How to Bid a Roofing Job: A Step-by-Step Guide to Roofing Estimates

1. Get clear on the scope of work

Make sure you understand what the job entails by visiting the site, talking to the client, measuring and surveying the roof, and being aware of the building codes in your area.

Speak to your client

Speak directly with the client, either on the phone or in person. Ask as many questions as you need to better understand their wants and needs: What kind of home is it? What are their expectations? What is their budget?

Clients may also specify what type of roof they want, such as tile or wood shingles. In that case, your job is simple—follow their requests.

However, if their preference isn’t the best option due to things like climate or building code, you should provide educated recommendations and include multiple price estimates and ranges for different materials.

Review building codes

Certain building codes will restrict what materials you can use. For example, enclosed housing estates often dictate that you use certain materials and colors to ensure all houses are uniform.

Environmental factors can also contribute to building codes, with some regions dictating what material can be used to endure certain weather conditions.

Survey the roof

Carefully inspect the roof to further understand the scope of the work and identify any additional areas that may require more labor and/or material costs. 

When surveying the roof, look for:

• Any roof damage
• Condition of the roofing shingles, including how many layers there are
• Eaves, valleys, hips, and ridges condition
• Blocked vents, chimneys, plumbing vents, and skylights
• Cracked or damaged flashing
• Other special elements like solar panels or satellite dishes

Take photos and detailed notes of these areas. You can attach them to your client’s profile for future reference.

2. Measure the roof

Measuring the roof helps you determine the number of squares to install for your largest material cost: your roofing material. Follow these 3 steps to calculate how many squares to install.

Note: In standard roofing terminology, 1 square = 100 square feet.

Calculate the number of ground-level squares

Take the external dimensions of the house and divide it by 100.

For example, if you’re working on a house that is 30 ft. x 60 ft., then the entire area is 1800 square feet (30*60). Divide that number by 100 to arrive at 18 ground-level squares.

This is just the flat area. Most homes are pitched, and you’ll have to account for that in the next step.

Determine the roof pitch

The roof pitch, or how steep it is, is expressed as a ratio.

A ratio of 4:13, for instance, means the roof rises 4 feet for every 13 feet of horizontal length. The roof pitch can either be low, medium, or high.

A low roof pitch has a ratio of 5:12 or lower, a medium roof pitches 6:12 to 9:12, and a high roof pitches 10:12 to 12:12.

For our example, let’s assume the roof pitch is 5:12.

Determine your roof pitch multiplier 

The final step is to multiply the number of ground level squares by a pitch multiplier.

Use the roof pitch multiplier chart below to determine the correct number:

3. Estimate material cost

Now that you have a firm grasp on what the job entails, list the materials you need and calculate the total cost. Keep in mind that due to an increase in raw material costs and rising demand, the cost of construction materials is increasing.

Although asphalt shingles are the most common roofing material, you also have the option of other roofing materials such as solar tiles, metal roofing, stone-coated steel, slate, rubber slate, and even green roofs with plants on them.

Regardless of what material you choose, ensure you contact your supplier for the cost per square foot. While exact prices for roofing material will differ between suppliers and the type of roofing material, expect to pay anywhere from $3.50 to $6 per square foot for asphalt shingles.

Let’s assume you’re installing asphalt shingles at the cost of $4.00 per square foot for the 23-square house in our example. Your total material cost is now $9,200.00 (2,300*$4.00).

Don’t forget to tally the cost of all your other materials: nails, flashing, underlayment, and vents. For our running example, let’s use a cost of $700 for all these materials, which brings your total material cost to $9,900.00 ($9,200.00 + $700).

4. Estimate labor costs

With your material costs calculated, it’s time to estimate labor cost. You can calculate your total labor cost by following this process:

• Determine the labor hours. Estimate how many hours the job will take and multiply this figure by the number of employees on the job. This calculation will give you the number of labor hours. For example, assuming it takes two people 40 hours to complete the job, your labor hours will be 80.
• Work out your hourly labor cost. When calculating your hourly labor cost, consider both the hourly wage and extras like taxes and worker’s compensation. The average hourly rate for a roofing contractor in the U.S. is $17.95.  For our example, let’s add 20% for taxes and insurance, which brings the total hourly wage to $21.54.
• Calculate the total labor cost. Multiply the labor hours by the hourly wage for a total labor cost of $1,723.20 ($21.54*80).

5. Calculate your overhead costs

Your overhead costs are all the ongoing expenses that keep your business up and running, like uniforms, office rent, insurance, roofing tools, and operations software like Jobber.

The price you charge for the roofing job must cover these overheads for your business to be profitable.

Here’s a four-step process to ensure you’re recouping overheads on every roofing job:

• Calculate your overhead cost for per week (let’s assume this number is $900.00)
• Calculate your weekly labor hours (for example, 90)
• Divide the hours into the overhead costs for an hourly figure ($900/90=$10). This means that for every labor hour you need to charge $10 to cover your overhead costs.
• Multiply the hourly figure by the number of labor hours for the current job to determine what to charge to recover your costs. For our example, we’ll multiply $10 by 80 hours to arrive at $800.

6. Tally all roofing costs

Add up all your costs for a total roofing job cost:

• Material: $9,900.00
• Labor: $1,723.20
• Overhead: $800.00
• Total costs: $12,423.20

7. Add your markup for desired profits

Until now, you’ve been estimating how much you’ll need to break even on the cost of doing the roofing job. But you’re not here to work for free.

The final step is to add your markup so you can turn a profit.

What is roofing markup?

Your markup is the amount you add to the cost of your services to realize a profit. Markup is usually expressed as a percentage. 

The formula is: (Profit / Cost)*100.

The markup percentage you choose to add to your break-even cost price will depend on your desired profit margin. That is, how much profit you want to earn for this job. 

The formula to determine your margin is: (Profit / Sales)*100.

A decade ago, the average profit margin for roofing jobs was 6%, but that has since grown and a target of 15-20% is standard across various industries. 

How do you apply markup to your roofing bid?

In order to achieve your desired margins, you need to markup your break-even cost by a percentage greater than your margin. For our example, if you want a 13% margin, you’ll need to add a 15% markup.

This gives you a final price of $14,286.68 ($12,544.80*1.15) for the roofing job, and a profit of $1,863.48 ($14,426.52 – $12,423.20).

8. Create your roofing bid

Arriving at an accurate price for your roofing jobs is half the battle won. You now need to create a professional bid to convince customers you’re the best person for the job.