Under Deck Waterproofing in Eastside King County.

Transform the space beneath your deck into a dry, usable area with professional under deck waterproofing by Petra Decks. Perfect for Sammamish, Snoqualmie, Kent, Bellevue, Issaquah, Auburn, West Seattle and surrounding Eastside King County homes, our waterproof systems are built to withstand the Pacific Northwest’s wet climate—adding value and year-round function to your outdoor space.

Custom Under-Deck Waterproofing – Protect & Maximize Your Outdoor Space

What Is Under Deck Waterproofing?

Under deck waterproofing involves installing a drainage system that captures rainwater between deck boards and channels it away, keeping the area beneath your deck dry.

💧 Create a Dry Outdoor Living Area

Turn the space below your deck into a patio, lounge, storage area, or covered walkway—no more dripping water or soggy surfaces.

☔ Protect Your Home’s Structure

Waterproofing helps prevent water damage, mold, rot, and wood deterioration beneath your deck.

🧼 Low Maintenance & Durable

Our systems are designed for easy upkeep and built with materials that last through years of Washington weather.

Frequently Asked Questions

What materials do you use for custom deck designs?

We specialize in crafting durable and visually stunning custom decks using high-quality materials like composite, hardwood, cedar, and PVC. Our expertly designed decks are built to withstand the elements while enhancing your outdoor space with style and functionality. Whether you prefer the low-maintenance benefits of composite decking or the natural beauty of hardwood and cedar, we tailor each design to match your unique preferences and lifestyle needs.

Can I see a sample of the materials you use?

Yes! We offer a mobile showroom experience, bringing samples of all our premium deck materials—including composite, hardwood, cedar, and PVC—right to your doorstep. This allows you to see, feel, and compare different options in person, so you can confidently select the perfect materials for your custom deck.

How long does the deck construction process take?

The deck construction timeline depends on factors such as project complexity, size, and weather conditions. On average, our expert team completes deck installations within a few days to a couple of weeks from start to finish. We ensure efficient project management while maintaining the highest standards of quality, durability, and craftsmanship

Is the decking and railing material covered under warranty?

Yes! The decking and railing materials we use are covered by manufacturer warranties, which vary depending on the brand and type of material. Many composite and PVC decking products come with warranties ranging from 25-50 years to lifetime coverage, while wood decking may have more limited protection. We’ll provide detailed warranty information for your chosen materials and ensure you have peace of mind with a durable, long-lasting deck

Do you handle all necessary permits for deck construction?

Yes! We handle all necessary permits and ensure full compliance with local building codes and regulations, making the construction process smooth and stress-free. Our expertise in Eastside King County permit requirements guarantees that your deck is built safely, legally, and to the highest industry standards. Let us take care of the paperwork so you can focus on enjoying your new outdoor space!

Get a Free Estimate for Under Deck Waterproofing

Contact Petra Decks today to schedule your free consultation.
Let’s create a dry, functional space under your deck—designed to last through every season.