Roofing worksheet

1. Roof surface area: 2,262 m²

1. Add the overhang to both ends of the length

   $56+2\times 1$$=58\text{\hspace{0.17em}m}$

2. Add the overhang to both sides of the width

   $34+2\times 1$$=36\text{\hspace{0.17em}m}$

3. Find the flat area the roof covers, seen from above: length times width

   $58\times 36$$=\mathrm{2,088}\text{\hspace{0.17em}m²}$

4. Find the slope factor, how much bigger a 5/12 sloped roof is than its flat area

   $\sqrt{1+{\left(\frac{5}{12}\right)}^2}$$=1.083333$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{2,088}\times 1.083333$$=\mathrm{2,262}\text{\hspace{0.17em}m²}$

6. Turn square meters into square feet, because shingles are sold by the square foot (1 ft² = 0.09290304 m²)

   $\frac{\mathrm{2,262}}{0.09290304}$$=\mathrm{24,347.965363}\text{\hspace{0.17em}ft²}$

7. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{24,347.965363}}{100}$$=243.479654$

8. Add 10% extra for shingles cut off at edges, ridges and valleys

   $243.479654\times 1+0.1$$=267.827619$

9. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $267.827619\times 3$$=803.482857$$=\text{→}$$=804$

2. Roof surface area: 2,058.33 ft²

1. Add the overhang to both ends of the length

   $48+2\times 1$$=50\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $36+2\times 1$$=38\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $50\times 38$$=\mathrm{1,900}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 5/12 sloped roof is than its flat area

   $\sqrt{1+{\left(\frac{5}{12}\right)}^2}$$=1.083333$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,900}\times 1.083333$$=\mathrm{2,058.333333}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{2,058.333333}}{100}$$=20.583333$

7. Add 8% extra for shingles cut off at edges, ridges and valleys

   $20.583333\times 1+0.08$$=22.23$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $22.23\times 3$$=66.69$$=\text{→}$$=67$

3. Roof surface area: 2,372.45 m²

1. Add the overhang to both ends of the length

   $45+2\times 1$$=47\text{\hspace{0.17em}m}$

2. Add the overhang to both sides of the width

   $40+2\times 1$$=42\text{\hspace{0.17em}m}$

3. Find the flat area the roof covers, seen from above: length times width

   $47\times 42$$=\mathrm{1,974}\text{\hspace{0.17em}m²}$

4. Find the slope factor, how much bigger a 8/12 sloped roof is than its flat area

   $\sqrt{1+{\left(\frac{8}{12}\right)}^2}$$=1.20185$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,974}\times 1.20185$$=\mathrm{2,372.452739}\text{\hspace{0.17em}m²}$

6. Turn square meters into square feet, because shingles are sold by the square foot (1 ft² = 0.09290304 m²)

   $\frac{\mathrm{2,372.452739}}{0.09290304}$$=\mathrm{25,536.868753}\text{\hspace{0.17em}ft²}$

7. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{25,536.868753}}{100}$$=255.368688$

8. Add 11% extra for shingles cut off at edges, ridges and valleys

   $255.368688\times 1+0.11$$=283.459243$

9. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $283.459243\times 3$$=850.377729$$=\text{→}$$=851$

4. Roof surface area: 1,861.53 ft²

1. Add the overhang to both ends of the length

   $43+2\times 1$$=45\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $35+2\times 1$$=37\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $45\times 37$$=\mathrm{1,665}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 6/12 sloped roof is than its flat area

   $\sqrt{1+{\left(\frac{6}{12}\right)}^2}$$=1.118034$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,665}\times 1.118034$$=\mathrm{1,861.526591}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{1,861.526591}}{100}$$=18.615266$

7. Add 7% extra for shingles cut off at edges, ridges and valleys

   $18.615266\times 1+0.07$$=19.918335$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $19.918335\times 3$$=59.755004$$=\text{→}$$=60$

5. Roof surface area: 1,371.78 ft²

1. Add the overhang to both ends of the length

   $50+2\times 2$$=54\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $18+2\times 2$$=22\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $54\times 22$$=\mathrm{1,188}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 30° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}30\text{°}}$$=1.154701$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,188}\times 1.154701$$=\mathrm{1,371.78424}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{1,371.78424}}{100}$$=13.717842$

7. Add 7% extra for shingles cut off at edges, ridges and valleys

   $13.717842\times 1+0.07$$=14.678091$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $14.678091\times 3$$=44.034274$$=\text{→}$$=45$

