Things You'll Need
4 boards, 2 inches by 4 inches by 18 inches
1 board, 2 by 4 inches
1 board, 2 by 8 inches
8 wood stakes
Roll of rebar wiring
Long sleeve shirt
Portland cement is the key ingredient of concrete. Concrete also consists of crushed rock, sand, gravel and water. The water makes it pliable until the concrete dries, and then it becomes rock-hard. Many people don't think of it, but concrete is fire-resistant. Heavy weight is concrete's enemy, along with the weather, which can cause cracking and erosion. Concrete needs to be at least 5 inches thick, be grated with rebar wiring and have a strength of 3,000 pounds per square inch to be a suitable foundation for a car lift. Some car lifts have two support posts, others four; build a pad for each post.
Build a form for the concrete. Chisel out the current flooring and level as much as possible with sand and crushed rock. Tamp the sand and rock. A form is nothing more than 2-by-4-by-18s. Nail the 2-by-4s together into a square form for the car lift. Use a bubble level to keep the form straight. Use stakes to keep the form in place.
Spray inside the form with water. Do not soak, just moisten the ground. Spread rebar wiring on the bottom of the concrete form.
Dress appropriately; wet concrete is alkaline and can cause chemical burns to the skin on contact. Appropriate clothing is a shirt with long sleeves, work pants, gloves and rubber boots. When mixing concrete, airborne dust can cause eye irritation; wear goggles.
Mix 1 part Portland cement to 2 parts sand and then 2 parts gravel in a wheelbarrow. You can substitute crushed rock for gravel. Add water until the concrete becomes the consistency of stiff pancake batter.
Pour the concrete from the wheelbarrow into the form.
Fill the form to the top and tamp the wet concrete with a roller tamper. Set a 2-by-4 on top of the concrete form so you can slide the edge of the 2-by-4 along the top of the cement to smooth it out.
Slide the 2-by-4 back and forth in a sawing motion to get the wet concrete level. Run a magnesium concrete rake over the parts of the form you cannot reach.
Run a 2-by-8 with a groover attached over the top of the cement to cut contraction joints. Contraction joints allow the concrete to expand and contract when temperature changes.
Chemical burns require medical treatment. If your skin comes in contact with cement seek medical treatment.