Roof Tarp Calculator

Last updated: 12 Jun 2025 | Author: Brij | Review By: Irshad

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The Roof Tarp Calculator is a quick and easy tool designed to help you estimate the amount of tarp needed to cover your roof. By simply entering your roof area, this calculator provides an accurate tarp requirement.

Roof Length:

Roof width:

Overlap Length:

Result

Roof Area:

Roof trap:

To estimate the tarp size for your roof. Simply enter the roof's base length, width, and desired overlap, and the calculator will provide the total tarp area required to ensure complete and secure coverage.

What is roof trap?

A Roof Tarp is a protective covering, usually made from waterproof material, used to temporarily shield a roof from weather damage, leaks, or debris. It is often used after storms, during roof repairs, or to prevent water infiltration until permanent fixes are made.

Step-by-Step Process to Find Tarp Area:

Step 1: Calculate Roof Area (A)

The roof area is typically calculated by multiplying the length by the width of the roof base. For a simple rectangular or square roof:

$\text{Roof Area (A)} = \text{Length (L)} \times \text{Width (W)}$

Step 2: Calculate Roof Perimeter (P)

The perimeter of the roof is the total length around the base of the roof, calculated as:

$\text{Perimeter} = 2 \times (\text{Length} + \text{Width})$

Step 3: Calculate Tarp Area

Now, to account for the extra overhang (to secure the tarp around the edges of the roof), we use the formula:

$\text{Tarp Area} = \text{Roof Area} + (\text{Overlap Length} \times \text{Perimeter})$

Example Calculation:

Let’s assume:

Roof Base Length (L) = 40 feet.
Roof Base Width (W) = 30 feet.
Overlap Length = 2 feet (for securing the tarp).

Step 1: Calculate Roof Area (A)

$\text{Roof Area (A)} = \text{40} \times \text{30}$

$\text{Roof Area (A)} = 1200 \text{ square feet}$

Step 2: Calculate Roof Perimeter (P)

$\text{Perimeter (P)} = 2 \times (\text{40} + \text{30})$

$\text{Perimeter (P) } = \text{ 140 feet}$

Step 3: Calculate Tarp Area

Now, using the formula for Tarp Area:

$\text{Tarp Area} = \text{1200} + (\text{2} \times \text{140})$

$\text{Tarp Area} = 1,480 \text{ square feet}$

So, the total tarp area required to cover the roof, including a 2-foot overhang, is 1,480 square feet.

FAQs

1. How long can a roof tarp stay on?

While roof tarps are meant for temporary protection, high-quality tarps properly installed can last up to 90 days. However, it’s recommended to replace them with permanent roofing solutions as soon as possible.

2. What size tarp do I need to cover my roof?

The tarp size depends on the area of damage and how much overhang is needed to secure it. Always choose a tarp that is at least 3–4 feet larger than the damaged area on all sides to allow for proper anchoring and water runoff protection.