# Calculate Exact Shingle Needs for Any Roof Size

As homeowners, we’ve all been there – standing in the roofing aisle, staring blankly at the stacks of shingle bundles, unsure exactly how many to purchase. Order too few, and you’ll need to make an extra trip back to the store, delaying your roofing project. Order too many, and you’ve wasted money on supplies you don’t need. So how do you determine the perfect shingle order for your specific roof?

Calculating the precise number of shingles required may seem complicated at first. But with a basic understanding of a few key roofing measurements, you can learn to determine exact shingle quantities like a pro. You’ll gain the skills and knowledge to calculate your needs accurately, avoiding wasted time, money, and materials.

## What is a Square in Roofing?

First, it’s helpful to understand the concept of a “square” in roofing terms. When it comes to shingles, a square refers to an area of 100 square feet. This unit of measurement originated years ago as a way for roofers to calculate materials quickly and easily. Though not an actual square shape, understanding what a square represents makes covering any roof area simple.

Knowing that a square equals 100 square feet is key for estimating shingle quantities correctly. Before ordering materials, you’ll need accurate measurements of your roof’s total square footage. Precision here is vital, as even small measurement errors can throw off your whole shingle order. So let’s look at how to systematically measure the square footage of each roof section.

## How to Measure Total Roof Square Footage

Measuring a roof’s square footage is easier with the right tools and preparation. Here are some tips for getting accurate measurements:

• Use an architectural drawing or satellite image to identify each rectangular section of roofing.
• For simple roofs, measure length x width of each section with a tape measure. Multiply to find square feet.
• For complex roofs, break into smaller manageable squares and triangles. Calculate each individually.
• Account for overhangs, valleys, dormers and other features separately.
• Double check all measurements – accuracy is critical.

Doing the legwork to get precise roof dimensions gives you a reliable total square footage amount. With this number, you can then determine the number of shingle bundles needed. But first, let’s look at how many square feet a typical shingle bundle covers.

## Shingle Bundle Coverage

When purchasing shingles, they come packaged together in bundles. Most shingle bundles, regardless of manufacturer or shingle type, cover an area of 33 square feet. Verifying the bundle coverage on the packaging is recommended, but you can generally rely on 33 square feet as the standard. Some key things to know:

• Each bundle contains enough individual shingles to cover 33 sq ft when installed.
• Bundle coverage is consistent across most shingle types and styles.
• Specialty shingles may have different bundle coverages – always verify.

Understanding how much area a bundle covers makes calculating quantities easy. Now let’s look at how to determine the coverage size of an individual shingle.

## Coverage Per Shingle

While a bundle covers 33 square feet, shingle dimensions determine the coverage size for a single shingle. Some common sizes include:

• 3 tab shingles – 5 inches x 36 inches = 5 square feet
• Architectural shingles – 12 inches x 36 inches = 12 square feet

Check manufacturer specifications for exact sizing, as dimensions can vary. When estimating coverage per shingle, be sure to account for the exposed area once installed, not just total size. The exposure will be less than the full shingle dimension.

Knowing both bundle and per shingle coverage gives you all the pieces to calculate total quantities. Next, we’ll walk through the full calculation formula step-by-step.

## The Shingle Quantity Calculation

Using the measurements we’ve gathered, the formula to find your total number of shingle bundles is: Total square footage of roof / Coverage per shingle = Total shingles needed Then: Total shingles needed / 33 sq ft per bundle = Total bundles needed

Let’s do an example calculation for a simple roof:

• Total roof square footage: 1200 sq ft
• Shingle coverage per shingle: 5 sq ft

1200 sq ft / 5 sq ft per shingle = 240 shingles needed

240 shingles / 33 sq ft per bundle = 8 bundles

For a 1200 square foot roof using standard 5 inch shingles, you would need 8 bundles. Repeat this calculation for each roof section, then add for the total bundles required.

When purchasing shingles, it’s recommended to add a 10-20% waste factor allowance. This accounts for:

• Errors in cutting shingles
• Damage during transport or installation
• Mismeasurements or complex roof features

Build in some wiggle room in your order to avoid running out of shingles mid-project. For our example above, adding 15% would mean ordering 9 bundles instead of 8.

Waste can be minimized by careful installation and planning. But it’s wise to overestimate slightly than underestimate your shingle needs.

## Ordering the Precise Amount

With the total number of bundles calculated, round up to the nearest whole number to determine your final shingle order. Buying materials in full bundle increments avoids waste and unnecessary expense. Our example would require 9 bundles of shingles.

Ordering the precise number avoids both shortages and overstock. Too few shingles causes delays and incomplete projects. Too many leads to money wasted on unused materials. Do the measuring twice for accuracy!

