Set posts for the frost
A joint City of Spokane and Spokane County codes policy sets frost depth at 24 inches below finished grade unless a soils investigation supports a different depth. NOAA's engineering weather data for Spokane records about 72 freeze-thaw cycles a year. Posts set shallower than the frost line can heave, lifting fences and throwing gates out of alignment. Ask the contractor how deep they'll set posts, especially gate and corner posts, and how they'll shape footings to resist frost.
Snow loads
NOAA's data lists a 50-year ground snow load of 42 pounds per square foot for Spokane. Heavy snow piles against fences, especially where plowed or shoveled snow ends up. Snow and ice add weight and moisture to wood and can crack vinyl in cold weather. Consider where snow will be piled when planning fence lines and gates, and keep wood fences clear of long-term snow piles.
Cold and vinyl
Vinyl becomes more brittle in cold weather and can crack if hit. Choose a quality product with reinforced rails, and be careful with snow blowers and shovels near the fence.
Wood and moisture
Spring snowmelt keeps soil wet, and wood posts rot at ground level. Ground-contact-rated posts, gravel at the bottom of each hole, concrete or tamped gravel sloped to shed water, and keeping soil and mulch away from boards all help.
Wind
Storms bring wind that loads privacy fences. Board-on-board designs and stronger posts improve wind resistance.
Permits
The City of Spokane and Spokane County limit fence height in front yards and near corners, and taller fences may need permits. Check homeowners association rules as well.
Before you hire
Ask Spokane fence contractors how deep they'll set posts, how they'll handle snow and cold, which materials they recommend, whether a permit is needed, and what the warranty covers. Ask them to call in a utility locate before digging. Use L&I's contractor lookup to check their Washington registration, bond and insurance.
Gates
Gates suffer first when posts heave. Set gate posts deeper and larger than line posts, brace wood gates diagonally or use a steel frame, and choose heavy-duty hinges and latches. Check alignment after the spring thaw.
Maintenance
After each winter, check for leaning sections, loose boards, popped fasteners and rot at the base of posts. Re-stain wood periodically. Clean vinyl with a hose and soft brush, and touch up chips in metal coatings.
Neighbors
Talk to neighbors before replacing a shared fence, and confirm the property line.
Pets and wildlife
If you're keeping pets in or deer out of a garden, choose height and design to match. Snow can make a fence effectively shorter in deep winters.
Snow removal
Keep snow blowers and plows a little away from fences, since thrown ice and snow chunks can crack vinyl and split wood boards.
Stain and sealer
Stain wood fences in dry, mild weather in late spring or summer, so the finish cures before winter.