The answer to 'how much does underlayment cost' is that the cost of roofing underlayment can vary significantly depending on several factors. Underlayment is an essential component of a roof system, providing a critical barrier between the roof deck and the outer roofing material.
The cost of underlayment is influenced by the type of material (asphalt-based, synthetic, or rubberized), the thickness and quality, and the square footage required for your roof. Generally, you can expect to pay anywhere from $0.50 to $2 per square foot for basic underlayment, with higher-end options costing more. The total cost will depend on the size of your roof and the specific underlayment you choose.