Gresham Concrete Calculator
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💧 Drainage Critical — 49 in. Annual Rain
Gresham OR
Concrete Calculator — Yards, Bags & Cost
Calculate cubic yards, bags, and Gresham OR-accurate ready-mix costs for any Multnomah County project. Includes Oregon’s 18-in. frost depth, wet PNW subgrade drainage guidance, and ORSC 2021 compliance notes.
$162Avg Gresham Ready-Mix (per Cu Yd)
49 in.Annual Rainfall — Drainage Is Critical
3,000Min PSI — ORSC 2021 Residential Flatwork
18 in.Frost Depth — Multnomah County, OR
🚗 Driveway
🏡 Patio / Slab
🏗️ Foundation
🏢 Garage Floor
🚶 Walkway
🏊 Pool Deck
The Gresham OR Concrete Calculator helps homeowners, contractors, and builders in Gresham, Oregon estimate cubic yards, bag count, and ready-mix costs for any Multnomah County project. Gresham pricing runs $153–$172/yd for 3,000–4,000 PSI — Pacific Northwest pricing is higher than the Midwest due to regional labor costs and material demand around the Portland metro. Gresham’s defining concrete challenges are drainage and wet subgrade — the city receives 49+ inches of rain annually, and native soils (Gresham Series — poorly drained silty clay over weathered glacial till) stay saturated much of the year. Never pour concrete on wet, soft, or saturated subgrade — it must be dewatered and properly compacted first. Frost depth is a mild 18 inches (ORSC 2021 / Gresham Building), and no air entrainment is required (mild Pacific oceanic freeze-thaw). All work falls under the Oregon Residential Specialty Code (ORSC 2021) permitted through the City of Gresham Building Division. More tools at Concrete Toolkit.
🌧️ Gresham OR Concrete Calculator
🌧️ Multnomah Co. · ORSC 2021 · 18-in. Frost · Drainage Critical · No Air Entrainment
Gresham OR Concrete Calculator
Cubic yards, bags & Gresham OR / Multnomah County ready-mix cost — instant results
🚗 Driveway
🏡 Patio
🏗️ Foundation
🏢 Garage
🚶 Walkway
Enter dimensions for volume, bags, and Gresham OR / Multnomah County material cost estimate.
Driveway: 4 in. min, 3,000–3,500 PSI per ORSC 2021. Gresham permit required. Dewater subgrade — never pour on wet OR saturated soil. 4–6 in. 3/4-in. crushed rock base. Drain away from structure. No air entrainment needed. Seal every 2–3 yrs.
Walkway 4 in · Driveway 4–5 in · Patio 4 in · Garage 4 in · Foundation 4–6 in · Footing 8–12 in · Retaining Wall 8–12 in
Cubic Yards Required
—
Including waste factor
📋 Project Summary
💵 Gresham OR Cost Estimate
📐 Gresham OR Driveway Cross-Section — ORSC 2021 / PNW Wet Subgrade Drainage Standard
Broom Finish · ORSC 2021 · Drain Away from Structure · Seal Every 2–3 Yrs · No Air Entrainment
Concrete — 4 in. min (ORSC 2021 Residential)
3,000–3,500 PSI · #3/#4 Rebar or Fiber Mesh · 7-Day Cure · No Air Entrainment (PNW F0/F1)
⬛ #3 / #4 Rebar @ 18 in. o.c. or Poly Fiber Mesh — Multnomah County / Gresham OR Standard
💧 6-mil Vapor Barrier — Required Under All Garage & Slab-on-Grade per ORSC 2021
💧 French Drain / Perforated Pipe at Footing Base — Critical in PNW Wet Soils — Daylight to Safe Outfall
🪨 4–6 in. Compacted 3/4-in. Crushed Rock (OR Standard Base) — MUST Be Dry Before Pour
❄️ FROST ZONE — 18 in. Below Grade (Multnomah Co., OR per ORSC 2021 / Gresham Building Dept.)
🟤 Native Gresham Series Silty Clay / Glacial Till — Dewater & Compact to 95% Proctor Before Any Pour
27Cu ft per cubic yard
18 in.Frost depth — Multnomah Co. OR
$162Avg Gresham OR mix / yd
Concrete Slab
Rebar / Fiber Mesh
Vapor Barrier
French Drain
3/4-in. Crushed Rock
18-in. Frost Zone
Gresham OR Concrete — What You Need to Know
Gresham is Multnomah County’s second-largest city — a Portland metro suburb of ~115,000 at the base of the Columbia River Gorge. Its concrete environment is defined by the Pacific Northwest’s relentless wet season: 49+ inches of annual rainfall concentrated from October through April, native Gresham Series soils that are classified as somewhat poorly drained silty clay over weathered glacial till, and a mild but real frost exposure of 18 inches per ORSC 2021 / City of Gresham footing checklist. Unlike Midwest pages, Gresham does not require air-entrained concrete (oceanic Zone 9a climate, only 20–30 frost days/year). The dominant challenges are wet subgrade dewatering, proper drainage installation, and timing pours around the PNW rain calendar.
