Insulation worksheet

1. Thickness to add: 7.5 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $52-22$$=30$

2. Divide that by the R each inch gives (4 for expanded polystyrene board (eps)) to get the thickness to add

   $\frac{30}{4}$$=7.5\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $\mathrm{1,000}\times 7.5$$=\mathrm{7,500}\text{\hspace{0.17em}board ft}$$=625\text{\hspace{0.17em}ft³}$

4. Add 9% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{\mathrm{1,000}\times 1.09}{26}$$=41.9231$$=\text{rounded up:}42$

2. Thickness to add: 7.58 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $45-20$$=25$

2. Divide that by the R each inch gives (3.3 for mineral wool batts) to get the thickness to add

   $\frac{25}{3.3}$$=7.5758\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $900\times 7.5758$$=\mathrm{6,818.18}\text{\hspace{0.17em}board ft}$$=568.18\text{\hspace{0.17em}ft³}$

4. Add 8% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{900\times 1.08}{40}$$=24.3$$=\text{rounded up:}25$

3. Thickness to add: 7.88 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $50-24$$=26$

2. Divide that by the R each inch gives (3.3 for mineral wool batts) to get the thickness to add

   $\frac{26}{3.3}$$=7.8788\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $\mathrm{1,000}\times 7.8788$$=\mathrm{7,878.79}\text{\hspace{0.17em}board ft}$$=656.57\text{\hspace{0.17em}ft³}$

4. Add 15% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{\mathrm{1,000}\times 1.15}{50}$$=23$$=\text{rounded up:}23$

4. Thickness to add: 10 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $55-23$$=32$

2. Divide that by the R each inch gives (3.2 for fiberglass batts) to get the thickness to add

   $\frac{32}{3.2}$$=10\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $\mathrm{1,200}\times 10$$=\mathrm{12,000}\text{\hspace{0.17em}board ft}$$=\mathrm{1,000}\text{\hspace{0.17em}ft³}$

4. Add 11% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{\mathrm{1,200}\times 1.11}{28}$$=47.5714$$=\text{rounded up:}48$

5. Thickness to add: 4.83 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $45-16$$=29$

2. Divide that by the R each inch gives (6 for polyisocyanurate board) to get the thickness to add

   $\frac{29}{6}$$=4.8333\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $950\times 4.8333$$=\mathrm{4,591.67}\text{\hspace{0.17em}board ft}$$=382.64\text{\hspace{0.17em}ft³}$

4. Add 9% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{950\times 1.09}{30}$$=34.5167$$=\text{rounded up:}35$

6. Thickness to add: 1.2 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $28-22$$=6$

2. Divide that by the R each inch gives (5 for extruded polystyrene board (xps)) to get the thickness to add

   $\frac{6}{5}$$=1.2\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $\mathrm{1,300}\times 1.2$$=\mathrm{1,560}\text{\hspace{0.17em}board ft}$$=130\text{\hspace{0.17em}ft³}$

4. Add 7% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{\mathrm{1,300}\times 1.07}{40}$$=34.775$$=\text{rounded up:}35$

7. Thickness to add: 7.23 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $62-15$$=47$

2. Divide that by the R each inch gives (6.5 for closed-cell spray foam) to get the thickness to add

   $\frac{47}{6.5}$$=7.2308\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $\mathrm{1,000}\times 7.2308$$=\mathrm{7,230.77}\text{\hspace{0.17em}board ft}$$=602.56\text{\hspace{0.17em}ft³}$

4. Add 8% for waste, then divide the board feet by what one kit covers. Round up, since you can't buy part of a kit

   $\frac{\mathrm{7,230.77}\times 1.08}{42}$$=185.9341$$=\text{rounded up:}186$

8. Thickness to add: 12.8 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $52-20$$=32$

2. Divide that by the R each inch gives (2.5 for blown (loose-fill) fiberglass) to get the thickness to add

   $\frac{32}{2.5}$$=12.8\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $900\times 12.8$$=\mathrm{11,520}\text{\hspace{0.17em}board ft}$$=960\text{\hspace{0.17em}ft³}$

4. Add 8% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{900\times 1.08}{28}$$=34.7143$$=\text{rounded up:}35$

9. Thickness to add: 11 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $60-16$$=44$

2. Divide that by the R each inch gives (4 for expanded polystyrene board (eps)) to get the thickness to add

   $\frac{44}{4}$$=11\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $940\times 11$$=\mathrm{10,340}\text{\hspace{0.17em}board ft}$$=861.67\text{\hspace{0.17em}ft³}$

4. Add 10% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{940\times 1.1}{36}$$=28.7222$$=\text{rounded up:}29$

10. Thickness to add: 6.97 in

1. R-values stack, so subtract what you have from the target to see how much R to add (never below zero)

   $45-22$$=23$

2. Divide that by the R each inch gives (3.3 for mineral wool batts) to get the thickness to add

   $\frac{23}{3.3}$$=6.9697\text{\hspace{0.17em}in}$

3. Multiply the area by the thickness for the volume in board feet (1 ft² one inch thick). Divide by 12 for cubic feet

   $900\times 6.9697$$=\mathrm{6,272.73}\text{\hspace{0.17em}board ft}$$=522.73\text{\hspace{0.17em}ft³}$

4. Add 9% for waste, then divide the area by what one package covers. Round up, since you can't buy part of a package

   $\frac{900\times 1.09}{36}$$=27.25$$=\text{rounded up:}28$