How Many Squares are in a Bundle of Shingles?

If you're embarking on a roofing project, one of the first things you'll need to figure out is how to calculate the number of shingle bundles required. With different types of shingles on the market and variables like roof pitch and regional climate to consider, it can get confusing. To shed some light, we'll walk through what a roofing "square" means, how many bundles typically cover a square for different shingle types, and important considerations for your roofing material order like wastage and extra components.

Whether you're a homeowner trying to estimate needs, a contractor preparing a detailed quote, or a roofer ready to place an order, read on as we unpack everything you need to know about squares and shingle bundles for your roof. With the right information in hand, you can determine how many bundles of shingles you'll require with more confidence.

Defining the Roofing Square Unit

In the roofing industry, a "square" is the common unit of measurement used to calculate the area to be covered. Don't let the name trip you up--a roofing square isn't the same as a square shape. Instead, one roofing square equals 100 square feet of roof area.

The concept of the roofing square dates back over a century and allows for easy quantification of materials. Because most shingle dimensions can be translated into how much area they cover, roofers can calculate squares then place orders accordingly. Understanding what a square represents is the foundation for determining how many shingle bundles you need.

Calculating Total Squares on Your Roof

To determine total roofing squares, you'll need to calculate the square footage of each roof plane. Methods include:

• Physically measuring each slope of your roof with a tape measure
• Using aerial images and online tools to estimate based on roof dimensions
• Inputting roof measurements into a roof square calculator

For simple, single-slope roofs, calculating squares is straightforward. But for complex roofs with multiple angles, valleys, hips and ridges, having an experienced roofer measure is best for accuracy. They can also account for oddities like chimneys and skylights in their measurements.

A Better Visual for Squares

To understand roofing squares, visualize them as a grid overlaying the roof surface, with each "square" representing a 10 foot by 10 foot section, like tiles on a floor. On many roofs each plane will have a fractional number of squares - for example, a 20 foot long by 12 foot wide roof section would equal 2.4 squares (24 feet x 12 feet = 288 square feet).

Shingle Types and Bundles Per Square

Once total roof squares are determined, next comes choosing shingles and calculating materials. The number of shingle bundles needed per square depends on the type of shingle specified:

3-Tab Asphalt Shingles

• Weigh around 235 pounds per square
• 3 bundles typically cover 1 square

Laminated Asphalt Shingles

• Heavier type, 385-430 pounds per square
• 4-5 bundles often needed per square

Premium Laminates and Specialty Shingles

• Heaviest options due to material thickness and durability
• May need up to 6 bundles per square

These per-square guidelines help calculate needs for the main roof covering, but starter strips and caps along hips, ridges, and rakes also need quantification:

Starter Shingles

• Placed along eaves before main shingles
• Often 3-tab shingles cut into thirds
• Multiply lineal feet of eaves by 0.667 to get squares

Hip and Ridge Caps

• Capped along angle seams on hips and ridge lines
• Match or complement main shingle type
• Need 1 linear foot of cap per 1 lineal foot of hip or ridge

Factoring in Wastage

One important consideration when ordering shingles is accounting for waste. During installation, shingles must be cut to fit valleys, around vents, and along rakes and edges. Breakage can also occur when transporting bundles across the roof. Industry standards recommend adding at least 5% extra as waste when calculating bid or purchase amounts. For intricate roofs, waste can reach up to 15%.

To incorporate wastage into square calculations:

1. Total all squares needed for shingle courses, ridges, hips, and starter shingles
2. Multiply squares total by waste percentage (5-15% usually)
3. Add waste square amount onto total from Step 1

Once final squares with waste added are determined, divide by the bundles per square rate based on shingle type chosen. Then round bundle numbers up to simplify ordering. This provides a buffer for extra waste if needed.

Other Factors Impacting Shingle Quantities

While the above provides a general guide on shingle bundle calculations, every roof has unique considerations that can alter totals. Some key factors include:

Roof Slope and Pitch

On steeper sloped roofs over 6/12 pitch, the surface area is greater so more squares of shingles are required . And at higher pitches above 14/12, standard shingles become trickier to install cleanly. This warrants using specialty steep slope shingles, which are thicker and more expensive.

Regional Weather and Climate

In zones with regular high winds, heavy rain or snow, or large temperature swings, enhanced shingles with weather resistance built in should be utilized. However, these often weigh more per square. Budgeting for thicker shingles plus heavier material loads from extra bundles helps offset surprises.

Unique Roof Shapes and Elements

Extreme roof angles, an abundance of valleys and dormers, odd extensions and protrusions can all drive up material requirements due to cutting and fitting challenges.

Performing accurate square and bundle calculations takes diligence, but prevents shortages or over-ordering. To recap key points in planning your roofing project:

• Calculate total squares for each roof plane and feature
• Determine bundles needed per square for shingle type chosen
• Account for 10-15% wastage in your square estimates
• Factor in any steep slope, climate, or shape considerations
• Order starter strips, and hip and ridge caps in needed lengths

While the math may seem intensive, getting shingle quantities and budget accurate makes for smooth installation and cost management. For DIYers new to estimating, don't hesitate to consult roofing specialists. An expert can survey your specific roof and define needs. Taking the time upfront prevents headaches both on the roof and financially!