As you can see in the photo above, steel rebar is simply steel that is melted into the shape of long tubes. The term “rebar” is short for reinforcing bar and is used in concrete to increase it’s tensile strength. Rebar is typically constructed with high yield steel by heating it to its liquid form and then shaping the tubes to spec. Steel rebar can last up to 80 years before it starts to decompose. This makes building with concrete much more stabile and long lasting.
Typically, we use steel rebar for high wind zone residential footing construction. Every wind zone classification can be found on the NIST.gov website here: Wind Zone Map.
For home construction in areas designated as high wind zone, steel is required to be placed continuously throughout the entire footing after excavating but before pouring concrete.
LAYOUT HOMES – We actually use steel rebar stakes that have been cut down to about 18″ in length to do our footing layouts with. Basically, we use 100ft tape measures and steel rebar (as stakes) to find our corners. The tape measures will hook onto the #3 rebar stakes easily, so it allows us to pull measurements and square the layout. We also use the combo for our pier rows and those pesky little bump outs that architects throw in from time to time.
CHISEL – Transform rebar into a chisel by cutting it down to the desired length and grind the end to make it sharp. It will break through almost anything, including concrete.
TREE STAKING – Rebar can be used to stake or hold things in place all around your home’s exterior landscape. They are great for tying down trees because they won’t move if inserted far enough into the ground.
Whether rebar is needed for your footing depends on a number of factors including location, soils quality, code requirements, and other special conditions.
If your home plans have an engineer’s stamp of approval, any requirements regarding steel rebar will be included in the detail sheet(s).
The region and wind zone that you are building in will dictate what is required by your local state and county codes. Areas that are seismically active definitely require steel rebar in the footing construction. Coastal areas and places like “tornado alley” are all designated as high wind-zones and require steel reinforcement also.
Every state has it’s own building code book or binder that you can purchase to find out the code requirements in your state. Some states offer a digital as well as physical version of the book for your convenience. Shop their store here: International Code Council. Look for “Residential Construction Code”.
In some states, horizontal steel rebar is required for all residential dwellings. In other states, it is only required in two-story homes. Here in North Carolina, steel rebar is only required in high wind-zones and in seismically active areas.
Basement walls bare a lot of weight from the adjacent soil that they are built into. They almost always require vertical steel, especially if they are also supporting the foundation wall above.
When joining a new footing to an existing footing, it is required that we dowel with steel rebar to permanently adjoin the two before we pour the new piece of footing. This is usually a component of home additions as we are building a new structure and attaching it to an existing structure.
It all depends on what you are building, what your local weather looks like, and what your state building code requires to figure out if you need steel rebar in your residential footing.
Additionally, if you live along a coastal area or a seismically active area then you are most likely required to have steel reinforcement for you footing. If you have any questions, feel free to call your local county building inspections office. They most certainly can tell you what code requires in your county.