How to Measure for Soffit?

To measure for the amount of soffit board you need, you will calculate the total area by considering the length of the walls and the width of the eaves, adding extra for waste.

Calculating the Soffit Area Needed

Measuring for soffit primarily involves determining the total square footage or square metres required to cover the underside of your roof eaves. This calculation helps ensure you purchase enough material for the job.

According to the reference, you should:

1. Calculate the total length of all of the walls where soffit will be installed. This means measuring the length of each section of wall under the eaves and adding them together.
2. Measure the width of the eaves gap. This is the horizontal distance from the side of the house wall out to the fascia board (the vertical board at the edge of the roof).
3. Add 10% to your calculated length. This crucial step accounts for potential cutting errors, damage during handling or installation, and general waste. You should increase the total length you calculated in step 1 by 10%.
4. Multiply the adjusted total length by the width of the eaves gap. The result will give you the total square feet or square metres of soffit board required.

Formula:

Soffit Area Needed = (Total Length of Walls + 10% Waste) × Width of Eaves Gap

Or, more precisely:

Soffit Area Needed = (Total Length of Walls × 1.10) × Width of Eaves Gap

Step-by-Step Measurement Process

Here’s a simple breakdown of how to measure:

• Measure Wall Lengths: Use a tape measure to find the length of each wall segment that has an eave requiring soffit. Walk around the house and measure each side or section individually. Note these measurements down.
• Sum Wall Lengths: Add all the individual wall lengths together to get the total perimeter length where soffit is needed.
• Measure Eaves Width: At several points along the eaves, measure the distance from the exterior wall surface straight out to the fascia board. This width should be relatively consistent around the house. Use the widest measurement if there are slight variations.
• Apply Waste: Take your total calculated wall length and multiply it by 1.10 (which is adding 10%).
• Calculate Total Area: Multiply the waste-adjusted total wall length by the eaves width measurement. This final number is the square footage (if using feet) or square metres (if using metres) of soffit material you should purchase.

Example Calculation

Let's say you have a simple rectangular house:

• Wall 1: 40 feet

• Wall 2: 25 feet

• Wall 3: 40 feet

• Wall 4: 25 feet

• Total Length of Walls: 40 + 25 + 40 + 25 = 130 feet

• Width of Eaves Gap: Let's say this measures 1.5 feet

Using the formula based on the reference:

1. Add 10% Waste to Length: 130 feet * 1.10 = 143 feet (This is your waste-adjusted length)
2. Calculate Area: 143 feet * 1.5 feet = 214.5 square feet

In this example, you would need approximately 214.5 square feet of soffit board.

Tracking Your Measurements

Using a simple table can help keep track of your measurements:

Wall/Section	Length (ft/m)	Eaves Width (ft/m)	Notes (e.g., around chimney)
Front Wall	40	1.5
Side Wall 1	25	1.5
Back Wall	40	1.5
Side Wall 2	25	1.5
Total	130	(Use widest)

Always double-check your measurements before ordering materials. It's better to have a little extra than not enough, especially with the recommended 10% waste factor already included in the calculation method from the reference.