STRUCTURALLY INSULATED PANEL (SIP)SYSTEM
Avoid Common Problems
These double sheathed, foam core wall panels are processed off-site, and then assembled like lego in a fraction of the time at the job location. For sheathing, common materials include a variety of cementitious boards, magnesium boards, oriented strand board (OSB), plywood, and even metal.
The fault in the SIP structure design lies in the lack of care given to the plates (the horizontal lengths that run under the bottom and on top of the panels) and splines (the vertical connections between panels). Because there is a lack of vapor barrier at these vulnerable intersections, energy and moisture transference is inevitable. The result is mold formation, leaking and cracking. Knowing this, Hulks SIP System is designed to tackle these joints from inside out, eliminating the problems, and brings these structures close to zero energy loss (NET 0).
Step 1
Hulk MBS
Step 2
Hulk Mastic
Step 3
Hulk WP
Class "A"
Quicklinks
Step 4
Hulk SRT
Hulk System - Installation
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Waterproofing Challenges Unique to SIP Construction
Structurally Insulated Panels present specific waterproofing challenges that standard membrane systems are not designed to address. SIP construction uses cementitious sheathing and panel joints at regular intervals — and those joints, along with underground panel-to-footing connections, are the primary entry points for water. A continuous membrane that bridges every joint and transition is essential; any system that relies on tape or mechanical fasteners at these locations will eventually fail as the building moves and settles.
The Hulk SIP Waterproofing System
Hulk Systems’ approach to SIP waterproofing focuses on eliminating water access at the two most vulnerable points: cementitious sheathing faces and underground joints. Hulk STPE® is applied at all panel joints, penetrations, and below-grade transitions as a flexible, adhesive-based air and water barrier that moves with the structure. The Hulk WP spray membrane is then applied as the primary waterproofing layer across the full surface, creating a seamless composite that treats the SIP assembly as a single waterproofed unit rather than a series of individually sealed components.
Above Grade & Below Grade
SIP buildings typically require waterproofing both above and below grade. Below grade, the focus is hydrostatic water resistance at panel joints and the foundation transition. Above grade, the system shifts to weather barrier and vapor management — preventing bulk water entry through the sheathing while allowing the wall assembly to dry. Hulk Systems can specify the appropriate products for both zones on the same project, ensuring continuity of protection from the footing to the top of the wall.
Project Consultation
SIP waterproofing requires project-specific system selection based on panel type, sheathing material, climate zone, and below-grade depth. Contact Hulk Systems to discuss your SIP project — we provide specification support, technical data sheets, and licensed applicator installation across Canada.
For SIP waterproofing, Hulk Systems commonly specifies Hulk STPE Sealant at panel joints and transitions alongside the primary Hulk WP membrane. See related systems including the Concrete System and ICF Block System. Download application documentation from the Resources page or contact Hulk Systems for project support.