How to Install Deck Boards Guide for Eastern Washington Homeowners & Contractors
Choosing the Right Deck Boards for Eastern Washington’s Climate
If you’ve lived through a few winters in the Spokane area, Colville, or Kettle Falls, you already know our climate is tough on outdoor building materials. We swing from sub-zero cold snaps and heavy snow load in January to bone-dry, 95-degree summers with intense UV exposure. That combination — freeze-thaw cycling followed by months of high sun exposure — is exactly what causes deck boards to cup, split, and pull loose from their fasteners if the wrong material or installation method is used.
When customers come into our Airway Heights, Colville, or Kettle Falls locations asking what board to use, we usually walk through four main categories:
Pressure-Treated Lumber
Still the most affordable option and widely available. Make sure it’s rated for above-ground or ground-contact use depending on your framing, and plan on sealing it within the first year to prevent checking from our dry summer sun. Pressure-treated boards also require corrosion-resistant fasteners — regular steel screws will corrode quickly from the treatment chemicals.
Cedar
A favorite around the region for its natural rot and insect resistance and warm appearance. Cedar is softer than composite, so it dents easier, and it needs a UV-rated stain or sealer every 1-2 years here — our summer sun is harder on wood finishes than folks expect, even at our elevation.
Composite Decking (Trex, TimberTech, Fiberon)
Composite has become the go-to for homeowners who want a low-maintenance, dimensionally stable board that handles our freeze-thaw swings well. Installed costs typically run $28-$38 per square foot for standard composite lines, and $35-$50 per square foot for premium composite. No annual staining, and most modern composites resist moisture absorption far better than wood — a real advantage when snow sits on a deck surface for weeks at a time.
PVC / Capped Polymer Decking
The premium option, running $38-$55 per square foot installed. PVC boards handle moisture better than anything else on the market and hold up well to our UV exposure, making them a smart choice for decks that don’t get much winter sun to dry out.
Whatever you choose, stop by any of our three locations and we can walk you through samples and help you compare based on your specific site conditions — a shaded deck in Kettle Falls behaves differently than a south-facing deck out in Airway Heights.
Spokane-Area Building Codes and Permit Requirements
Before you buy a single board, it’s worth understanding what the local codes require. Spokane city and county both follow the International Residential Code (IRC), and deck construction specifically falls under IRC Section 507. The City of Spokane also publishes a Prescriptive Residential Deck Construction Guide that spells out joist spans, ledger attachment, and fastening schedules based on the current adopted IRC edition.
When You Need a Permit
As a general rule in the Spokane area, you’ll need a permit if your deck is:
- More than 30 inches above grade at any point
- Larger than 200 square feet
- Attached to your house
Freestanding, low decks under those thresholds may be exempt from permitting, but they still need to be built to sound structural standards. Permit fees in our area typically run $100-$500 depending on deck size and scope, and most projects require two to three inspections — footing, framing, and final.
Code Details That Affect Board Installation
- Guardrails: Minimum 36 inches high for residential decks, with baluster spacing no more than 4 inches to prevent entrapment.
- Stairs: Minimum 36 inches wide, risers no more than 7¾ inches, treads at least 10 inches deep.
- Ledger attachment: Must be lag-bolted or through-bolted to the house rim joist — never nailed — with continuous metal flashing to keep water out.
That ledger detail matters more than people think. A poorly flashed ledger is one of the top causes of deck failure in our region, because water gets trapped against the house framing, rots it out from behind, and eventually the whole deck board surface starts to feel spongy or uneven. If you’re not sure what your local jurisdiction requires, our staff at any Builders Supply location can point you toward the current prescriptive guide and help you figure out what applies to your project.
Step-by-Step: Installing Deck Boards Correctly
Once your framing, ledger, and joists are inspected and ready, here’s how we recommend approaching the actual board installation.
1. Plan Your Board Layout First
Before you drive a single screw, dry-lay a few rows or measure out your full run. Decide where seams will land, whether you’ll use a picture-frame border or breaker boards, and how the pattern will look around stairs and posts. Skipping this step is one of the most common mistakes we see — homeowners end up with a 2-inch sliver of board at the far edge because they didn’t plan the layout in advance.
2. Choose Your Board Direction
Most decks in our area run boards perpendicular to the joists, which is standard for a reason — it sheds water efficiently and works with typical 16-inch on-center joist spacing. Diagonal patterns look great but usually require joists spaced at 12 inches on-center and generate more waste, so budget for extra material if you go that route.
3. Leave Proper Gaps for Drainage and Expansion
For wood boards, leave about 1/8″ to 3/16″ between boards to allow for drainage and seasonal movement. This is especially important here because our winter moisture followed by summer drying causes wood to expand and contract more than in milder climates. For composite and PVC boards, always follow the manufacturer’s specific gapping chart — Trex, TimberTech, and Fiberon all have slightly different requirements, and getting it wrong can cause buckling in July or trap ice and debris in January.
