Smithtown Concrete by the Numbers: Climate, Soil, Code and Cost

Last reviewed 2026-07-25. Journalists, researchers, and community groups are welcome to cite any figure on this page with attribution and a link.

Nearly every claim made about concrete durability on Long Island rests on figures that are published and checkable: what the weather does at the nearest long-run climate station, what the soil survey says about the ground, what the Town code actually requires, and what the concrete industry specifies for a deicer climate. This page collects those numbers with a source for each. Nothing here is estimated or recalled. Where the public record does not answer a question homeowners commonly ask, the last section says so plainly instead of filling the gap with a number that sounds plausible.

One note on the climate station, because it causes confusion. There is no long-run NOAA record at Smithtown itself. The nearest station with a full 1991-2020 normals record is Islip - Long Island MacArthur Airport, listed under station identifier USW00004781, roughly seven miles southeast of Smithtown on the outwash plain. It is the record used throughout this site. Being inland and south of the Sound, it will read slightly differently from the north shore edge of the Town on any given night, but it is the closest published baseline available and it is the one used consistently here rather than switched between stations to suit an argument.

How often does concrete here actually freeze?

The 1991-2020 climate normals for Islip put the annual average temperature at 53.1 degrees, normal annual precipitation at 45.99 inches and normal annual snowfall at 31.8 inches. The figure that matters for concrete durability, though, is the monthly count of days with a minimum temperature at or below 32 degrees. Summed across the year those counts come to about 98 nights. January leads at 24.8, followed by February at 22.3 and December at 20.9, but the month that does the most damage to flatwork is March.

March is the problem because of the spread between its two normals. The normal daily minimum for March at Islip is exactly 32.0 degrees while the normal daily maximum is 47.7, and the station still records 16.9 days a month at or below freezing. That is a surface thawing every afternoon and refreezing every night, roughly seventeen times, at exactly the point in the year when snowmelt and 4.51 inches of normal March precipitation have the concrete at its wettest. Freeze-thaw damage is a function of how saturated the concrete is when it freezes, which is why March rather than January is when scaling and spalling show up.

What does the concrete industry specify for this exposure?

Concrete durability in freezing conditions is governed by exposure class, and the classes are defined by how wet the concrete stays and whether deicing chemicals are present. A Long Island driveway, walkway or apron that gets salted is class F3, the most demanding of the three. The criteria carried in ACI 318 and summarized in the ready-mix industry's research on freeze-thaw resistant mixtures set the requirements for each class, and the difference between them is not marginal - class F1 accepts 3,500 psi and a 0.60 water-cement ratio, while F2 and F3 require 4,500 psi and 0.45.

The same research makes two points worth carrying into any conversation with a contractor. First, it identifies a critical degree of saturation of approximately 88 percent, above which concrete fails under freeze-thaw regardless of how good the air entrainment and water-cement ratio are, and below which it survives. That is a strong argument that drainage is a durability specification. Second, it states that scaling is exacerbated in the presence of deicing salts because they increase water absorption and retention, which is the mechanism behind the flaked wheel tracks on nearly every older driveway in the Town.

Where should the control joints go?

Joint spacing is not a matter of taste and it is published. Industry guidance for slabs on grade sets maximum joint spacing at 24 to 36 times the thickness of the slab, limited to a practical maximum of 15 feet. The joint groove should have a minimum depth of one quarter of the slab thickness and not less than one inch. Conventional saw-cut joints should be run within 4 to 12 hours after the concrete has been finished. And all panels should be square or nearly so, with length not exceeding 1.5 times the width.

Applied to the slab thicknesses used in residential work, that produces the table below. Note where the 15-foot cap starts to govern: at six inches, the 36x figure would allow 18 feet, but the practical maximum overrides it. Note also the panel shape rule, which is the one most often ignored. A driveway 10 feet wide with joints every 20 feet satisfies nobody's spacing rule and produces a transverse crack in the middle of every panel, because the 2:1 aspect ratio guarantees it.

What does the Town of Smithtown code actually require?

The Town code touches concrete work in four separate chapters, and they are easy to confuse. Chapter 112 governs building permits, including the requirement at Section 112-26 that no retaining wall, sea wall or bulkheading be constructed, altered, removed or demolished without a permit, and the exemption at Section 112-10A covering ordinary non-structural repairs and a detached shed of not more than 144 square feet and 12 feet in height in a conforming location. Chapter 245 governs work in Town streets. Chapter 248 sets construction specifications for street improvements. Chapter 322 is the zoning code and sets the limits on where and how much you can pave.

For steps and stoops, the governing document is the Residential Code of New York State rather than Town code. The New York Department of State technical bulletin on residential exit doors, stairs and landings states that riser height shall be not more than 8 1/4 inches, tread depth shall be not less than 9 inches, stairway landings shall be not less than 36 inches deep in the direction of travel, and handrails shall be provided on not less than one side of each continuous flight with four or more risers. Footing depth is a different matter: the Department of State bulletin on Table R301.2 states that the local jurisdiction shall provide the minimum depth of footing below finish grade, so that figure comes from the Smithtown Building Department for your address.

