The Gambrel Roof Underlayment and Cost calculator computes the total surface area of a gambrel roof for underlayment based on the dimensions below and the estimated cost based on the area and unit price of underlayment material.
INSTRUCTIONS: Choose units and enter the following:
- (L) Ridge Length
- (S) Span of Roof
- (P1) Lower Pitch
- (P2) Upper Pitch
- (AH) Attic Height
- (oH) Overhang
- (UP) Unit Price of Underlayment
Gambrel Roof Underlayment and Cost (TC): The calculator returns the surface area for underlayment in square feet and the total cost of underlayment in U.S. dollar. However, these can be automatically converted to compatible units via the pull-down menu.
The Math / Science
The surface area of a gambrel roof is easy to compute based on the span, ridge length, overhang, attic height and two pitches of the roof. This calculator uses those specifications to compute the surface area of the roof. Once the surface area is known, the unit pricing (cost per square foot of underlayment) can be easily applied.
Underlayment comes in different types of materials and in different sizes of products measured in square feet. To compute the Unit Price per Square Feet CLICK HERE. A pop-up calculator will let you enter the product size (e.g., 265 square feet) and the total cost and will return the dollars per square feet.
Underlayment Pricing Data
The underlayment pricing data contains the following information in each record.
- Underlayment Pricing Survey Date: 1/2/23
- Underlayment Pricing Survey Store: Lowes
- Price of Felt Underlayment: $0.12 USD/ft²
- Price of Polypropylene Underlayment: $0.36 USD/ft²
- Paper (red rosin) Underlayment: $0.03 USD/ft²
- Rubber Underlayment: $0.95 USD/ft²
- Rubberized Asphalt Underlayment: $0.61 USD/ft²
- Synthetic Underlayment: $0.08 USD/ft²
All pricing is in U.S. dollars per square feet of underlayment.
IMPORANT NOTE
All pricing in vCalc is for use by our community to provide rough estimates on project costs. One should always use local pricing for the most accurate pricing available. Price surveys are based on listed prices on the websites of the companies listed and only periodically updated at this time. The product retailer surveyed is randomly selected. No assertions or recommendations are made on retailer reliability, service quality or product value, availability or any other implied guarantees. This is simply a price survey to help with rough estimates and the math of construction.
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