💧 Wet Subgrade — Gresham’s #1 Concrete Challenge
Gresham’s combination of 49+ inches of annual rainfall and poorly drained native silty clay soils means subgrade is often wet, soft, or saturated for much of the year. Never pour concrete on wet or soft subgrade — water in the base mix compromises concrete strength and causes settlement and cracking. Before any Gresham concrete project: (1) dewater using a submersible pump, French drain, or perforated pipe system; (2) allow the base to dry until it passes the “thumb test” (no depression under firm thumb pressure); (3) compact crushed rock base to 95% Proctor. Budget for a French drain or perimeter drain at footing base — this is not optional in Gresham’s wet PNW soils. Also ensure all flatwork surfaces drain away from structures at 1–2% minimum slope to prevent surface water infiltration.
🔵 Gresham OR / ORSC 2021 Concrete Quick-Reference
All flatwork: 3,000 PSI min (ORSC 2021); 4 in. driveways/patios; no air entrainment required (PNW mild F0/F1) · Footings: 18 in. below grade min (Multnomah Co. frost depth — confirmed by Gresham Building) · Garage / interior slabs: 4 in. min, 6-mil vapor barrier per ORSC · Key PNW prep: Dewater subgrade, install French drain at footing base, use 4–6 in. compacted 3/4-in. crushed rock base · Slope: All exterior flatwork 1–2% away from structures · Control joints: Every 10 ft (10× thickness in feet) · Sealer: Penetrating silane/siloxane every 2–3 years · All OR contractors must hold valid Oregon Construction Contractors Board (CCB) License — verify at Oregon CCB.
📅 Best Pouring Season — May Through September
Gresham’s concrete pouring window is tightly constrained by PNW rain: May through September is ideal — rainfall drops significantly and temperatures stay above 50°F for reliable curing. October–April is possible but requires careful scheduling around rain events, protecting fresh concrete from rain for a minimum of 4–6 hours after finishing (rain can wash cement from fresh concrete surface), and monitoring subgrade drainage. ACI 308 wet-curing methods are naturally assisted by Gresham’s ambient humidity — reduce water evaporation concerns but protect from actual precipitation. Book suppliers and contractors 2–4 weeks ahead for the June–August peak window.
☀️ No Air Entrainment — Mild Pacific Climate
Unlike northern and Midwest cities in this series, Gresham does not require air-entrained concrete. With only 20–30 frost days per year and a shallow 18-in. frost depth (Zone 9a oceanic), ACI 318 classifies Gresham as Exposure Class F0/F1 — negligible to mild freeze-thaw. Standard non-air-entrained 3,000–3,500 PSI concrete is ORSC-compliant for all exterior flatwork. This saves $5–$12/yd versus northern markets. Focus your specification attention on drainage, subgrade dewatering, and proper sloping — not air content or frost protection.
How to Calculate Concrete — Gresham OR
Multiply length × width × (depth ÷ 12) for cubic feet, divide by 27 for cubic yards, add 10% overage. Major Gresham / Portland metro suppliers include CalPortland, CRH (formerly Knife River), CEMEX, Pacific Ready Mix, and regional Multnomah County independents. Short-load fees run $100–$175 for under 3–5 cu yd. Schedule pours for dry weather windows — confirm a 24-hour dry forecast minimum before pouring any exterior flatwork.
📐 Gresham OR Concrete Formula
Volume (cu ft) = Length (ft) × Width (ft) × [Depth (in) ÷ 12]
Volume (cu yd) = Volume (cu ft) ÷ 27
Order Qty = CEIL[ Volume (cu yd) × Waste Factor ]
Example: 20 ft × 20 ft × 4 in = 133.3 cu ft ÷ 27 = 4.94 cu yd → Order 5.5 cu yd (+10%)
⚠️ Wet Subgrade, Drainage & OR CCB License Warning — Gresham OR
Never pour concrete on wet, saturated, or soft subgrade in Gresham — always dewater and compact first. Install drainage at footing base. Always pull a permit — Multnomah County inspectors check subgrade preparation and footing depth. Verify all Oregon contractor licenses at Oregon Construction Contractors Board (CCB). Unpermitted work must be disclosed at sale in Oregon.
Gresham OR Concrete Pricing — Current Reference
Multnomah County / Portland metro ready-mix pricing is above the national average — high Pacific Northwest labor costs, Portland metro demand, and regional material logistics push prices higher than Midwest or Southeast markets. No air-entrainment premium applies, but PNW labor and delivery costs are significant. Year-round suppliers available but peak-season (Jun–Aug) booking is recommended.
