What Materials Are Needed for a Concrete Garage?

Fill Sand

• Sand provides a firm base on which to pour a concrete garage floor. During excavation, the contractor digs the holes for the garage floor, the stem wall and the footing. The footing rests on virgin soil, meaning soil that has not been disturbed. The garage floor however, requires a layer of sand to reduce the future risk of soil movement, which could crack the garage floor. Building codes vary, but a standard layer of fill sand is 2 to 3 inches, spread, leveled and compacted before pouring the floor.

Reinforcement

• Concrete is hard, but its tensile strength comes from steel reinforcement. In every step of garage construction that involves pouring concrete, you’ll need to add steel. Local building codes regulate the amount needed, and an inspector may examine your concrete forms to ensure that you’ve added enough before clearing you to pour. Steel rebar is standard for reinforcing concrete. In the footings and in the floor, the contractor will lay rebar rods lengthwise and widthwise and bind them where they cross with rebar ties. The same reinforcement is necessary in the vertical concrete walls, using vertical and horizontal rebar, secured with ties.

Concrete

• You’ll pour concrete at least three times during the construction of a typical concrete garage. The footing pour is first, and for a standard footing that is 12 inches deep, 24 inches wide and 26 feet long -- which is an approximate length of one garage wall -- you’ll need two yards of concrete. A complete 26-by-26 garage would use eight yards of concrete for just the footing.

  Concrete walls require one yard of concrete for every five lineal wall feet, when constructing a standard 8-foot wall that’s 8 inches thick.

  A concrete floor that’s 4 inches thick and 26 feet wide and deep, will take almost 8 1/2 yards of concrete.

Prestressed Concrete Panels

• Many concrete garages have regular wood framed roofs, but if you want a completely concrete garage, it’s better to use prestressed concrete panels here than it is to form and pour an overhead ceiling. These panels come directly from the manufacturer and are engineered specifically for your garage. Once the garage walls are in place, the concrete company will bring the panels to the job site on a boom truck and set the panels for you.

Additional Materials, Supplies and Tools

• You’ll need electrical wire to install lights, switches and outlets in the garage and you'll need one or more garage doors, depending upon the size of the garage. Solid concrete offers some insulation factor, but you can add rigid foam insulation panels to the interior of your garage, if desired. Although concrete forms don’t go into the actual construction of your garage, you will need them to pour the garage walls. The forms and tools for working concrete, including trowels, concrete floats, screeds and vibrators are available from construction rental stores. Workers knowledgeable in pouring concrete should be on site and in control of the pours.