One basic essential for estimating a roof replacement job is being able to determine how many shingles the job will require. When homeowners call for roofer services, they want the most precise estimate possible, so it is important to know how to accurately judge the cost of materials based on requirements. To avoid under-estimating a job or overestimating and buying too many shingles, the formula below can be used to figure the right numbers.
Methods to Measure for Count
There are three methods that roofer services typically use to decide on how many shingles they need to use for any replacement job as follows:
- Measurement - This is the simplest way to ascertain the amount of shingles needed for a job and involves measuring to determine the total square footage of the entire roof. This can sometimes be difficult if the roof is steep. Pane lengths can also be taken from the ground, but there is still a need to measure the pitch from the ridge to eaves and rakes to complete the measurements.
- Sheet Count - The sheet count method involves simply counting the number of decking sheets used on the entire roof. This technique can be used safely and easily from the ground when the decking sheets are still exposed. Standard decking sheets are 32 square feet. Count the number of sheets used and multiply that figure by 32 to determine total roof square footage.
- Shingle Count - This count technique is another easy way for roofer services to determine total square footage from the ground when shingles are still present on the roof. Measure the length of the eaves (including any rakes) of the roof pane from the ground to determine length. Next, count the number of rows of each individual roof covering from the eaves to the ridge. With a 5-inch exposure, multiply the number of rows by 5, then divide by 12 to reduce that number to feet. Multiply this number by the pane length to determine how many shingles are required for that pane. Be warned that this method works for standard 3-tab shingles with average exposure. Adjust estimates as necessary when calculating using different sized versions.
Other Roof Areas
Besides measuring the roof panes, careful estimation of shingle requirements for a roof replacement must also take other areas into consideration. Ridge and hip caps as well as valleys all require additional units that must be included. Rake edges and starter shingles along all panes must also be included in calculations. More complicated roofs that have many angles involve breaking those angles down into rectangles and triangles, then calculating shingle need area-by-area.
By considering pane measurements and all additional sizing factors, roofer services can carefully calculate the total square feet of a roof. Based on this calculation and the number of shingles per square for the specific ones being used, it is possible to determine the number of squares required for a replacement job. Adding an extra square or two just allows contractors to accurately estimate roof replacement jobs for their customers!
