North Deering, Portland farmhouse with AZEK composite decking by Cardinal Exteriors

Composite & PVC Decks in Portland, Maine

Composite & PVC Decks for Portland homes from a family-owned Portland company. An owner measures on site and writes a fixed-price proposal.

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Composite & PVC Decks for Portland homes

Composite and PVC boards fit Portland conditions well. Salt spray on the waterfront and islands, shade from mature trees in older neighborhoods, and months of snow sitting on the surface all break down wood decking, which then needs sanding and restaining that composite does not. For island cottages used mostly in summer, a low-upkeep deck means arriving in June to boards that only need a wash.

Composite still needs good design. Boards expand and contract with temperature, so gaps at ends and edges must suit Portland's swings from summer sun to below-zero nights. Under the surface, the framing is usually pressure-treated lumber and has to meet the same code and footing requirements as any deck. Shaded yards in Deering Center or along wooded lots can grow mildew on any surface, so capped boards, good airflow under the deck and enough spacing between boards help. Darker colors get hot in full sun on a harbor-facing deck, which matters for bare feet. Railings in composite, aluminum or cable can keep a water view open while meeting guard height rules, a common choice on Munjoy Hill and island lots.

Composite deck furnished as an outdoor living space backing onto woods

How a Deck Structure Is Built

  1. Footing — poured below Maine’s frost line so winter heaving cannot move it
  2. Post — carries the beam load down to the footing
  3. Beam — spans between posts and carries the outer ends of the joists
  4. Ledger — bolted to the house framing, with flashing that diverts water away from the wall
  5. Joists — span from the ledger to the beam, sized and spaced to the decking and the load
  6. Decking — the walking surface, fastened on top with spacing for drainage
Aerial view of a new multi-level wood deck with a pergola and hot tub surround

Portland housing at a glance

Portland has roughly 36,600 housing units, and the American Community Survey estimates a median year built of 1946. About 46 percent predate 1940 and about 61 percent predate 1960, while only about 16 percent date from 1960 to 1979 and about 11 percent from 2000 or later. Owners occupy about 47 percent of occupied homes, and single-family detached houses make up only about 36 percent of the stock, so multi-unit buildings are the norm rather than the exception. After the Great Fire of 1866 the peninsula was rebuilt largely in Victorian and Italianate styles, and wood-framed triple-deckers fill much of the older residential grid. Off the peninsula, Deering and the outer neighborhoods run to capes, colonials and mid-century houses. The census also counts nearly 1,900 seasonal units, many of them island cottages in Casco Bay.

Permits and design review in Portland

Building permits in Portland go through the city's Permitting and Inspections Department, which handles permits, licensing and inspections in one office. A new deck is structural work and needs a building permit; ask the department whether a given roof, siding or window job needs one before work starts. Portland also has a strong historic preservation ordinance. Properties in local districts including the West End, India Street, Congress Street, Deering Street, Stroudwater and the Old Port waterfront need a certificate of appropriateness for exterior alterations, reviewed by preservation staff or the Historic Preservation Board. Waterfront and island lots may also fall under shoreland zoning.

Weather and exposure in Portland

Portland sits on a peninsula in Casco Bay, and exposure changes block to block. Houses on the eastern and western ends of the peninsula, along the harbor and on the islands take wind straight off the water, while inland neighborhoods such as Deering and Stroudwater are more sheltered. Snowfall averages about 69 inches a year, but the city has seen seasons as light as 30 inches and as heavy as 150. Severe nor'easters arrive in winter with wind-driven rain and snow that finds any gap in old clapboard, trim or window casing. Repeated freeze and thaw works on paint, caulk and shingles, and salt air on the waterfront and islands speeds corrosion of fasteners, flashing and exposed metal.

Portland at a Glance

What the housing stock and local code enforcement mean for a siding, window, roofing or deck job here.

68,408

Population (ACS estimate)

Median year built: 1945

Homes built before 194047%

Original wood clapboard or shingle siding, wood-sash windows and multi-layered roofs are common here.

State Building & Energy Code (MUBEC)

Enforced — population over 4,000

EPA Lead-Safe Rule (pre-1978 homes)

Applies to at least 60% of homes here

Historic District

Exterior work may need design review

Shoreland Zoning

Applies near the water

Permits

Permitting and Inspections Department, City of Portland

Codes & Permits for Composite Decks in Portland

In Portland, exterior-work permits come from the Permitting and Inspections Department, City of Portland (389 Congress St, Room 315, Portland, ME 04101, 207-874-8703). With 68,408 residents, over 4,000, Portland is required to enforce the Maine Uniform Building and Energy Code (MUBEC). The West End, India Street, Congress Street, Deering Street and Stroudwater local historic districts require a certificate of appropriateness for exterior alterations, reviewed by the Historic Preservation Board.