6. Roof surface area: 1,103.39 m²

1. Add the overhang to both ends of the length

   $40+2\times 1$$=42\text{\hspace{0.17em}m}$

2. Add the overhang to both sides of the width

   $22+2\times 1$$=24\text{\hspace{0.17em}m}$

3. Find the flat area the roof covers, seen from above: length times width

   $42\times 24$$=\mathrm{1,008}\text{\hspace{0.17em}m²}$

4. Find the slope factor, how much bigger a 24° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}24\text{°}}$$=1.094636$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,008}\times 1.094636$$=\mathrm{1,103.393369}\text{\hspace{0.17em}m²}$

6. Turn square meters into square feet, because shingles are sold by the square foot (1 ft² = 0.09290304 m²)

   $\frac{\mathrm{1,103.393369}}{0.09290304}$$=\mathrm{11,876.827375}\text{\hspace{0.17em}ft²}$

7. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{11,876.827375}}{100}$$=118.768274$

8. Add 9% extra for shingles cut off at edges, ridges and valleys

   $118.768274\times 1+0.09$$=129.457418$

9. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $129.457418\times 3$$=388.372255$$=\text{→}$$=389$

7. Roof surface area: 1,593.28 ft²

1. Add the overhang to both ends of the length

   $42+2\times 2$$=46\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $28+2\times 2$$=32\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $46\times 32$$=\mathrm{1,472}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 22.5° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}22.5\text{°}}$$=1.082392$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,472}\times 1.082392$$=\mathrm{1,593.281319}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{1,593.281319}}{100}$$=15.932813$

7. Add 11% extra for shingles cut off at edges, ridges and valleys

   $15.932813\times 1+0.11$$=17.685423$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $17.685423\times 3$$=53.056268$$=\text{→}$$=54$

8. Roof surface area: 1,472.63 ft²

1. Add the overhang to both ends of the length

   $44+2\times 1$$=46\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $25+2\times 1$$=27\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $46\times 27$$=\mathrm{1,242}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 32.5° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}32.5\text{°}}$$=1.185689$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,242}\times 1.185689$$=\mathrm{1,472.625797}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{1,472.625797}}{100}$$=14.726258$

7. Add 10% extra for shingles cut off at edges, ridges and valleys

   $14.726258\times 1+0.1$$=16.198884$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $16.198884\times 3$$=48.596651$$=\text{→}$$=49$

9. Roof surface area: 1,228.6 ft²

1. Add the overhang to both ends of the length

   $36+2\times 1$$=38\text{\hspace{0.17em}ft}$

2. Add the overhang to both sides of the width

   $26+2\times 1$$=28\text{\hspace{0.17em}ft}$

3. Find the flat area the roof covers, seen from above: length times width

   $38\times 28$$=\mathrm{1,064}\text{\hspace{0.17em}ft²}$

4. Find the slope factor, how much bigger a 30° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}30\text{°}}$$=1.154701$

5. Multiply the flat area by the slope factor to get the real roof surface

   $\mathrm{1,064}\times 1.154701$$=\mathrm{1,228.601373}\text{\hspace{0.17em}ft²}$

6. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{1,228.601373}}{100}$$=12.286014$

7. Add 13% extra for shingles cut off at edges, ridges and valleys

   $12.286014\times 1+0.13$$=13.883196$

8. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $13.883196\times 3$$=41.649587$$=\text{→}$$=42$

10. Roof surface area: 980.79 m²

1. Add the overhang to both ends of the length

   $28+2\times 2$$=32\text{\hspace{0.17em}m}$

2. Add the overhang to both sides of the width

   $24+2\times 2$$=28\text{\hspace{0.17em}m}$

3. Find the flat area the roof covers, seen from above: length times width

   $32\times 28$$=896\text{\hspace{0.17em}m²}$

4. Find the slope factor, how much bigger a 24° sloped roof is than its flat area. It is 1 ÷ the cosine of the angle

   $\frac{1}{\text{cos}24\text{°}}$$=1.094636$

5. Multiply the flat area by the slope factor to get the real roof surface

   $896\times 1.094636$$=980.794106\text{\hspace{0.17em}m²}$

6. Turn square meters into square feet, because shingles are sold by the square foot (1 ft² = 0.09290304 m²)

   $\frac{980.794106}{0.09290304}$$=\mathrm{10,557.179889}\text{\hspace{0.17em}ft²}$

7. Divide by 100 to get roofing squares, since one square covers 100 ft²

   $\frac{\mathrm{10,557.179889}}{100}$$=105.571799$

8. Add 11% extra for shingles cut off at edges, ridges and valleys

   $105.571799\times 1+0.11$$=117.184697$

9. Multiply by 3 bundles per square, and round up because you can only buy whole bundles

   $117.184697\times 3$$=351.55409$$=\text{→}$$=352$