4. Use the Right Fasteners
This is where a lot of DIY decks go wrong. Pressure-treated lumber requires hot-dipped galvanized or stainless steel fasteners — standard interior screws will corrode within a season or two from the chemical treatment. For composite and PVC boards, use the hidden fastener clip system or face screws specifically approved by the manufacturer; using the wrong fastener can void your product warranty. If your deck sits in a spot that collects moisture or snowmelt longer than the rest of your yard, stainless steel is worth the upcharge.
5. Fasten Boards Working From the House Out
Start at the ledger and work outward, checking your gap spacing every few rows with a spacer tool or scrap piece of the same thickness. Pre-drill near board ends to prevent splitting, especially with cedar. Stagger seams so they don’t line up row after row, which both looks better and spreads structural load more evenly.
6. Trim and Finish the Edges
Once your field boards are installed, snap a chalk line and trim the overhanging ends in one clean pass rather than cutting each board individually beforehand — you’ll get a straighter, more professional edge. Cap with a fascia board if your design calls for it.
7. Seal or Finish Wood Boards Promptly
If you installed cedar or pressure-treated lumber, don’t wait too long to apply a UV-rated sealer or stain — our summer sun will start drying and checking exposed wood surfaces faster than folks expect, sometimes within the first season. Composite and PVC boards don’t need this step, which is a big part of why they’ve become so popular across Eastern Washington.
Common Mistakes We See Across Eastern Washington Decks
After decades serving builders and homeowners in Airway Heights, Colville, and Kettle Falls, we’ve seen the same handful of mistakes come up again and again:
Skipping the Permit
Building a deck over 30 inches high without a permit can create real headaches at resale time, and in some cases the county can require you to tear out non-compliant work. It’s worth the paperwork.
Tight Board Spacing
Boards installed with little or no gap trap moisture and debris — pine needles and leaves are a real problem in wooded areas around Colville and Kettle Falls — and that trapped moisture accelerates rot and freeze damage.
Wrong Fasteners
Using standard screws with pressure-treated lumber, or non-approved fasteners with composite decking, leads to premature corrosion, staining, and voided warranties.
Poor Ledger Flashing
A nailed, unflashed ledger board is a slow-motion structural failure. Water gets behind the board, the rim joist rots, and eventually your entire deck structure — boards included — becomes unsafe.
No Ventilation Underneath
Skirting a deck tightly without vents traps moisture underneath, which keeps the underside of your boards wet far longer than they should be. Always leave ventilation gaps in skirting.
Ignoring Snow Load in Framing
Our region gets real snow load, and undersized joists or beams lead to a bouncy, unsafe deck surface regardless of how nice the boards on top look. Always build to the prescriptive span tables or get an engineered design for anything unusual.
DIY vs. Hiring a Pro — and What It Costs
Plenty of homeowners in our area successfully DIY a deck board installation, especially for lower, simpler projects.
Good DIY Candidates
- Decks under 30 inches high and under 200 square feet (often permit-exempt)
- Simple rectangular layouts without complex stairs
- Board replacement on an existing, sound structure
- Refinishing or resealing existing wood decking
When to Call a Professional
We recommend hiring a licensed local contractor when your deck is elevated more than 30 inches, attaches to your house via a ledger, involves composite or PVC systems with specialized hidden fasteners, or includes custom patterns and complex stairs. Licensed contractors in Washington carry the required bonding and insurance, and they’re set up to handle the inspection process smoothly.
What It Typically Costs
Based on regional pricing for the Pacific Northwest:
- Cedar decking, installed: roughly $18-$28 per square foot
- Standard composite (Trex-level), installed: roughly $28-$38 per square foot
- Premium composite (TimberTech-level), installed: roughly $35-$50 per square foot
- PVC/capped polymer, installed: roughly $38-$55 per square foot
For a full project scope: a small 100-150 square foot deck with basic rail typically runs $7,000-$15,000 installed, a mid-size 200-300 square foot deck with standard rail runs $15,000-$30,000, and a large 400+ square foot deck with stairs and premium railing can run $35,000-$60,000 or more. These figures don’t typically include demolition of an old deck (often $3-$8 per square foot) or permit fees.
Material choice is the biggest cost driver, but complexity — multiple levels, curves, built-in benches, premium railing — adds up fast in labor. Over a 15-20 year span, wood decks often cost more in total ownership once you factor in staining and repairs, which is why many of our customers choose composite even with the higher upfront price.
Ready to get started on your deck project? Builders Supply & Home Center stocks pressure-treated lumber, cedar, composite decking, fasteners, and all the hardware you need at our Airway Heights, Colville, and Kettle Falls locations. Our staff knows the local codes and climate challenges firsthand, and we’re happy to help you plan a deck that holds up to everything Eastern Washington weather throws at it. Browse our full selection online at https://bldrsupply.epicor-inet.com/departments or stop by your nearest store to talk through your project with our team.