Get the square footage of roof and divide it by 100 and it will give the number of squares you need and for every decimal number over 3 buy a bundle to achieve the amount of material.
How many squares does my roof have.
To find the squares divide the overall roof area by 100 and then round up.
Singles are often sold in bundles with three bundles equaling one roof square.
For instance if the roof is 1550 square feet then it is 16 squares.
1square of roofing covers 100 square feet of roof a bundle is 1 3 of a square.
Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.
A square of shingles is the number of shingles needed to cover 100 sq feet of roof area.
Shingle roofs typically have a life span of 15 30 years while membrane roofs usually last 5 15 years.
A square simply refers to a 10 x 10 square of roofing.
How to estimate roofing materials.
Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.
To determine the number of squares on the gable roof above simply divide its total of 24 000 square feet by 100.
If your roof is flat or has no more than a 3 in 12 pitch you can calculate its total square footage by simply multiplying the length by the width.
As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.
The result is 240 and this means you would need 240 squares of shingles to cover that roof.
Steep roofs measure your house at ground level then add in the roof s overhang for greater accuracy.
It is often compared to slope but is not exactly the same.
Although roofing projects are estimated and sold by the square roofing material is often not sold in 1 square increments.
Check that your footage measurements are within this range so you can start off on the right foot.
Estimate the pitch of the roof.
When figuring the amount of shingles needed to roof a house you first convert the total square footage of the roof to squares a square represents 100 square feet of area covered by shingles.
A square is an area of roof which measures 100 square feet.
Because each 100 square feet of roof is one roofing square divide the total area from step 1 by 100.
For a new roof you will also need the same amount of underlayment.
The most common type of shingle called a three tab or strip shingle is generally packaged three bundles per square.
Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure.
They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design.
As a rule of thumb there are 3 bundles to a square assuming that you are using three tab strip shingles.
This is simply 100 square feet of roof.
