The project is the BHS Animal & Plant Science Remodel, a renovation of the existing agricultural science classrooms and support spaces located in Bentonville, Arkansas, based on the architectural and structural drawing package.

This is a single-story interior remodel with minor exterior site improvements, including slab infill, trench slab replacement, and a new sidewalk at a relocated exterior door.

Relevant plan sheets for concrete scope:

• A2.0 – Demolition Plan, demolition notes, slab infill detail
• A2.1 – Floor plan, enlarged sidewalk plan
• A2.2 – Sidewalk details
• S1.0 – Concrete general notes
• S3.1 – Framing plan with slab demo/pourback locations

Concrete scope relevance includes:

1. Interior slab demolition and replacement for sanitary/plumbing modifications
2. New slab infill at removed playground wall areas
3. Exterior sidewalk installation at new exterior door
4. Concrete doweling, reinforcing mesh, expansion joints, vapor barrier, and subgrade prep
5. Patch and repair work at existing slab penetrations

Because this is a remodel project, the concrete package is primarily selective demolition, patch-back work, and small placement quantities, requiring accurate review of slab repair notes and architectural details.

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2. TRADE ABSTRACT / SCOPE OVERVIEW

The complete concrete subcontract scope based on the plans includes:

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A. Demolition

• Sawcut existing slab for sanitary demolition
• Remove slab sections for plumbing trenching
• Remove sidewalk section at new exterior door
• Demo playground wall concrete interfaces
• Remove bollard grout fill flush to slab

Referenced at:

• A2.0 Demolition Notes 8 & 19
• S3.1 slab demo and pourback note

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B. Cast-in-Place Concrete

• New 4″ slab infill
• New 4″ sidewalk
• Concrete repair over plumbing trenches
• Grout fill at bollard voids

Referenced at:

• A2.0 Detail D9
• A2.2 Sidewalk Detail A3

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C. Reinforcement

• Welded wire fabric in slab infill and sidewalk
• #4 dowels into existing slab
• Expansion joints at sidewalk interface

Referenced at:

• S1.0 Concrete Notes
• A2.0 D9
• A2.2 A3

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D. Accessories

• Vapor barrier
• Bentonite strip
• Joint sealant
• Expansion filler
• Chair supports
• Subbase restoration

Referenced at:

• A2.0 D9
• A2.2 A3

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E. Labor / Equipment

• Saw cutting
• Demo hammering
• Formwork
• Placement and finishing
• Small equipment mobilization

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3. PLAN REVIEW PROCESS

For concrete estimating on remodel work, the estimator should review the drawings in this sequence:

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Step 1 – Review Demolition Notes (A2.0)

The first priority is to locate all concrete demolition requirements:

• Note 8: Saw cut/remove slabs as required
• Note 19: Cap plumbing below slab and patch
• Detail D9: Slab infill requirements

These define demolition limits and slab replacement standards.

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Step 2 – Review Floor Plans (A2.1)

Locate where slab work occurs:

• Interior plumbing rework zones
• New sidewalk at door
• Exterior infill areas

These sheets provide dimensions and location references.

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Step 3 – Review Structural Notes (S1.0)

Confirm:

• Concrete strength = 3500 PSI
• WWF installation
• Doweling epoxy requirements
• Slump requirements

This establishes production and material assumptions.

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Step 4 – Review Structural Plan (S3.1)

This identifies slab demo zones:

• “Slab demo and pourback as required to remove and cap sanitary sewer lines”

This determines patch-back quantities.

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4. ESTIMATION PREPARATION STEPS

Before takeoff, the estimator defines:

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Assumptions

• Interior slab assumed 4″ thick
• Sidewalk 4″ thick
• Plumbing trench patch assumed 2′ average width
• Subgrade reusable unless disturbed

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Waste Factors

• Concrete: 10%
• WWF: 8%
• Dowels: 5%

Small placements require higher waste due to minimum delivery charges.

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Labor Assumptions

Because quantities are small, labor productivity is reduced:

• Sawcut/demo: 12 LF/hr
• Slab patch: 0.35 CY/hr
• Sidewalk place/finish: 0.75 CY/hr

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Constructability

Small quantity repairs are labor-intensive because:

• Mobilization is disproportionate
• Multiple isolated placements
• Hand finishing required
• Tight remodel access

These factors significantly increase unit cost.

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5. DETAILED MATERIAL TAKEOFF

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A. Interior Slab Replacement at Plumbing Demo

From S3.1 and plumbing coordination:

Assume 3 trench areas × 20 LF × 2′ wide

Area:

3 × 20 × 2 = 120 SF

Volume:

120 × 4″/12 = 40 CF = 1.48 CY

Waste @10%:
1.48 × 1.10 = 1.63 CY

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Reinforcing Mesh:

120 SF × 1.08 = 130 SF WWF

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Dowels:

40 LF perimeter / 1.5′ spacing = 27 EA

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B. Exterior Slab Infill

Approximate infill area:
15′ × 4′ = 60 SF

Volume:
60 × 4″/12 = 20 CF = 0.74 CY

Waste:
0.74 × 1.10 = 0.81 CY

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C. New Exterior Sidewalk

From A2.1 Enlarged Sidewalk Plan
Dimensions:
4′-4″ × 2′-0″

Area:
4.33 × 2 = 8.66 SF

Volume:
8.66 × 4″/12 = 2.89 CF = 0.11 CY

Waste:
0.11 × 1.10 = 0.12 CY

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Total Concrete Quantity

1.63 + 0.81 + 0.12 = 2.56 CY

Round to 3 CY

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6. LABOR & PRICING BUILD-UP (Prevailing Wage)

Assuming Arkansas public wage rates:

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Material Pricing

Concrete:

3 CY × $250 = $750

WWF:

138 SF × $2.25 = $311

Dowels / epoxy / accessories:

Allowance = $425

Forms / joints / vapor barrier:

Allowance = $300

Material Total:

$1,786

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Labor Pricing

Demo crew:

16 hrs × $72/hr = $1,152

Concrete crew:

24 hrs × $72/hr = $1,728

Labor Total:

$2,880

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Equipment

• Saws, demo hammers, mixer, small tools
  = $650

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Subtotal Direct Cost

$1,786 + $2,880 + $650 = $5,316

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O&P

Overhead 10%:

$532

Profit 10%:

$585

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Final Cost Before Tax:

$6,433

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Tax (Materials @ 8%)

$143

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Final Estimate:

$6,576

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7. FINAL ESTIMATE SUMMARY

Cost Item	Amount
Materials	$1,786
Labor	$2,880
Equipment	$650
Tax	$143
O&P	$1,117
Final Estimate Total	$6,576

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8. ESTIMATOR NOTES / PROFESSIONAL INSIGHTS

The key pricing drivers on this project are mobilization and labor inefficiency, not concrete volume.

Although only ~3 CY of concrete is required, the subcontractor must:

• Mobilize for several isolated placements
• Coordinate with plumbing demolition
• Sawcut and dowel into existing slabs
• Hand finish small repair sections
• Work in occupied remodel conditions

These small patch projects often carry very high unit costs per cubic yard, often exceeding $2,000/CY installed, which is consistent here.

Risk items:

1. Unknown slab thickness
2. Unknown subgrade conditions
3. Plumbing trench width variance
4. Interior access constraints
5. Phased scheduling inefficiencies

Recommended bid clarifications:

• Exclude unsuitable soils
• Exclude rebar beyond indicated dowels/WWF
• Exclude after-hours work
• Include one mobilization only
• Include standard broom finish at sidewalk

These clarifications protect the subcontractor from hidden remodel risk.