Living near the water is a dream, but when it comes to construction, especially in a liquefaction zone or an Environmentally Critical Area (ECA), that dream quickly turns into a maze of regulations, permits, and engineering challenges.
Recently, we helped a family rebuild an old deck, and the project became a perfect example of how to navigate bureaucracy while building a safe, reliable structure that doesn’t lose its charm.
When “just replacing an old deck” isn’t that simple.
A homeowner reached out to us to replace a deck her late husband had built decades ago. She wanted to keep everything as close to the original as possible, but the problem was that the rules had changed significantly since then.
Here’s what we were working with:
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The house is in a liquefaction zone, which means the soil is unstable and requires careful engineering solutions.
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Modern building codes no longer allow putting a new deck on old concrete blocks.
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The city requires permits, reports, and inspections, which only added to the complexity of the project.
The goal wasn’t just to build a deck; it was to make sure the new one met all the updated requirements while still capturing the spirit of the original.
How Did We Solve This?
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A Reliable Foundation
The old deck was supported by concrete pads buried in sand—certainly not up to modern standards.
We brought in a geotechnical engineer to take a soil sample and determine what kind of foundation we could rely on. The solution was to drive 22-inch piles deep into the ground with a hydraulic hammer until they reached a solid soil layer. Now, the deck stands on a strong foundation that won’t sink or wash away with the tides.
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Navigating Bureaucracy: Getting Through the Permitting Process
Securing a permit was its own challenge. We had to go through multiple steps:
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A Pre-Application Site Visit (PASV) from the Seattle Department of Construction & Inspections.
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A geotechnical report, which was critical for getting the approval.
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Coordination with utilities, as the new deck’s supports conflicted with an existing gas line, so we had to move it.
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A sewer inspection before and after the construction to ensure no damage was done.
While this added time to the process, we’re well-versed in navigating this red tape and made sure the homeowner’s experience was as smooth as possible.
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Modern Materials for a Durable Deck
Once the permits were secured, we began construction. We selected materials designed to withstand the harsh conditions of rain, wind, and saltwater:
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Vintage Coastline decking, which is moisture-resistant and comes with a 50-year warranty—no painting required.
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G-Tape, a black waterproof tape applied to all horizontal framing surfaces to prevent decay and double the lifespan of the deck’s frame.
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Glass railings, ensuring that the ocean view remained unobstructed.
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Engineered beams, which allowed us to create a 22-foot span without extra posts, keeping the space open and airy.
What Did We End Up With?
Beyond the deck, we also rebuilt the front walkway, giving the property a fresh new look. While we could have added a few more features, like wrapping the posts or creating a paved area beneath the deck, the focus was on preserving the history of the home while creating a structure that is safe, durable, and built to last.
Want to Build a Deck in Seattle? Here’s What You Need to Know:
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Geotechnical study: If your site is in a liquefaction zone, this is essential.
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Pre-Application Site Visit (PASV): Without this, your project won’t get approval from the city.
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Utility coordination (SPU): Sometimes, relocating gas or water lines is necessary.
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Use moisture- and salt-resistant materials: Investing in quality materials now means less maintenance later.
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Work with professionals who know the system: Having experienced contractors can make all the difference.
If your property is in a Liquefaction Zone or ECA, don’t worry. We know how to handle the challenges and provide effective solutions. Reach out to us, and we’ll help you build a reliable, beautiful deck that can withstand any conditions.