What the ground and the housing stock look like

The soil across the outwash sections of Suffolk County is dominated by the Riverhead series, which the USDA Official Series Description characterizes as very deep and well drained, formed in glacial outwash derived primarily from granitic material, with saturated hydraulic conductivity described as high in the solum and very high in the substratum. The profile is sandy loam or fine sandy loam at the surface over loamy sand, then coarse sand and gravel. The series is mapped on outwash plains, valley trains, beaches and water-sorted moraines. The U.S. Geological Survey's surficial geology mapping shows why the north shore differs: moraines carry till beneath them, unsorted rather than water-sorted, which drains and compacts far less predictably than outwash does.

The demand side is a function of the housing stock. Smithtown recorded 116,296 residents at the 2020 census on 53.75 square miles of land, with an owner-occupied housing rate of 88.7 percent and a median owner-occupied home value of $669,900. The Town's own comprehensive plan update describes it as almost 97 percent developed and notes that most of the Town was built after 1950. Put those together and you get the actual market: long-tenure owner-occupied houses whose original driveways, walks and stoops are now sixty to seventy years old, in a town with essentially no room left to build new. Replacement and repair, not new construction, is the work.

Sources & Methodology

Every figure above was taken from the primary sources below (accessed 2026-07-25). Where a number is derived (arithmetic on published figures) or covers a broader period or area, the text says so.

1. NOAA NCEI - U.S. Climate Normals 1991-2020, Islip LI MacArthur Airport — Monthly 1991-2020 normals for station USW00004781. Source of every temperature, days-below-freezing and snowfall figure on this page, including the 24.8 January count, the 16.9 March count and the 31.8 inch annual snowfall normal. The annual averages of 53.1 degrees and 45.99 inches of precipitation come from the matching annual and seasonal normals dataset for the same station.
2. U.S. Census Bureau QuickFacts - Smithtown town, Suffolk County, New York — Source of the 116,296 population count, the 53.75 square mile land area, the 88.7 percent owner-occupied rate and the $669,900 median owner-occupied home value. The corresponding CDP figures for Commack, Kings Park, St. James and Nesconset come from the QuickFacts pages for each of those places.
3. Town of Smithtown Code, Chapter 245 Streets and Sidewalks, Article IV Excavations — Source of Section 245-15 requiring a permit for excavation in a Town street, the Section 245-18A(2) apron fees of $150 residential and $200 commercial, the Section 245-18A(8) curb cut and sidewalk excavation fee, and the Section 245-22F minimum concrete replacement size of 10 by 10 feet.
4. Town of Smithtown Code, Chapter 322 Zoning, Supplementary Use and Building Regulations — Source of Section 322-15A(8) limiting paved surfaces to 25 percent of required yards, Section 322-25 requiring on-site stormwater disposal per the Town Engineer, Section 322-13A on fence and wall heights, Section 322-13E on retaining wall setbacks and Section 322-12B on accessory structures in required yards.
5. Town of Smithtown Code, Chapter 248 Subdivision of Land, Article XIII Street Improvements — Source of Section 248-37F(1) requiring sidewalks four inches thick and at least four feet wide of one-course concrete with six inches across driveway aprons, Section 248-37F(2) locating sidewalks within the right-of-way, and Section 248-37C(2) requiring integral concrete curb and gutter where gradient exceeds 4 percent.
6. Town of Smithtown Code, Chapter 112 Building Construction — Source of Section 112-10 requiring a building permit, the Section 112-10A exemption covering ordinary non-structural repairs and detached sheds of not more than 144 square feet and 12 feet in height, and Section 112-26 requiring a permit before a retaining wall, sea wall or bulkhead is constructed, altered, removed or demolished.
7. NRMCA CIP 6 - Joints in Concrete Slabs on Grade — Source of the joint spacing rule of 24 to 36 times slab thickness with a practical maximum of 15 feet, the minimum joint depth of one quarter of slab thickness and not less than one inch, the 4 to 12 hour saw-cut window, the panel aspect ratio limit of 1.5 to 1, and the guidance on premolded filler for isolation joints.
8. NRMCA - Criteria for Freeze-Thaw Resistant Concrete Mixtures — Source of the exposure class table: F1 at 3,500 psi, 0.60 water-cement ratio and 4.5 percent air; F2 and F3 at 4,500 psi, 0.45 and 6.0 percent air for No. 57 aggregate. Also the source of the roughly 88 percent critical degree of saturation and the statement that scaling is exacerbated in the presence of deicing salts.
9. USDA NRCS Official Series Description - Riverhead Series — Source of the soil description used throughout this site: very deep, well drained soils formed in glacial outwash derived primarily from granitic material, with saturated hydraulic conductivity high in the solum and very high in the substratum, mapped on outwash plains, valley trains, beaches and water-sorted moraines including Suffolk County, New York.
10. New York Department of State - RCNYS Technical Bulletin, Residential Exit Doors, Stairs and Landings — Source of the stair geometry cited on the steps and stoops page: riser height not more than 8 1/4 inches under Section R311.7.5.1, tread depth not less than 9 inches under Section R311.7.5.2, landings not less than 36 inches deep under Section R311.7.6, and handrails on not less than one side of a flight with four or more risers under Section R311.7.8.
11. U.S. Geological Survey - Surficial Geologic Map of Long Island — Source of the moraine and outwash distinction used on this site: two terminal moraines running east to west across Long Island with till beneath them, and stratified outwash sand and gravel deposited between and south of them. Used to explain why base preparation behaves differently on the north shore than on the interior of the Town.