The Ultimate Concrete FAQ

High-strength bag concrete mix is a pre-blended mixture of sand, gravel, and cement. It is designed for applications where a slab thickness of 2 inches or more is required. When mixed according to directions, it reaches a compressive strength of 4,000 PSI.

There are exactly 45 bags of 80 lb high-strength concrete in one cubic yard (27 cubic feet). Each bag yields approximately 0.60 cubic feet. You can calculate this at sakretecalculator.com.

There are 60 bags of 60 lb concrete mix in one cubic yard. Each 60 lb bag yields approximately 0.45 cubic feet.

Yes, high-strength bag concrete mix is suitable for driveways. However, for a standard residential driveway, we recommend a minimum depth of 4 to 6 inches and the use of reinforcement like rebar or wire mesh.

While many brands serve the same purpose, their specific mix ratios and yields may vary slightly. Our tool at sakretecalculator.com is specifically tuned for standard high-strength yields found in major industrial brands.

For an 80lb bag, start with 3 quarts of clean water. Add water slowly. The goal is a consistency like thick oatmeal or peanut butter. If it's too runny, it will be weak; if it's too dry, it won't bond correctly.

Yes, you can mix it in a wheelbarrow or a mixing tub using a hoe. For projects requiring more than 10-15 bags, we highly recommend renting a portable concrete mixer to ensure a consistent mix and save your back.

In extremely hot weather, use cold water to prevent the concrete from setting too fast. In cold weather, using lukewarm water can help the chemical reaction start, but never use boiling water.

Bag concrete mix 'sets' within 24 to 48 hours, meaning you can walk on it. However, it takes 28 days to reach its full design strength (4,000 PSI). Do not drive vehicles on it for at least 7 days.

Cracking is usually caused by: 1) Too much water in the mix, 2) Fast drying in direct sun/wind without curing, or 3) Unstable ground beneath the slab. Proper compaction and moist curing are the best defenses against cracks.

Moist curing is the process of keeping the concrete surface damp for the first 3-7 days. You can do this by spraying it with a fine mist of water several times a day or covering it with plastic sheeting to trap moisture.

For a 12-inch diameter Sonotube poured at a 4-foot depth, you will need approximately 5 bags of 80lb high-strength bag concrete mix. You can calculate various diameters and depths using the 'Sonotube / Post' mode at sakretecalculator.com.

Fence posts are commonly set 2 feet deep. For structural deck piers, you typically need to pour 3 to 4 feet deep to ensure the footing is below the frost line. Always consult local building codes for specific regional requirements.

Yes, fast-setting bag concrete mix is excellent for non-structural posts. However, for structural deck piers requiring inspection, standard high-strength mix is often preferred for its longer working time and consistent 4,000 PSI rating.

The easiest way is to use fast-setting concrete (often in a red bag). You can pour the dry mix directly into the hole and add water on top. It sets in 20-40 minutes and doesn't require bracing in most cases.

While you can use high-strength bag concrete mix for countertops, specialized countertop mix is better because it has a finer aggregate for a smoother finish and special additives to reduce shrinkage and cracking.

Standard concrete is porous. If you need a waterproof finish, you should apply a concrete sealer after it has cured for at least 28 days.