bit About Colors
There are several ways to add color to concrete. There are two basic methods that most companies use in the marketplace today to add color to the concrete.
An Integral Color Mix and a Shake-On Color Hardener. Each manufacturer of the products available in the market varies, but most manufacturers offer between approximately eight and twenty five colors to choose from.
The integral color mix, typically comes in 50 pound sacks and are poured directly into the concrete truck at the job site.
The shake on color hardener typically comes in 60 pound pails/buckets and the color is hand applied by throwing or broadcasting color on the surface of the concrete during the concrete pour.
We use a product manufactured by Butterfield Color. The website for Butterfield Color is www.butterfieldcolor.com Look for the Perma-Cast Shake On Color Hardener Color Chart to see the available colors. The Uni-Mix Integral Color Chart is available as well.
After the concrete has been colored, it’s time to finish the concrete. As with colors there are several ways to add a decorative finish to the concrete. We are only going to focus on a few that are the most common in the market place mainly based on budget.
During the concrete finishing phase of the pour, large rubber mats are used to add the decorative pattern to the concrete. Manufacturers vary, but each mat typically measures approximately two to three feet in length and width, depending on the pattern, and has two handles to operate the mat properly. Several mats are used during the concrete finishing process. The mats are placed on the concrete, tamped with a tamping tool which transfers the pattern to the concrete and are then moved in a sequential manner from start to finish.
We offer two patterns of stamped concrete to choose from.
o Ashler Slate
o Old Chicago Herringbone
After the concrete has set, typically one to three days, the concrete forms are removed and the concrete is prepared and touched up and ready to be sealed. Sealing of the concrete involves the process of installing up to three coats of a concrete sealer to seal the concrete and to protect and enhance the finish color.
There are several factors that affect the cost of construction. The cost of a project today is not the cost of that same project weeks, or even days, later. Every project is unique and needs to be priced out accordingly. The average costs of projects that are quoted below are for budget discussion only.
The average costs of a typical stamped residential concrete project start at $6.00 to $8.00 dollars per square foot, and up, depending on several variables of the project.
Type Two – Scored & Colored Concrete System
The Scored & Colored Concrete System consists of a process of installing concrete sidewalks, drive aprons, driveways and patios much like non Decorative Concrete Projects. The primary difference between scored and colored and non-decorative concrete projects is when it comes time to finish the concrete.
The concrete is finished the same way as non-decorative concrete except that within approximately one day after pouring and finishing the concrete, it is scored to specifications. Most typical finishes are 24”, 36” & 48” squares or tiles with machine cut grooves or grout lines cut into the concrete.
The concrete color for scored concrete systems are identical to the color process used with the stamped concrete system and explained above.
Scored & Colored Concrete System costs vary widely based on the detail level of the overlay project. Starting costs for the basic overlay start at $8.00 to $10.00 dollars per square foot and up.
Type Three – Concrete Overlay System
The Concrete Overlay System is installed much differently than a typical stamped concrete system. The concrete overlay is more suited to existing structurally sound concrete that has become old looking or in need of an upgrade.
The concrete overlay system is more suited for use over existing sidewalks, driveways, patio covers and interior floors. The overlay system can be stamped, scored or patterned and colored many different ways.
The concrete overlay consists of a system whereby a cilica based polymer cement with a finely graded sand, is installed approximately 1/8” to ½” inch thick over the existing concrete. The existing concrete must be level, structurally sound and not have any cracks in the finish. Cracks in the existing concrete will allow moisture to deteriorate the bond between the existing concrete and the overlay and will eventually cause the failure of the system and will de-laminate away from the existing concrete.
The overlay material we use is also manufactured by Butterfield Color. The system is Butterfields T-1000 Stampable Overlay. The T-1000 can be used in conjunction with Butterfield Color® T1000™ Color Packs to achieve a multitude of colors. The color packs are available in all Uni-Mix® Integral Colors and are designed for use with one bag of overlay.
Concrete Overlay Systems costs vary widely as well based on several project specific requirements that drive costs up or down. Budget costs start at $9.00 to $10.00 per square foot, and up.
Feel free to give us a call. We offer free estimates and an evaluation of your project.