Novato Police Department Water Infiltration Project

The work to be done includes but is not limited to: Demolition & Preparation.Removal and safe storing (in the NPD garden area located to the left of the main entrance) of unattached benches and deck structures. Stripping the existing deck down to the structural concrete core. Mechanically clean the concrete surface to remove old adhesive, contaminants, and debris. Clean and seal all surface cracks and alert the City Engineer of any un-viewable substrate defects. Confirm new system thickness against the main door and training room entry doors thresholds before demolition. Adjust aluminum thresholds to guarantee a smooth, ADA-compliant transition. Sawcut and remove the first top step of the main staircase and cut the bottom of its 3 support poles (to be remounted later). Sawcut and remove 12 inches into the ADA ramp entry point to accommodate the under-deck drainage system. Sawcut and remove 12 inches into the flagpole base to accommodate the under-deck drainage system. Clear and grub designated bushes as outlined in the pre-bid walk. Waterproofing System.Supply and install a Duro-Fleece Plus 80-mil PVC (or approved equal) fleece-backed membrane. Bond the membrane to the concrete substrate using POLYSET Commercial Roofing Adhesive (CR-20) or an approved equal. Hot air weld all seams to form a completely watertight seal. Terminate all penetrations and edges according to strict manufacturer specifications. Install the membrane over the patio edge, fastening it to the top of the CMU wall using a Duro-Last 4-inch fascia bar system (or approved equal). Install second membrane at the exterior wall and trench drain (sketch to be included with bid documents). Pedestal-Supported Porcelain Paver Deck.Build a floating deck system over the PVC membrane using Buzon U-TABS 2mm spacer tabs and Buzon U-PAD 3mm protection mats (or approved equals). The assembly relies on a dry-laid design with no mechanical fasteners piercing the waterproofing layer. Supply and lay 24" x 24" x 2cm exterior-grade porcelain pavers engineered for elevated plaza decks. NPD staff must review and approve the paver color before purchase. Maintain a consistent grid appearance across the 1,500 sq. ft. layout, balancing proper drainage and slope compensation across the patio's 1.3% grade. Secure the patio edge using a glued Schluter Systems aluminum L-shape tile trim (or approved equal). Perimeters and building alcoves do not require baseboard or skirting tiles; instead, the Duro-Fleece PVC will run beneath all wall flashing and be secured by the factory fascia bar.

• Perimeter Trench Drainage System.Install a 140-linear-foot, 4-inch perforated drainpipe wrapped in geotextile. 4-inch EZ Drain prefabricated trench drain system optional. Begin the trench drain run at the left of the NPD patio at a depth of 12 inches. Slope the pipe at a 1% grade across the 140-foot length, terminating at a depth of 20 to 29 inches. Terminate trench drain at the sump pump vault to the right of the patio. Incorporate 4 clean out grates evenly along the 140-foot run for long-term maintenance access.
• Amenities & Bench Re-installation.Re-install the benches and deck structures onto the finished deck using Duro-Last U-Anchor U2000 attachments (or approved equal). Hot-air weld the U-anchors directly into the primary PVC deck membrane to preserve the buildings watertight integrity. Quality Assurance & Warranties.The City of Novato will conduct random phase inspections throughout construction. Formal material and quality assurance milestones must be scheduled and verified by a non-third-party Duro-Last factory representative before subsequent trades proceed. Provide a 20-year Manufacturers Warranty from the date of Substantial Completion. The warranty must be an NDL (No Monetary Limitation) standard or custom form covering the PVC membrane, flashings, welds, fasteners, edge transitions, accessories, and substrate preparation.