Metal Roof Calculator for Hip Roof
Use this calculator to estimate the materials and costs for installing a metal roof on a hip-style roof. A hip roof is characterized by all sides sloping downwards to the walls, usually with a consistent pitch, forming a ridge at the top for rectangular buildings or meeting at a single peak for square buildings. Metal roofing offers exceptional durability, energy efficiency, and a modern aesthetic, making it a popular choice for hip roofs.
How to Use the Calculator:
- Enter the overall length and width of your building's footprint in feet.
- Input the roof pitch as a "rise" value (e.g., for a 4/12 pitch, enter '4').
- Specify the coverage width of your chosen metal panels in inches.
- Provide an estimated waste factor (e.g., 10 for 10%) to account for cuts and errors.
- Enter the estimated costs per square foot for metal panels, underlayment, and fasteners.
- Input the estimated costs per linear foot for hip/ridge trim and eave trim.
- Optionally, add your estimated labor cost per square foot of roof area.
- Click "Calculate" to get your material quantities and estimated total project cost.
Understanding Hip Roof Metal Roofing
A hip roof is a type of roof where all sides slope downwards to the walls, usually with a gentle slope. This design makes them very stable and resistant to wind, which is a significant advantage in many climates. When combined with metal roofing, a hip roof offers an exceptional blend of aesthetics, durability, and performance.
Why Choose Metal for a Hip Roof?
- Durability: Metal roofs can last 40-70 years, significantly outperforming traditional asphalt shingles. They are resistant to fire, rot, insects, and mildew.
- Wind Resistance: The inherent stability of a hip roof, combined with the robust fastening systems of metal panels, makes them highly resistant to high winds.
- Energy Efficiency: Many metal roofing materials are designed with reflective coatings that can reduce cooling costs by reflecting solar radiant heat.
- Aesthetics: Metal roofing comes in a wide array of colors, finishes, and profiles (e.g., standing seam, corrugated), allowing for a custom look that complements the architectural style of a hip roof.
- Low Maintenance: Once installed, metal roofs require minimal maintenance compared to other roofing materials.
Factors Affecting Cost:
- Roof Pitch: Steeper pitches require more material and can increase labor costs due to safety equipment and difficulty of installation.
- Roof Complexity: While hip roofs are generally straightforward, the number of dormers, skylights, or other penetrations can add to material and labor costs.
- Metal Panel Type: Different metals (steel, aluminum, copper, zinc) and panel profiles (standing seam, corrugated, stone-coated) have varying price points.
- Trim and Accessories: Hip and ridge caps, eave and rake trim, fasteners, sealants, and snow guards all contribute to the overall cost.
- Underlayment: High-quality synthetic underlayments or ice-and-water shield membranes add to material costs but provide superior protection.
- Labor Rates: Installation costs vary significantly by region and the experience of the roofing contractor. Metal roof installation requires specialized skills.
- Waste Factor: Hip roofs, with their multiple angles and cuts, often have a higher waste factor than simple gable roofs.
Important Considerations:
- Local Building Codes: Always check with your local authorities for specific requirements regarding roofing materials and installation.
- Ventilation: Proper attic ventilation is crucial for the longevity of your roof and energy efficiency, especially with metal roofing.
- Contractor Experience: Choose a roofing contractor with proven experience in installing metal roofs on hip-style structures.
- Warranty: Understand the manufacturer's warranty on the metal panels and the contractor's warranty on the installation.
function calculateMetalRoofCost() {
// Get input values
var buildingLength = parseFloat(document.getElementById("buildingLength").value);
var buildingWidth = parseFloat(document.getElementById("buildingWidth").value);
var roofPitchRise = parseFloat(document.getElementById("roofPitchRise").value); // e.g., 4 for 4/12
var panelCoverageWidth = parseFloat(document.getElementById("panelCoverageWidth").value); // inches
var wasteFactor = parseFloat(document.getElementById("wasteFactor").value) / 100; // convert to decimal
var panelCostPerSqFt = parseFloat(document.getElementById("panelCostPerSqFt").value);
var hipRidgeTrimCostPerLinFt = parseFloat(document.getElementById("hipRidgeTrimCostPerLinFt").value);
var eaveRakeTrimCostPerLinFt = parseFloat(document.getElementById("eaveRakeTrimCostPerLinFt").value);
var underlaymentCostPerSqFt = parseFloat(document.getElementById("underlaymentCostPerSqFt").value);
var fastenerCostPerSqFt = parseFloat(document.getElementById("fastenerCostPerSqFt").value);
var laborCostPerSqFt = parseFloat(document.getElementById("laborCostPerSqFt").value);
// Validate inputs
if (isNaN(buildingLength) || buildingLength <= 0 ||
isNaN(buildingWidth) || buildingWidth <= 0 ||
isNaN(roofPitchRise) || roofPitchRise <= 0 ||
isNaN(panelCoverageWidth) || panelCoverageWidth <= 0 ||
isNaN(wasteFactor) || wasteFactor < 0 ||
isNaN(panelCostPerSqFt) || panelCostPerSqFt < 0 ||
isNaN(hipRidgeTrimCostPerLinFt) || hipRidgeTrimCostPerLinFt < 0 ||
isNaN(eaveRakeTrimCostPerLinFt) || eaveRakeTrimCostPerLinFt < 0 ||
isNaN(underlaymentCostPerSqFt) || underlaymentCostPerSqFt < 0 ||
isNaN(fastenerCostPerSqFt) || fastenerCostPerSqFt < 0 ||
isNaN(laborCostPerSqFt) || laborCostPerSqFt < 0) {
document.getElementById("result").innerHTML = "
Please enter valid positive numbers for all fields.