There are cost implications to ordering incorrectly. Each extra unnecessary bundle could cost \$50 or more. But a return trip to buy forgotten shingles also carries time and money costs. The right order saves significantly.

Before finalizing any roofing purchase, it’s wise to validate your calculations. Check that your measurements are accurate and exactly match architectural drawings or satellite images. Confirm shingle dimensions and bundle coverage numbers with manufacturer specs. And calculate multiple times to catch any math errors.

Having a partner verify your work is also recommended for a second set of eyes. Use a roofing calculator tool as another check if needed. The time spent confirming will pay off in peace of mind and the right shingle order.

## Recap and Conclusion

We’ve covered a lot of ground on calculating your ideal shingle order. Here are some key takeaways:

• A square equals 100 square feet of roof area.
• Bundle coverage is 33 square feet for most shingle types.
• Precisely measure all roof sections to get total square footage.
• Divide square footage by shingle coverage for total needed.
• Add a 10-20% waste factor allowance.
• Round up to nearest whole bundle increment.
• Validate all measurements and calculations.

With some diligent measuring and number crunching, you can determine the perfect shingle quantity for your specific roofing project. No more guessing games or ordering blindly. You’ll gain confidence buying materials knowing your calculations are accurate.

For further help, don’t hesitate to consult a roofing specialist. They can also assist with measurements or provide a professional opinion on your shingle needs. Investing the effort in precision now saves headaches and hassle down the road.

So next time you’re staring puzzled at those bundles of shingles, remember this guide. Apply the techniques outlined here and you can easily calculate the exact number needed. Get your project started on the right footing with a properly measured shingle order! Your roof will thank you.

### The impact of weather conditions on shingle durability and lifespan

The climate and weather in your area can significantly impact the lifespan of your shingles. Here are some weather factors to consider:

• Heavy rain and snow can accelerate wear and tear on shingles over time. The excess weight and moisture causes damage.
• Strong winds can lift and crack shingles, exposing the roof deck below. This leads to leaks.
• Extreme heat causes shingles to become dried out, brittle and more susceptible to blowing off.
• Freeze and thaw cycles strain shingles as they expand and contract. Cracking occurs.

To account for potential weathering effects, it’s smart to order 5-10% extra shingles if you live in an area with harsh storms, heavy snow, or wide temperature swings. This provides extras for future repairs and replacement shingles over your roof’s lifetime.

Discuss with your roofer the best shingle type for durability in your region’s climate. For example, impact-resistant shingles may be recommended for hurricane-prone areas. Proper installation is also key to weatherproofing.

### The importance of proper installation techniques

Installing shingles correctly ensures they shed water effectively and resist wind, rain, and other elements. Here are some best practices:

• No gaps – Shingles should be laid flush with no spaces in between.
• Proper nailing – Nails must be driven flush to avoid water seeping underneath.
• Aligned rows – Each shingle row should align precisely with those above and below.
• Seal down shingles – Press along edges for a tight seal to the shingle below.
• Follow manufacturer instructions – Comply with all specs for your shingle type.

Taking care with proper installation techniques guarantees your roofing materials last as long as intended. Don’t cut corners – poor installation can significantly reduce shingle lifespan and lead to early leaks or failures. Do it right the first time.

### The role of roof ventilation in shingle longevity

Proper airflow under your roof is vital to shingle health and durability. Moisture that becomes trapped can lead to some major problems:

• Rot and decay of roof decking and framing
• Mold and mildew growth
• Premature deterioration and curling of shingles
• Reduced insulation value from wet underlayment

Ensuring adequate ventilation with soffit vents, roof vents and fans prevents damaging moisture buildup. If your attic is poorly ventilated, investing in additional vents or fans is wise to maintain air circulation.

Talk to your roofer if you are concerned about proper ventilation. They can evaluate your home’s systems and make recommendations for optimal airflow. This small investment preserves your shingles and roof structure.

While beautiful, trees too close to your home can cause extra roof maintenance. Here’s how trees impact shingles:

• Falling leaves and debris clog gutters, causing ice damming and water backup.
• Accumulated debris accelerates wear of shingles as it gets walked on.
• Tree branches abrade and scratch shingles as they blow in the wind.
• Excess shade prevents shingles from properly sealing and drying out.

Regular roof cleaning and gutter maintenance is recommended if nearby trees are an issue. Prune back any overhanging branches touching the roof. And budget for occasional spot repairs where tree damage occurs.

Consider removal for any trees posing a major threat. Avoid planting new trees close to the home. With extra diligence, your shingles can still provide long lasting protection, even with surrounding trees.