The United States cement industry produces approximately 4.1 billion metric tons annually. Cement is a key material in the US construction industry, used in all types of paving, structures, stucco, foundations, and pre-cast panels.
Concrete is so integral to the construction industry that there are at least 53,000 concrete contracting companies in the United States. Knowledge of calculating and estimating an accurate concrete takeoff is vital to ensure you complete a profitable project.
Most commercial construction projects require the use of concrete. Concrete is popular in building patios and setting up fence posts, ensuring durability. Concrete manufacturers typically sell by volume, so you must calculate an estimate in cubic yards. Many find concrete takeoff daunting, but the process is straightforward.
Over-estimating the required quantities of concrete may result in an inflated bid price, and you will likely lose your bid. On the other hand, if you underestimate the amount of concrete required, you could win the bid but lose profitability. Inaccurate concrete takeoff numbers lead to waste and delays.
Ensure your takeoff estimate is accurate by first understanding the complete takeoff process end-to-end. The right knowledge will help you develop a takeoff estimate, ensuring efficiency and profitability.
Table of Contents
What is concrete takeoff?
Concrete takeoff involves four steps, estimating materials, estimating labor and equipment, and calculating overheads and profits.
The amounts will vary for slabs, foundations, and other concrete structures. Therefore, there is no one-fits-all formula to cover an entire project and you must rely on the structural drawings.
The engineer’s certified structural drawings provide all the details you need for an accurate estimate. However, they may not be available when bidding for a tender. In such cases, you may have to pay an additional amount.
How to do a concrete takeoff
There are generally twenty-one work areas to estimate before starting any concrete project. The contractor should estimate the 21 areas systematically to ensure an accurate takeoff. However, most projects do not require all 21 areas, so you can skip the areas you do not need.
The concrete takeoff workflow follows the below flow:
- Column footings
- Wall footings
- Foundation walls
- Piers below grade
- Building slabs on fill
- Exterior columns
- Interior columns
- Exterior beams
- Interior beams
- Shortened flat slabs
- Metal pan slabs
- Slabs on corrugated formwork
- Stairs on fill
- Shored stairs
- Stair landings
- Pan fill stairs
- Miscellaneous concrete in building
- Exterior sidewalks
- Exterior paving
- Exterior straight curbs
- Exterior curb & gutter
Note that the list above is complete of the areas to be covered but is not always applicable. Every project is different.
In concrete takeoffs, you first need to outline the area you need the concrete to go and take the structure’s measurements. Calculate the surface area of the structure, and determine the depth of the structure. Compute the volume of the structure and write down the product.
Calculate the cost of materials carefully by finding the correct measurements and quantities. It is important to get an accurate estimate of materials and their cost because this will affect your final numbers. Your materials estimate can make or break your bid.
The list above should guide key decisions. Review the plan carefully, starting from the bottom of every corner, and work systematically from one level to the next. Be careful with every piece of rebar and every square foot of rebar.
Once the required materials are ready, you can estimate the type and amount of concrete required for the project. Compile a list to ensure you do not miss anything.
Measure one area at a time, for example, slabs, wall foundations, foundation walls, and column foundations. Next, calculate the volume of concrete required for an area by multiplying the length by the width and depth. Then, add about 10% of the total volume to cover the additional cost of waste and spillage.
Determine the amount of concrete bags you will require by multiplying the total cost by the bag.
To complete your material estimate, calculate the additional materials you will need besides concrete. Factor in the cost of the equipment you will need. You may need equipment such as mixers, wheelbarrows, screeds, compactors, saws, polishers, vapor retarders, levels, groove cutters, floats, brooms, rubber boots, and edgers.
Complete a full calculation of the required materials and associated costs. You can use a pen and paper to mark areas on the plan as you complete the count. However, invest in professional estimating software or hire an estimating service to avoid errors.
Once you have estimated the materials, you must estimate the labor required to complete the job. Consider the cost of the projected labor. Also, consider overtime, travel time, wages (union vs. non-union), shift differences, and other building aspects.
Use average numbers to inform your calculations, not the fastest worker. The average worker can complete 300-350 square feet of concrete work daily. Remember to factor in the cost of mixing, transportation, compaction, reinforcement, formwork, and skilled labor.
The next step is to add costs. General expenses are all costs not related to direct labor, materials, or production, such as Back office operations, fleet, maintenance, advertising, and other expenses.
Consider the preparation time for client meetings and quotes! That's all you need to download. Calculating the initial cost can be confusing, but it's not that hard.
First, you need to know your overall expenses for the year. Include all wages for those working in the backend of the business, such as accountants and secretaries.
For larger general expenses, such as renting a work car or truck, you can also prorate the cost and include it as a specific startup cost. For example, if your company owns a truck you use regularly and plans to use for ten years, your annual cost will be 10% of the truck's total cost.
Knowing your total annual costs, you can also decide on a percentage for the year to spend on a particular project and factor that percentage into your specific cost estimate. If a particular job is a large, 4-week project and typically works 50 weeks per year, the current estimate should include 8% of the total cost.
The next step, of course, is to make a profit. In addition to expenses, how much can you earn in a year? If you want your business to stay afloat, you'll need to include your markup in the final launch.
To calculate profit, start by determining your company's overall profit margin (typically 2-10% in the construction industry), then add that annual gross profit percentage, as you did for general expenses. Get a raise.
Of course, you should not include the "cost" and "profit" parts when writing the final quote, estimate, or offer. Instead, restructure these costs into labor costs during the final physical launch.
Many consider concrete takeoff daunting because it can affect your chances of winning a bid or making a profit. Accurate concrete takeoff helps ensure your estimate delivers a winning but profitable bid. Concrete takeoff is a straightforward process once you have understood how it works end-to-end.
Since errors are likely to occur, it is best to use takeoff software when preparing your concrete takeoff.
Additionally, you can contact a professional estimating service to avoid errors. These errors could affect your bid or profitability.
Concrete takeoff is important because overestimating can cause inflated prices while underestimating will cause losses. Contractors must understand how to calculate concrete takeoff accurately, following the 21 steps and calculating in cubic yards.