Your builder used ZIP System but didn't tape the seams. Here is why that matters

ZIP System, made by Huber Engineered Woods, is OSB sheathing with a factory-bonded facer that takes the place of housewrap. Its code approval comes from ICC Evaluation Service report ESR-1474, which accepts the panels as an alternative to the water-resistive barrier required by Chapter 7 of the International Residential Code. The report sets a condition: every panel seam must be sealed with ZIP System flashing tape, VP flashing tape or liquid flash. Bare seams leave the wall without a code-approved barrier behind the siding.

The report spells out how. Tape has to be centered within 1/2 inch of the seam, run at least 1 inch past T-joints and be pressed firmly so the adhesive bonds. Wrinkles are acceptable only if they don't open a path to the seam. The air-barrier rating in the report, 0.008 cubic feet per minute per square foot of leakage at 75 pascals, applies to walls with the 1/8-inch gaps between panels taped. Window and door openings, roof-to-wall joints and penetrations also need flashing.

Missing tape is easy to spot while the sheathing is bare: each seam should carry a continuous, flat strip. ESR-1474 also says Huber's installation instructions must be on the jobsite during installation, so an owner can ask to see them. Before siding goes on, ask the builder to tape every seam and flash every opening to those instructions, and walk the walls together afterward. Once cladding covers the panels, the same fix means taking siding off.