";
return;
}
// — Calculations —
// 1. Slope Factor
// Slope Factor = sqrt(rise^2 + 12^2) / 12
var slopeFactor = Math.sqrt(Math.pow(roofPitchRise, 2) + Math.pow(12, 2)) / 12;
// 2. Total Roof Surface Area (Sq Ft)
// For a rectangular hip roof, a common approximation for total surface area for material estimation
// is (Building Length * Building Width) * Slope Factor.
// This accounts for the increased surface due to pitch.
var roofArea = buildingLength * buildingWidth * slopeFactor;
var adjustedRoofArea = roofArea * (1 + wasteFactor);
// 3. Trim Lengths
var ridgeLength = 0;
var singleHipLength = 0;
var totalHipLength = 0;
// Determine ridge and hip lengths based on building dimensions
if (buildingLength > buildingWidth) {
// Rectangular footprint with a ridge along the longer dimension
ridgeLength = buildingLength – buildingWidth;
// Hip run in plan view for the triangular ends (diagonal from corner to ridge end)
var hipRunPlan = Math.sqrt(Math.pow(buildingWidth / 2, 2) + Math.pow(buildingWidth / 2, 2));
// True hip length (each of the 4 hips)
singleHipLength = hipRunPlan * slopeFactor;
totalHipLength = 4 * singleHipLength;
} else if (buildingWidth > buildingLength) {
// Rectangular footprint with a ridge along the longer dimension (width > length)
ridgeLength = buildingWidth – buildingLength;
// Hip run in plan view for the triangular ends (diagonal from corner to ridge end)
var hipRunPlan = Math.sqrt(Math.pow(buildingLength / 2, 2) + Math.pow(buildingLength / 2, 2));
// True hip length (each of the 4 hips)
singleHipLength = hipRunPlan * slopeFactor;
totalHipLength = 4 * singleHipLength;
} else {
// Square footprint, hips meet at a single peak, no ridge
ridgeLength = 0;
// Hip run in plan view (diagonal from corner to center)
var hipRunPlan = Math.sqrt(Math.pow(buildingLength / 2, 2) + Math.pow(buildingWidth / 2, 2));
// True hip length (each of the 4 hips)
singleHipLength = hipRunPlan * slopeFactor;
totalHipLength = 4 * singleHipLength;
}
var totalHipRidgeTrimLength = ridgeLength + totalHipLength;
// Eave Trim Length (Perimeter of the building footprint)
var eaveTrimLength = (2 * buildingLength) + (2 * buildingWidth);
// 4. Material Costs
var metalPanelMaterialCost = adjustedRoofArea * panelCostPerSqFt;
var hipRidgeTrimMaterialCost = totalHipRidgeTrimLength * hipRidgeTrimCostPerLinFt;
var eaveTrimMaterialCost = eaveTrimLength * eaveRakeTrimCostPerLinFt;
var underlaymentMaterialCost = adjustedRoofArea * underlaymentCostPerSqFt;
var fastenerAccessoryCost = adjustedRoofArea * fastenerCostPerSqFt;
var laborCost = roofArea * laborCostPerSqFt; // Labor usually based on actual roof area, not adjusted for waste
// 5. Total Estimated Project Cost
var totalEstimatedProjectCost = metalPanelMaterialCost + hipRidgeTrimMaterialCost + eaveTrimMaterialCost +
underlaymentMaterialCost + fastenerAccessoryCost + laborCost;
// — Display Results —
document.getElementById("totalRoofArea").innerHTML = "
Total Roof Surface Area: " + roofArea.toFixed(2) + " sq ft";
document.getElementById("estimatedMetalPanelSqFt").innerHTML = "
Estimated Metal Panel Material (including waste): " + adjustedRoofArea.toFixed(2) + " sq ft";
document.getElementById("estimatedHipRidgeTrimLinFt").innerHTML = "
Estimated Hip/Ridge Trim: " + totalHipRidgeTrimLength.toFixed(2) + " linear ft";
document.getElementById("estimatedEaveTrimLinFt").innerHTML = "
Estimated Eave Trim: " + eaveTrimLength.toFixed(2) + " linear ft";
document.getElementById("estimatedUnderlaymentSqFt").innerHTML = "
Estimated Underlayment Material (including waste): " + adjustedRoofArea.toFixed(2) + " sq ft";
document.getElementById("metalPanelMaterialCost").innerHTML = "
Metal Panel Material Cost: $" + metalPanelMaterialCost.toFixed(2);
document.getElementById("hipRidgeTrimMaterialCost").innerHTML = "
Hip/Ridge Trim Material Cost: $" + hipRidgeTrimMaterialCost.toFixed(2);
document.getElementById("eaveTrimMaterialCost").innerHTML = "
Eave Trim Material Cost: $" + eaveTrimMaterialCost.toFixed(2);
document.getElementById("underlaymentMaterialCost").innerHTML = "
Underlayment Material Cost: $" + underlaymentMaterialCost.toFixed(2);
document.getElementById("fastenerAccessoryCost").innerHTML = "
Fasteners & Accessories Cost: $" + fastenerAccessoryCost.toFixed(2);
document.getElementById("laborCost").innerHTML = "
Estimated Labor Cost: $" + laborCost.toFixed(2);
document.getElementById("totalEstimatedProjectCost").innerHTML = "
Total Estimated Project Cost: $" + totalEstimatedProjectCost.toFixed(2);
}