Composite Deck Builder in Garden City, ID

What decides the composite board on a Garden City lot?

Two very different lots, often a few blocks apart. Along the north bank of the Boise River and on the streets around the River Club, decks sit under black cottonwoods and willows that hold shade most of the day and shed seed fluff, catkins and leaves from spring into fall. On newer infill lots off Chinden Boulevard, a deck may have no tree near it at all and take sun from noon until sunset. One board rarely suits both, so the first site visit records which situation the deck is in before a sample box gets opened.

On the shaded lots the goal is drying. A fully capped board with side gaps kept open lets debris fall through instead of packing into the joints, where it holds water against the cap and feeds mildew. On the sunny lots the goal is surface temperature. NOAA's 1991–2020 normals for the Boise Air Terminal, a few miles southeast, show about 55 days a year at 90°F or warmer and a July average high of 92.7°F, and a charcoal board on a west-facing infill deck is hard to stand on barefoot by late afternoon. We leave samples on the site and check them at four o'clock before the order goes in, and on the hottest exposures a pergola over the west end of the deck does more than any board color.

Can a composite deck be built in the Garden City floodplain?

Yes, and most Garden City composite decks are. The floodplain adds paperwork, which the Garden City deck permit rules walk through, but it does not rule out a deck. What it changes is how the deck is put together, and with composite the question is the frame and the space under it, since the boards themselves don't mind getting wet.

Capped boards shed water and silt, but the frame under them is still wood, and in a high-water spring the soil beneath a riverside deck can stay wet for weeks. We specify posts and any member close to the soil as ground-contact treated lumber, use hot-dip galvanized or stainless connectors, and leave the underside open to air. The city's floodplain site-plan checklist asks for every area to be cleared, cut, graded or filled, and grading or fill needs its own Floodplain/Floodway Development Application. A deck that sits on posts and needs no fill keeps that part of the process short.

Skirting is where owners get surprised. Solid skirting around a low deck boxes in a space that floodwater can fill, and for buildings with enclosed space below the base flood elevation, Garden City's checklist asks for the enclosed area and the size and location of flood openings. Open lattice or wide-gapped horizontal slats avoid creating anything that looks like an enclosure and let debris wash through. Whether a particular skirting design counts is a question for the city's floodplain staff at floodplain@gardencityidaho.org, and we ask before building it.

Composite decks on Garden City townhomes and infill

On newer two- and three-story homes, the composite deck is often a second-floor platform a few feet from a side property line. Garden City's plan checklist wants decks drawn on the site plan with setbacks to every property line and any easements, and a stair section that dimensions treads, risers, headroom, handrails and guards. Under the 2018 IRC, a guard is required once the walking surface is more than 30 inches above grade, must be at least 36 inches tall, and cannot let a 4-inch sphere pass. On a narrow lot the setback lines usually settle the deck's depth long before the board color is chosen.

Privacy screens are the common add-on, usually on the side that faces a neighbor's windows. A screen is part of the guard and framing design, so it goes on the drawings rather than getting bolted on later. If the deck carries lights, the city wants outdoor lighting and its shielding drawn on the site plan and the elevations, while the electrical permit comes from the state rather than the city. In the Surel Mitchell Live-Work-Create District, a deck on a live-work unit stays on the residential application only while business use is under 10 percent of the structure, so ask which application applies before drawing a deck that doubles as a studio patio.

Can composite boards go on an older Garden City deck frame?

Sometimes, once the frame has been opened and checked. Decks on the small older houses off Chinden and Glenwood were usually framed for wood boards, and capped composite lines typically call for joists at 16 inches on center for straight boards and 12 inches for diagonal layouts, a requirement the IRC passes through by deferring to the manufacturer. We measure joist spacing, probe the joist tops and look behind the ledger before quoting a board swap.

Those houses bring a second check. Garden City's application asks whether the home was built before 1978 and, if it was, for a lead certification number. EPA's Renovation, Repair and Painting rule requires certified firms and lead-safe practices for paid work that disturbs paint in pre-1978 homes, and pulling painted trim to flash a ledger is exactly that kind of work. A freestanding frame set beside the wall avoids disturbing the paint. If the old ledger or posts have failed, the honest answer is deck replacement in Garden City rather than new boards on a tired frame.

Published 2026 installed ranges run about $40–$62 per square foot for capped composite and $55–$78 for PVC, against $25–$40 for pressure-treated pine; these are market figures, not a Valley Decks price. The composite deck cost guide breaks them down by component, and composite vs. PVC decking explains when the wetter river lots justify PVC.

How a Garden City composite deck gets permitted

1. Look up the parcel's flood status and measure to the riverbank or Greenbelt before design, so the riparian strip is known.
2. Pick boards from samples tested on the site; get any association approval in writing.
3. Draw the site plan with setbacks, easements, nearby waterways including irrigation laterals and ditches, and the floodplain line, plus framing matched to the board's span rating.
4. State the design criteria on the plans. The city prints a 24-inch frost depth, 40 psf floor live load and 1,500 psf soil bearing only as an example; the reviewer confirms the values for the project.
5. File the full package, including the notarized Affidavit of Legal Interest, at the Development Services window or by email. Incomplete applications are not accepted.
6. Schedule inspections by the city's contracted inspectors through the hotline at 208-472-2920.

Garden City's permit-exemption text (code section 7-2-3 F) is not published online, so we never assume a low composite deck is exempt; Building Services at 208-472-2921 confirms it per project. To compare the same work under other rules, see composite decking in Boise or Eagle composite decks, and request an estimate when you want the lot checked.