Sinking in Concrete

Day 4 – Firepit and Curbs

What Information?

• After you talked to Mr. Johansen, you discovered that he would like a 2’ border surrounding his firepit.

• Mrs. Johansen would only like the garden border around the new edges and not around the natural walls. She would like them to be 4” high and 6” wide. To do this you will need the curb to extend 2” below the ground.

Materials

• For the Firepit, you will need gravel, concrete, rebar and plywood.

• For the curbs you will need ready mix concrete and plywood.

Fire Pit

• The Fire pit will be found similar to sidewalk #1. We will need to find the area of the big circle and subtract the area of the small circle.

2’

2’

• Abig-Asmall

• The area will be 25.13 square feet• Remember this is the amount of rebar needed.• Add it to the chart

squarefeetA

A

A

rrA

13.25

14.327.28

)1()3( 22

22

Gravel Concrete Rebar Wood

Fire Pit 25.13 square feet

Gravel

• V= Abase * Height• V= 25.13 * 0.5• V=12.57 cubic feet

Gravel Concrete Rebar Wood

Fire Pit 12.57 cubic feet

25.13 square feet

Concrete

• V= Abase * Height• V= 25.13 * 0.42• V=10.55 cubic feet

Gravel Concrete Rebar Wood

Fire Pit 12.57 cubic feet

10.55 cubic feet

25.13 square feet

Plywood

• We will need the circumfrence of both circles for the plywood measure.

• First do the big ring

• Then the small

• Now add them together! 6.28 +18.85=25.13’

'28.6

)1(2

2

C

C

rC

'85.18

)3(2

2

C

C

rC

Gravel Concrete Rebar Wood

Fire Pit 12.57 cubic feet

10.55 cubic feet

25.13 square feet

25.13’

Plywood Cost

• Remember there are 8’ in one strip

• 25.13/8 = 3.14

• That is less than one sheet since you can get 8 in one sheet!

• 3.14/8 = .39 of a sheet

• We will order 1 sheet

Rebar Cost

• Recall there are 32 square feet in one sheet of rebar.

• We need 25.13

• 25.13/32 = .79

• We will order 1 sheet

Gravel Cost

• Convert your units!

• 12.57 * 0.037 = 0.47 cubic yards

• We will order 1 cubic yard

cuyd

x

cuft 037.1

57.12

Concrete Cost

• Convert to cubic yards first, then to cubic meters.

• 10.55 * 0.037 = 0.39

• 0.39 * 1.82 = .71 cubic meters

cuyd

x

cuft 037.1

55.10

cumt

x

cuyd 82.11

039.0

Gravel Concrete Rebar Plywood

How is it sold?

Cubic Yard

Cubic meter

4x8 sheet

4x8 sheet

How much does each unit cost?

$7.00 $200 $14.45 $37.00

How many units do we need?

1 1 1 1

Total of each item: (row 2 times row 3)

7.00 200.00 $14.45 $37.00

Total Cost

• Grave (A-grade): $7.00

• Concrete: $200.00

• Rebar: $14.45

• Wood: $37.00

• Total: $258.45

+ tax (multiply by 1.13) = $292.05

Curb #1(Rose Garden)

The curb for the rose garden will be beside sidewalk one that was calculated on day 2 with the plywood.

• Small Circle:C=2*3.14*18113.04 ** don’t forget to divide by 4113.04/4 = 28.26’• Remember that 6” = .5’• Remember that 4” + 2” = 6”

• V=l*w*h

V=28.26 * .5 * .5

V=7.07 cubic feet

Plywood

• We will need to frame all four sides • P= l+l+l=l• To find the missing inside curb length. Use the

circumference fomula again and divide by 4.• The radius is the 18’ - .5’ for the curb.C=2*3.14*17106.81 ** don’t forget to divide by 4106.81/4 = 26.7’• P= 28.26+.5+26.7+.5 = 55.96’

Ready Mix

Concrete

Wood

Curb #1 7.07 cubic feet

55.96’

•You try curb #2

Curb #2(Flower Bed by Bedroom #3)

• This is a rectangular flower bed shaped like an L

• We will need 3 edges as 3 are natural walls with the house.

Measurements

• The front side is 2’

• The front edge is 11+2 = 13’

• The side edge is 12 +2 (closet) +2 (garden) = 16’

• 2+13+16 = 31’

Calculate

• V=l*w*h

V=31*.5*.5

V=7.75 cubic feet

• Inside edge is .5’ less along the house, 1’less along the front and .5’less on the side.

• 31-1-.5-.5 = 29

P = 31+29 +.5+.5= 61’

Ready Mix

Concrete

Wood

Curb #1

Curb #2

Total

7.07 cubic feet

7.75 cubic feet

14.82 cubic feet

55.96’

61’

116.96’

Plywood Cost

• 116.96’/8’ =14.62

• 14.62/8 strips = 1.83 sheets

• We can not order .83 sheets so we will order 2

Concrete Cost

• It takes 2.3 bags of ready mix to fill 1 cubic foot.

• We have 14.82 cubic feet.

• 14.82 * 2.3 = 34.09

• We will need to order 35 bags

Ready Mix Wood

How sold 60lb bag 4x8 sheet

Price per unit $5.99 $37.00

How much needed

35 2

Cost $209.65 $74.00

Total of the sidewalks

$283.65

What is the total price?

• Now lets add our prices from all three days!– Driveway - $ 3685.78– Sidewalks - $ 3647.36– Deck piers - $ 261.74– Fire pit - $ 292.05– Curbs - $ 283.65TOTAL: $8170.58(without wear and tear and labour)

What if we total at the end instead of by the job?

Materials Checklist

 Gravel(cubic yard)

Rebar(cubic yard)

Concrete(cubic meter)

Wood8x4

Tubes10” x 8’ Brackets

Ready Mix60lb bag

Driveway B- 17.69A- 8.85 14.94   13.52 1.5       

Sidewalks A - 8.82  14.9   13.49  3.91      

Curbs        1.2     34.09 

Deck piers          3  6  30

Fire pit A - .47  .79  .71  1.83      

Total Amounts

B-grade

A-grade

Concrete Plywood Ready Mix

Tubes Rebar Post Holders

Total Needed

17.69 18.14 27.72 8.44 64.09 3 30.63 6

Order Quantitiy

18 19 28 9 65 3 31 6

Let’s price the whole job (without wear and tear and labour)• Gravel B-grade: 18 * $6.00= $108.00• Gravel A-grade: 19 * $7.00= $133.00• Concrete: 28 * $200.00= $5600.00• Wood: 9 * $37.00= $333.00• Rebar: 31 * $14.45= $447.95• Tubes: 3 * $11.37= $34.11• Brackets: 6 * $2.97= $17.82• Ready Mix: 65 * $5.99= $389.35• Total: $7063.23

• Now add the tax!

• $7063.23 * 1.13 = $7981.45

• So, if we priced this individually it would cost $8170.58. It is cheaper to price the whole job and there will be less scrap material. It will also allow you to give a more competitive price!