Measure Your House for Fiber-Cement Siding

Use this quick guide for measuring your house for fiber-cement siding.

You Will Need:

• Buy or borrow a 50-foot or greater tape measure and a “wide” 25-foot tape measure such as the Stanley FatMax.

• Painter’s telescoping aluminum pole (optional).

• Calculator

• Pencil and paper.

Step 1:    Measure Area of Square or Rectangular Portions of Wall

With the 50-foot measuring tape, measure the height and width of square or rectangular parts of your exterior walls.  Multiply length by width to get area.

In the example shown to the left, the height is 10 feet and the width is 30 feet.  So, the area is 300 square feet.

Step 2:    Measure Area of Triangular Portions of Wall

With the “wide” tape measure, measure the triangular portions of the walls.  Since the triangular portions are ten feet high or greater, the “wide” tape measure provides the stability you need to push the tape measure up to their heights.  As an alternative, you can fix the end of the tape measure to a telescoping aluminum painter’s pole and push it up that way.

Multiply width by 1/2 of the height to get the area.  In the example, the width is 30 feet.  The height of the triangle is 10 feet.  30 x (1/2 x 10) = 30 x 3 = 90.  So the area of the triangular portion of this wall is 90 square feet.

Step 3:    Measure Dormers and Other Odd Parts of Exterior

Measure the odd-sized parts of the exterior such as dormers.

Here, the area of the dormer is 6 square feet.

Step 4:    Measure Area of Windows and Doors

In our example, the area of the windows and doors is 20 square feet.

Step 5:    Arrive at Total Area of Wall

Add measurements of Step 1 + Step 2 + Step 3.  Subtract measurement from Step 4 (since you will not be siding the windows or doors).

So, in our example:  300 + 90 + 6 – 20 =  376 square feet.

Step 6:    Measure Rest of Walls and Arrive at Total Square Footage of House

Repeat these steps for the rest of the house.  Add all amounts to get a total square footage for your house.

Step 7:    Add in 10% Wastage

You will need to buy more vinyl siding than is actually used to allow for wastage.  Wastage is where the ends of siding are cut off to make a perfect fit.  These waste ends can sometimes be reused in other places, sometimes not.  Take the total square footage of the house, multiply by .10 on the calculator.  The amount shown on the calculator is your wastage amount.  Add the wastage amount to the total you have at this point.

Step 8:     Divide Everything by 100 to Find Number of “Squares”

Siding companies and manufacturers speak in terms of “squares.”  A square is 100 square feet of siding material.  They generally do not talk in terms of individual square feet because the measurements they are dealing with are so large.

So, for our example:  the total wall area for the house is 3200 square feet.  Divide 3200 by 100.  The siding installer will use 32 squares of siding material on the house.