8' × 16' portable, monolithic hemp-geopolymer shelter kit
Design Package Rev 1.0 — Development SpecificationsThe Phyto-Fortress is the first building-scale demonstration of the Phyto-board® system: a timber skeleton carries the structural load, a reactive hemp-hurd geopolymer infill fills and locks the envelope together, and Phyto-board panels form the continuous interior and exterior skins. It ships as a shell — framed openings, skid base, and core envelope complete — with doors, glazing, HVAC, and interior fit-out left to the installer.
The reactive hemp-hurd geopolymer isn't a filler poured into a cavity — it's a chemical bonding system. The underlying chemistry class starts from five inputs: hemp hurd, crystalline silica, silanes, lime, and metakaolin.
| Step | Reaction |
|---|---|
| 1. Surface preparation | Hydroxyl (–OH) groups on hemp hurd and silanol (Si–OH) groups on silica become available for bonding |
| 2. Silane coupling | Silanes hydrolyze and bridge — one end bonds to hemp hurd, the other to silica |
| 3. Lime activation | Lime dissolves, releasing Ca²⁺ and OH⁻, raising pH to activate silica and metakaolin surfaces |
| 4. Pozzolanic reaction | Metakaolin dissolves in the high-pH environment; Si and Al species react with Ca²⁺ to form C-S-H and C-A-H hydrates |
| 5. Matrix formation | Hydrate gels grow and encapsulate the hemp hurd and silica, filling pores into a dense, low-porosity matrix |
Phyto-board's production formulation extends this baseline chemistry with additional coupling agents and activation chemistry, produced under in-process quality assurance controls, to reliably yield the HD, MD, and LT density grades used across the panel and Phyto-Fortress product lines.
Panel and wall-thickness figures are development targets pending final engineering (structural, thermal, fire). Tolerances: panel thickness ±1/16 in, panel length/width ±1/4 in, out-of-plumb ±1/4 in per 10 ft. Wind/impact values are design intent until confirmed by testing.
| Layer | Material | Function |
|---|---|---|
| 1 | HD Phyto-board exterior panel | Hydrophobic, impact- and weather-resistant surface |
| 2 | Offset 2×4 timber frame | Structural load path, thermal break |
| 3 | Reactive hemp-hurd geopolymer infill | Monolithic structural/insulating core, bonds to lumber and skins |
| 4 | Offset 2×4 timber frame (interior side) | Structural load path, thermal break |
| 5 | MD Phyto-board interior panel | Interior structural finish surface |
Offset framing on both faces leaves a continuous geopolymer core between them — this uninterrupted infill is what makes the wall act as one monolithic composite rather than a layered assembly.
| Item | Spec |
|---|---|
| Timber / engineered wood framing | 2×4, offset dual-frame per wall/roof/floor stack |
| Skid base | 8' × 16' timber skid, 9043-coated steel runners |
| Corner lifting / tie-down hardware | Integrated at skid corners |
| Item | Spec |
|---|---|
| HD exterior panel | 4' × 8', 5/8", light orange dye, hydrophobic |
| MD interior panel | 4' × 8', 5/8", dark blue dye |
| Item | Spec |
|---|---|
| Hemp hurd | Regionally processed, packaged in 40 lb vacuum bags |
| Crystalline silica (SiO₂) | Reactive filler / network strength |
| Silanes (organofunctional) | Coupling agent — bridges hemp hurd and silica/alumina |
| Lime (Ca(OH)₂) | pH activation, pozzolanic reaction |
| Metakaolin | Aluminosilicate binder component |
| Quikcrete or equivalent | Sourced locally at assembly site — not shipped |
| Item | Spec |
|---|---|
| Structural connectors | Conventional, per engineering spec |
| Hurricane straps | Top plate to roof structure (Intermediate/Tier One) |
| Reinforced anchor connections | At skid |
| Item | Spec |
|---|---|
| Small radius corner mold | R 1½" (38 mm), one-piece, reusable |
| Large radius corner mold | R 6" (152 mm), split/reusable |
| Item | Spec |
|---|---|
| Fasteners | Per assembly guide |
| Vapor / weather components | As required by climate configuration |
| Tools & accessories | Mix, placement, and finishing tools (kit-supplied) |
| Doors / windows / glazing | Kit-supplied hardware; install by local labor |
| Item | Spec |
|---|---|
| Assembly guide | Included, sequence-numbered |
| Component packaging | Organized by assembly sequence and identification tags |
Not shipped — sourced locally at the build site: water and Quikcrete (or equivalent) for geopolymer mixing, and local assembly labor.
Economical timber-frame shell with Phyto-board envelope and simple skid connection.
Adds hemp scrim reinforcement, hurricane straps, stronger opening blocking, and reinforced anchor connections.
Adds a protected internal steel storm core with reinforced opening frame, roof tie rail, diagonal tension strap, and steel-reinforced sill connection.
Specifications compiled from Phyto-Board design package materials (Rev 1.0, 14 Aug 2025) and the 8×16 Phyto-Fortress kit diagrams. Panel thickness shown at 5/8" for this pamphlet; final thickness and density are engineered per site conditions and load requirements. Wall/roof/floor totals marked "nominal" are subject to structural, thermal, fire, and code-compliance testing — confirm current values before publishing to a formal spec sheet or grant submission.