| Mix / PSI | Gresham OR Price / Cu Yd | National Avg | Best For | Air Entrained? | ORSC 2021 |
|---|---|---|---|---|---|
| 2,500 PSI — Light | $148–$160 | $130–$148 | Light interior slabs only | Not Needed | Below Flatwork Min |
| 3,000 PSI — OR Standard ✓ | $153–$168 | $143–$158 | Driveways, patios, walkways | Not Needed | Compliant |
| 3,500 PSI — Mid Strength | $160–$175 | $153–$166 | Pool decks, wet subgrade slabs | Not Needed | Compliant |
| 4,000 PSI — Structural | $168–$185 | $161–$173 | Foundations, structural slabs | Not Needed | Compliant |
| 5,000 PSI — Commercial | $182–$200 | $178–$193 | Commercial / engineered | Not Needed | Compliant |
PNW & West Coast Concrete Prices by City
| City | County / State | 3,000 PSI / Cu Yd | Frost Depth | Air Entrained? | Key Challenge |
|---|---|---|---|---|---|
| Gresham | Multnomah, OR | $153–$168 | 18 in. | Not Required | Wet PNW Subgrade |
| Portland | Multnomah, OR | $155–$170 | 18 in. | Not Required | Wet Subgrade |
| Seattle | King, WA | $165–$185 | 12 in. | Not Required | Wet/Clay Subgrade |
| Eugene | Lane, OR | $148–$163 | 12–18 in. | Not Required | Moderate Clay |
| Sacramento | Sacramento, CA | $160–$178 | 0–6 in. | Not Required | Adobe Clay / Heat |
✅ City of Gresham Permit Info
The City of Gresham Building Division requires permits for new driveways, patio slabs, pool decks, foundations, and retaining walls. Apply at greshamoregon.gov/building-permits. Standard permits process in 3–7 business days. Inspectors verify frost depth (18 in.), subgrade preparation, and vapor barriers per ORSC 2021. Verify Oregon contractor licenses at Oregon CCB.
Gresham OR Concrete Tips
- Dewater and dry subgrade before every pour — Gresham’s wet soil is the #1 failure cause — Never place concrete on wet, soft, or saturated ground. Pump out standing water, allow the base to drain, then compact 4–6 in. of 3/4-in. crushed rock to 95% Proctor. The base must pass the “thumb test” — no impression under firm pressure before pouring. Wet subgrade causes settlement, cracking, and structural failure regardless of concrete strength or thickness.
- Install drainage at the footing base — French drain is standard in PNW — All Gresham footings and slab perimeters should include a perforated pipe (French drain) surrounded by drain rock and filter fabric, daylighting to a safe outfall away from the structure. Gresham’s high annual rainfall and poorly drained native soils make hydrostatic pressure a chronic problem. Slope all exterior flatwork 1–2% away from buildings for positive surface drainage.
- Schedule pours for dry weather windows — check 24-hour forecast — Gresham’s October–April rainy season makes outdoor concrete work risky. Schedule pours only when a 24-hour rain-free window is confirmed. Rain hitting fresh concrete within 4–6 hours of placement washes cement off the surface, weakening the paste matrix and causing surface dusting. If caught by unexpected rain, cover with plastic sheeting immediately. Ideal pouring season is May–September — consider this when planning project timelines.
Frequently Asked Questions — Gresham OR
How much does concrete cost per yard in Gresham OR?+
$153–$168 per cubic yard for standard 3,000 PSI ready-mix in Gresham / Multnomah County — above the national average of $143–$158/yd due to Portland metro labor costs, high PNW construction demand, and delivery logistics. No air-entrainment premium unlike Midwest markets. Short-load fees $100–$175 for under 3–5 cu yd. Major suppliers include CalPortland, CRH (Knife River), CEMEX, and Pacific Ready Mix. Get 2–3 quotes and book 2–4 weeks ahead in June–August peak season.
What is the frost depth in Gresham OR?+
The frost depth in Gresham / Multnomah County is 18 inches per the Oregon Residential Specialty Code (ORSC 2021) and confirmed by the City of Gresham’s own Residential Footing and Foundation Inspection Checklist. All exterior footings — foundations, columns, steps, and isolated piers outside conditioned crawl spaces — must extend a minimum of 18 inches below finished grade. This is much shallower than Midwest cities (Grand Rapids 42 in., Green Bay 48 in.) and reflects Gresham’s mild Pacific oceanic climate.
Does Gresham OR require air-entrained concrete?+
No — air entrainment is not required for exterior flatwork in Gresham OR. Gresham’s Pacific oceanic climate (USDA Zone 9a, only 20–30 frost days/year) is classified as ACI 318 Exposure Class F0/F1 — negligible to mild freeze-thaw. Standard non-air-entrained 3,000–3,500 PSI concrete is fully ORSC 2021-compliant for all exterior flatwork. Unlike Grand Rapids MI (6% required) or Green Bay WI (6% required), Gresham concrete does not need air entrainment. Focus on drainage, dewatering, and wet-weather scheduling instead.
Who are the main ready-mix suppliers in Gresham OR?+
Major ready-mix concrete suppliers serving Gresham and the Portland metro east side include CalPortland (largest PNW regional supplier), CRH / Knife River, CEMEX, Pacific Ready Mix, and several Multnomah County regional independents. Most can accommodate 24–48 hour lead times outside peak season. During June–August, book 1–2 weeks ahead. Always specify PSI (3,000 PSI standard), confirm no air entrainment is needed, and check short-load fees for orders under 3–5 cu yd ($100–$175 typical).
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