Deck Questions From Kent Homeowners
The permit line, the guard rule, footings in local ground, materials, moss, timing, and what a deck is worth at sale. Each answer stands on its own; the linked pages go deeper.
Permits and Code
When does a deck need a permit in Kent, WA?
A deck needs a building permit in Kent unless it meets every part of the standard exemption: 200 square feet or less, no more than 30 inches above grade at any point, not attached to the house, and not serving the exit door. King County's list, for unincorporated addresses, exempts only uncovered decks 30 inches or lower on lots without critical areas. Kent's permit center handles city addresses and notes that exempt work still has to follow the code. The new deck page walks through the application.
How high does a deck railing have to be in Washington?
A guard is required on any open side of a deck more than 30 inches above the floor or grade within 36 inches of the edge, and it has to be at least 36 inches high under the 2021 Washington State Residential Code. Openings cannot pass a 4-inch sphere, and the top rail has to resist a 200-pound load. A guard that moves when leaned on is a repair with a code reason behind it.
How deep do deck footings go in Kent?
Exterior footings go at least 12 inches below undisturbed ground under the state code, and deeper where that depth does not reach solid bearing. On East Hill that usually means digging through the topsoil to the dense glacial till; on the valley floor it means a wider pad on soft silt. The state code lets a freestanding deck skip the frost-depth rule, but the bearing rule still applies, and the inspector looks at the holes before the concrete goes in.
Materials and Weather
Cedar or composite for a deck in Kent?
Composite lasts longer in Kent's wet climate and needs only a rinse; cedar costs about $10 to $20 less per square foot, looks better to many owners, and needs cleaning and resealing every two years or so to reach its 15-to-25-year life. Shaded, north-facing, or tree-covered decks favor composite or PVC. The cost guide runs the twenty-year arithmetic.
Why does my deck grow moss every winter?
Moss needs shade and moisture, and a Kent deck under trees or on the north side of a two-story house has both from October to April. On cedar the growth holds water against the wood and speeds rot; on composite it sits on the surface. A stiff brush, a deck cleaner, and better airflow under the deck do more than any single treatment, and a pressure washer on high does damage that outlasts the moss.
When is the best time of year to build a deck in Kent?
Quotes in late winter get the first spring slots, and a permit filed in February or March is usually approved before the dry season. Builders in south King County are busiest from May through September. Decks get built in the rain too; footings and framing do not mind it, and a winter build often means a shorter wait and a deck ready for the first dry weekend.
How long does a deck last in the Kent area?
Regional builders put cedar at 15 to 25 years with maintenance, capped composite at 20 to 30 or more, and PVC at 30 to 50. The frame under any of them is pressure-treated lumber whose life depends on drainage: taped joists, a flashed ledger, and posts on standoff bases can outlast the boards, while a frame that stays wet fails in the same 15 to 20 years regardless of what is on top. See deck replacement for what an old frame usually shows.
Rebuilding and Resale
Can I replace the boards and keep the old frame?
Resurfacing works when a builder has confirmed from underneath that the joists, beam, ledger, and posts are dry and solid, and when the joist spacing suits the new boards; composite needs 16-inch centers or closer, and many 1980s decks were framed at 24. It costs about $20 to $50 per square foot. If the frame fails the check, the resurfacing money is better put toward a replacement.
Does a deck add value to a house in Kent?
A permitted, sound deck is an asset at sale in a market where most buyers expect outdoor space, and an unpermitted or rotting one is a negotiating point against you. National remodeling surveys usually show a wood deck recovering a large share of its cost at resale, and a permit on file is what lets a buyer's inspector sign it off without a fight. A covered deck extends the season and the appeal further.