Estimating the Cost for the

Concrete Pad

O’Keefe - LBHS

Concrete Estimating

• Common Uses of Concrete

• Reinforcing Bar

• How Much Will the Concrete Cost?

• Estimating the Cost of a Pad

• Cost Estimate

• Cost Estimator

Common Uses of Concrete

• Foundations and footings

• Driveways and sidewalks

• Floors

• Retaining walls

• Piers

• Columns

Reinforcing Bar

Concrete has high compression strength, yet poor

tensile strength. Rebar is added to increase the

tensile strength.

Reinforcing Bar

Rebar is also used to pin one structural element to

an adjacent element.

How Much Will the Concrete Cost?

Concrete is sold by volume and measured in cubic

yards (yd3).

Estimating the Cost of a Pad

Pad size = 16 ft x 18 ft floor

4 in. thick

• Convert all units to ft

16 ft, 18 ft, .333 ft

• Calculate volume (L x W x t)

• Convert ft3 to yd3

ft ft . ft ft 316 18 333 96

3 3(27 ft 1 yd )

yd

ft . yd say 4.0 cu. yd ft

33 3

3

196 3 55

27

Estimating the Cost of a Pad

Concrete is typically sold in increments of ½ yd3

$98/ yard3 x 4.0 yards3 = $392

Estimating the Cost of the Pad

Rebar

• Placed every two feet

(max.) on a grid

• Sold in 10 ft lengths

• Must be lapped 6 in. to

maintain strength

• Maintain a 3 in. edge

distance

6 in. lap

3 in

. e

dg

e d

ist.

Estimating the Cost of the Pad

Rebar

(19) 10 ft bars

How many 10 ft pieces of

rebar are needed?

(9) 8 ft bars

(10) 6 ft bars

38

3 in. edge d

ist.

6 in. lap

Estimating the Cost of the Pad

Rebar

• Each piece of #4 rebar

costs $4.78.

38 x $4.78 = $181.64

Concrete $392.00

Rebar +$181.64

Total $573.64

Other associated costs

include material for forms,

gravel, and labor.

Cost Estimate

• A forecast of the cost of a future project

• Prepared at different levels of a project

– Conceptual Design

– Construction Documents

– Bid Phase

• Includes

– Quantity take-off − Subcontractor quotes

– Material costs − Indirect costs

– Labor rates and costs − Profit margin

– Equipment costs

• Completed with cost estimating software

Cost Estimator

• Specialize in developing cost information for

building projects

• Most employed in construction industry

• Most have gained experience through working in

building construction industry

• Employed by

– Owner

– Project manager

– Construction Contractor

– Design professional

• May be discipline specific (electrical, structural, etc.)

Concrete Estimating

• Common Uses of Concrete

• Reinforcing Bar

• How Much Will the Concrete Cost?

• Estimating the Cost of a Pad

• Cost Estimate

• Cost Estimator

Image Resources

Microsoft, Inc. (n.d.). Clip art. Retrieved March 18, 2009, from

http://office.microsoft.com/en-us/clipart/default.aspx