Spray Foam Insulation Calculator
This calculator helps you estimate the amount of spray foam insulation needed for your project and its approximate cost. Spray foam insulation is a highly effective insulator that expands to fill gaps and cracks, providing an excellent air seal and thermal barrier. It's commonly used in attics, crawl spaces, basements, and walls.
Understanding Spray Foam Insulation
Spray foam insulation offers superior performance compared to traditional insulation materials like fiberglass or mineral wool. Its ability to create a monolithic barrier against air and moisture infiltration significantly improves energy efficiency, leading to lower heating and cooling costs. There are two main types:
- Closed-Cell Spray Foam: Denser and more rigid, it has a higher R-value per inch and acts as a vapor barrier. It's ideal for applications requiring structural reinforcement or where moisture resistance is critical, such as basements or rim joists. It typically yields about 0.5 board feet per pound (or is priced per board foot).
- Open-Cell Spray Foam: Softer and more flexible, it has a lower R-value per inch but offers excellent sound dampening properties and is more permeable to vapor. It's often used in attics, walls, and for soundproofing. It typically yields about 1.0 board foot per pound (or is priced per board foot).
Board Foot: A board foot is a unit of volume used in the insulation industry, equal to one square foot of area that is one inch thick. Calculation: (Length in feet * Width in feet * Thickness in inches) / 12.
Waste Factor: It's important to account for material waste during installation. A waste factor of 10-15% is common.
function calculateSprayFoam() { var length = parseFloat(document.getElementById("areaLength").value); var width = parseFloat(document.getElementById("areaWidth").value); var height = parseFloat(document.getElementById("areaHeight").value); var wastePercentage = parseFloat(document.getElementById("wasteFactor").value); var foamTypeSelect = document.getElementById("foamType"); var selectedFoamType = foamTypeSelect.value; var foamTypeOption = foamTypeSelect.options[foamTypeSelect.selectedIndex]; var yieldPerBoardFoot = parseFloat(foamTypeOption.getAttribute("data-yield-per-board-foot")); // This is a proxy for price per board foot in this simplified model var resultDiv = document.getElementById("result"); resultDiv.innerHTML = "; // Clear previous results if (isNaN(length) || isNaN(width) || isNaN(height) || isNaN(wastePercentage) || length <= 0 || width <= 0 || height <= 0 || wastePercentage < 0) { resultDiv.innerHTML = 'Please enter valid positive numbers for all fields.'; return; } // Calculate total area in square feet var totalAreaSqFt = length * width; // Calculate total board feet needed var totalBoardFeet = (totalAreaSqFt * height) / 12; // Account for waste var wasteAmount = totalBoardFeet * (wastePercentage / 100); var totalBoardFeetWithWaste = totalBoardFeet + wasteAmount; // Calculate approximate cost var approximateCostPerBoardFoot = 0; if (selectedFoamType === "closedCell") { approximateCostPerBoardFoot = 0.50; // Cost per board foot for closed cell } else if (selectedFoamType === "openCell") { approximateCostPerBoardFoot = 0.35; // Cost per board foot for open cell } var approximateTotalCost = totalBoardFeetWithWaste * approximateCostPerBoardFoot; resultDiv.innerHTML = `