Why ZIP System Sheathing and Proper Flashing Matter in a Custom Home

By Greg MacPherson | MacPherson Building LLC

When you’re building a custom home, it’s easy to get excited about the kitchen, flooring, and exterior finishes. But some of the most important work happens before any of those materials are installed.

The layers behind the siding help protect your home from water, reduce drafts, and control how much conditioned air escapes. That’s why I put so much importance on the building envelope—and why I like ZIP System sheathing, stretch tape, and liquid flashing.

Each product has a job. The value comes from getting them to work together.

It starts with a continuous barrier

The building envelope separates the conditioned interior of your home from the outdoors. Insulation slows heat transfer, while air sealing limits uncontrolled air movement. A well-built home needs both.

ZIP System wall sheathing combines structural panels with a factory-applied water-resistive barrier. When the panel seams and transitions are properly sealed, the system also creates a continuous air barrier.

Having that protective layer attached directly to the sheathing gives us a solid surface to connect our flashing details to. The goal is continuity: following the barrier across the wall and keeping it connected through corners, openings, and changes in materials.

Why stretch tape is so useful

A straight panel seam is relatively simple to tape. A window sill with corners turning in several directions takes more attention.

ZIP System stretch tape can conform around those shapes. At a window sill, that allows the flashing to turn up the sides of the opening and out onto the wall face with fewer separate pieces and cuts.

That matters because every cut, overlap, and corner is another detail that needs to be sealed correctly. Stretch tape makes it easier to create continuous protection in places where ordinary flat tape can be difficult to fit.

It is especially useful at sill corners, curved openings, and certain penetrations. Proper coverage and rolling are still essential—the ability to stretch doesn’t replace careful installation.

Where liquid flashing makes a difference

Liquid flashing gives us another way to handle complicated areas.

ZIP System liquid flash is applied and spread into a membrane that follows the shape of the surface. It can be useful around pipe penetrations, inside corners, rough openings, and approved transitions between different materials.

What I like about it is the ability to work it into irregular details where fitting tape neatly can be challenging.

Application thickness, surface preparation, temperature, and compatibility all matter. It needs to be installed as a proper flashing membrane, following the manufacturer’s details.

Stretch tape and liquid flashing give us options for different conditions. Using the right product in the right location helps connect the protective layers throughout the home.

What a better-sealed envelope means for you

Reducing uncontrolled air leakage can help reduce drafts, improve comfort, and lower the energy needed to heat and cool a home. Air sealing also helps limit moisture carried into building assemblies by leaking air.

Water management requires its own attention. Window and door flashing needs to direct water back outside, with drainage paths kept open according to the installation details.

A tightly built home also needs planned ventilation. Fresh air should come through a properly designed ventilation system, with appropriate filtration and humidity control, rather than through random gaps in the building.

How this fits Rhode Island’s updated energy code

Rhode Island’s current energy code adopts the 2024 International Energy Conservation Code. That makes the performance of the complete building envelope an important part of planning a new home.

Under the 2024 IECC’s prescriptive requirements for Rhode Island’s climate zone, the air-leakage limit is 3 air changes per hour at a test pressure of 50 pascals, commonly written as 3 ACH50. This is a controlled test measurement, not the home’s everyday ventilation rate. Other compliance paths have their own requirements.

Carefully sealed sheathing, openings, and transitions support that air-leakage goal. ZIP System is one approach to achieving it; the code does not require this particular brand.

The complete home still needs the appropriate insulation, windows, mechanical systems, ventilation, and testing. Standard ZIP sheathing handles air and water control; ZIP System R-sheathing is a separate product that adds exterior insulation.

The installation is what brings it together

Good materials give us the tools, but the details determine how well the system performs.

Tape needs proper surface contact and rolling. Wrinkles and gaps need attention. Liquid flashing needs the specified coverage. Connections at the foundation, windows, doors, and ceiling or roof air barrier need to be planned.

As a fifth-generation builder, I believe that craftsmanship includes the work you’ll never see once the house is finished. These details help protect the investment you’re making and support a more comfortable, efficient home.

Planning a custom home in Rhode Island? Contact MacPherson Building to talk about the materials and building practices that go into your project.