  • Maine's adopted 2021 IRC (R507.2.2) requires plastic composite deck boards, stair treads, guards, and handrails to comply with ASTM D7032, and (R507.2.2.1) to be labeled with the allowable load and maximum allowable span determined under ASTM D7032 — meaning composite span limits come from the product's own ASTM D7032 listing/manufacturer data rather than the standard wood joist-span tables, and are often shorter, requiring closer joist spacing than an equivalent wood board. up.codes
  • Composite decking installation must follow both the code and the manufacturer's instructions (R507.2.2.5), so a given product's specific fastening pattern and joist spacing should be pulled from its ICC-ES evaluation report or manufacturer install guide, not assumed from a generic wood-deck spec. up.codes
  • Maine's Shoreland Zoning Act creates a regulated shoreland zone extending 250 feet (horizontal distance) from the normal high-water line of any great pond, river, or coastal wetland, and 75 feet from certain streams; the Act's stated purposes include protecting buildings and land from flooding/erosion and controlling water pollution, and it governs deck and other structure setbacks and the expansion of nonconforming structures within that zone (specific setback/expansion rules are set at the municipal-ordinance level under the state's model guidelines). maine.gov
  • By Maine law (25 M.R.S. §2373), 'the code must be enforced in a municipality that has more than 4,000 residents' (per the most recent federal census); municipalities at or below that population are not required to adopt/enforce MUBEC but may opt in locally, per the state's own program page: 'All municipalities with a population greater than 4,000 are required, by statute, to enforce the MUBEC. Municipalities with a population under 4,000 may choose to enforce the MUBEC.' mainelegislature.org

How Cardinal Exteriors Handles Composite Decks in Portland

  • Every ledger we attach for a composite and PVC decks job in Portland is flashed to Maine's adopted deck code, with corrosion-resistant metal or an approved nonmetallic alternative, not a bare lag bolt into siding.
  • We set every Portland deck's footings below frost depth and size them to the actual load, following Maine's adopted residential code rather than a rule of thumb.
  • Because Portland has coastal, lake or river frontage, Maine's Mandatory Shoreland Zoning Act may apply to work close to the water, which can affect setbacks on a rebuild.
  • Portland's population (68,408) puts it above the threshold where Maine law requires full MUBEC enforcement, so this job is inspected against that code as well as the local permit.
  • We file for composite and PVC decks permits at the Permitting and Inspections Department, City of Portland before work starts, not after.
Portland, ME
A Victorian home on Neal Street in Portland's Western Promenade Historic District, developed in the late 1800s with Second Empire, Italianate, Queen Anne and Shingle-style houses.
Street View © Google

What composite and PVC decks involves

Composite and PVC decking do not need staining, do not splinter, and resist rot, which is why they have become the default for new decks in Maine. Composite boards blend wood fiber and plastic under a protective cap; PVC boards are all synthetic and lighter. The North Deering farmhouse on this site got a rebuilt deck with AZEK composite decking. The framing underneath is still wood, so it is built to last as long as the boards on top.

  • Layout, size and board color are chosen with the owner at the estimate visit.
  • Footings and framing are built to code, with joist spacing that suits the board manufacturer's span rules.
  • Joist tape or flashing protects the tops of joists and the ledger.
  • Boards go down with hidden fasteners or color-matched screws and the expansion gaps the product requires.
  • Matching railings, stair treads, fascia and landings finish the deck.

Signs it is time

  • You are done staining and sealing a wood deck every year or two
  • The deck is in shade or near water where wood stays damp
  • You want a deck that stays barefoot-friendly with no splinters

What affects the price of composite and PVC decks

  • Composite versus PVC, and the product line
  • Deck size, height and shape
  • Railing system and stairs
  • Hidden-fastener versus face-screw installation
  • Footing and framing conditions

Every job is priced from a free on-site visit. Typical ranges for the trade are on our deck building page, and the details of this service are on the composite and PVC decks overview.

For a deeper walkthrough of materials, code details and photos, see our full Composite & PVC Decks: What Changes From Pressure-Treated Lumber guide.

Get a free composite and PVC decks estimate in Portland

Tell us about the house and what you want changed. One of the owners will call to set up a visit, measure, and write a fixed-price proposal. No pressure, no obligation.

Need it today?Call Mike (207) 408-5388

or Bob at (207) 252-0759