Prefabricated Modular Building System with Large Format Compound Arched Roof Segments and Integrated Multi-Layer Insulated Ceilings

Abstract

Publication Abstract A modular building system incorporating large-format compound arched roof segments is disclosed. The system includes precast roof elements and cast in-situ foundation stones, structurally connected using post-tensioned cables and sealed with interlocking shiplap joints. No temporary propping is required during assembly. The invention enables rapid construction of scalable, architecturally expressive buildings with enhanced thermal performance. Roof segments may be fabricated from ultra-high-performance concrete or hemp-reinforced composites. Prefabrication improves production efficiency, build quality, and environmental outcomes. Applications include residential, commercial, and emergency housing. Publication Abstract A modular building system incorporating large-format compound arched roof segments is disclosed. The system includes precast roof elements and cast in-situ foundation stones, structurally connected using post-tensioned cables and sealed with interlocking shiplap joints. No temporary propping is required during assembly. The invention enables rapid construction of scalable, architecturally expressive buildings with enhanced thermal performance. Roof segments may be fabricated from ultra-high-performance concrete or hemp-reinforced composites. Prefabrication improves production efficiency, build quality, and environmental outcomes. Applications include residential, commercial, and emergency housing. 20 25 20 33 45 09 M ay 2 02 5 2 0 2 5 2 0 3 3 4 5 0 9 2 0 2 5 M a y 2 0 2 5 2 0 3 3 4 5 0 9 2 0 2 5 M a y 7 6 8 5 11 4 9 10 12 2 FIGURE 1 3 10 12 9 11 5 4 8 7 1 6 FIGURE 2 20 25 20 33 45 09 M ay 2 02 5 2 0 2 5 7 2 0 2 5 2 0 3 3 4 5 0 9 M a y E 1 0 1 2 2 F I G U R E 1 3 1 2 9 5 4 8 7 6 F I G U R E 2 2 0 2 5 7 2 0 2 5 2 0 3 3 4 5 0 9 M a y E 1 0 1 2 2 F I G U R E 1 3 1 2 9 5 4 8 7 6 F I G U R E 2

Claims

1. A prefabricated modular building construction system comprising:(a) A roof module constructed from precast and prefinished large format compound arched segments;(b) A roof module consisting of nine precast large-format segments, two cast in-situ foundation stones, and at least one precast column, together forming a double-ended gable compound arched architectural form;(c) A method of joining and sealing said segments using shiplap joints incorporating integrated gutters and sealing elements;(d) A method of structural interconnection using post-tensioning via a plurality of steel cables anchored to the foundation stones, thereby forming a unified monolithic shell;(e) An arrangement enabling multiple roof modules to be joined together to create expanded building forms with varied and configurable floor plans;(f) A method of erecting the roof segments, foundation stones, and column into a prefabricated building module;(g) A method of erecting said segments into a building module without the use of temporary propping;(h) Architectural features enabling flexibility in design and variation in aesthetic expression within a modular construction framework.

2. The system of claim 1, wherein the roof segments are constructed from a hemp fiber-reinforced mineral composite (HFRMC), comprising lime, clay, or other alkaline binder matrices.

3. The system of claim 1, wherein the precast and prefinished roof segments are constructed of ultra-high-performance concrete (UHPC), high-performance concrete (HPC) and / or earth friendly concrete (EFC).2025203345   09 May 20254. The system of claim 1, wherein the segments are formed from a non-mineral, thermoplastic composite using injection molding or thermoforming for lightweight, non-structural applications.

5. The system of claims 2-4, wherein the roof segments are cast using reusable large-format steel molds.

6. The system of claim 1, wherein each roof segment comprises a large-format, precast and prefinished multi-layer assembly including:(a) A structural roof layer formed from hemp fiber-reinforced mineral composite (HFRMC), ultra-high-performance concrete (UHPC), high-performance concrete (HPC), and / or earth friendly concrete (EFC).and prefinished with a penetrating waterproof membrane and a ceramic thermal insulating paint;(b) An insulation layer chemically and mechanically bonded to the underside of the structural layer;(c) An interior ceiling layer composed of a bio-resin infused hemp fiber composite coated with a sealing membrane and washable paint;(d) Integrated service conduits within the structural, insulation and / or ceiling layers;(e) Preinstalled ceiling infrastructure including lighting, smoke detectors, and fan brackets;(f) Optional integrated linear LED lighting within edge profiles of the segments.(g) Factory-installed mechanical, electrical, and plumbing (MEP) infrastructure embedded within structural, non-structural or insulation layers to reduce on-site installation.

7. The system of claim 1, wherein the method of assembly includes:(a) Conventional footings prepared prior to installation;(b) Foundation stone molds positioned by a licensed surveyor to an accuracy of >3mm.2025203345   09 May 2025(c) Conventional concrete pouring of foundation stones;(d) Columns fixed to footings and connected to roof segments via bolting;(e) Two segments lifted into place by crane and bolted to adjacent foundation stone;(f) One segment lifted into place by crane and bolted to top of column;(g) All other segments lifted into place by a crane and self-supporting without temporary propping;(h) Segment g is placed and bolted in place while held by a crane;(i) Soft post-tensioning applied progressively during erection for WPHS;(j) Final post-tensioning locks the structure into a self-supporting monolithic form.

8. The system of claim 1, wherein the structure is disassemblable, re-transportable, and capable of being expanded or financially secured as a physical commodity.

9. The system of claim 1, wherein the segment joints comprise:(a) A primary shiplap joint;(b) A rebate housing a compressible rubber seal;(c) A secondary internal rebate forming a gutter for redundancy in waterproofing;(d) A final seal applied using an external caulking compound.

10. The system of claim 1, wherein the segments are self-supporting during erection due to their geometry and the sequencing of segment installation.

11. The system of claim 1, wherein both foundation stones include cylindrical rebates for anchoring post-tensioning cables and securing shell segments mechanically.2025203345   09 May 202512. The system of claim 1, wherein roof modules are joined to form larger structures, comprising:(a) Intermodular segments formed from shortened molds with adjustable shutters;(b) Structural joins supported by precast walls or foundations;(c) Incremental site development capability;(d) Architectural continuity across modules via standardized interface dimensions.

13. A system for internal wall construction within a module or between joined modules of claim 1, comprising:(a) Internal walls cast from hempcrete using steel molds, incorporating preinstalled service conduits;(b) Cylindrical vertical cavities formed within the internal walls to permit concrete infill for structural integration when modules are joined;(c) An arched bond beam connecting the vertical cavities and providing structural support beneath adjoining roof segments at modular junctions;(d) A bond beam geometry contoured to match the underside profile of the roof segments to ensure continuous load transfer and alignment.

14. The system of claim 1, wherein the construction system supports CAD / CAM / CNC-based manufacturing using reusable precision steel molds.

15. The system of claim 1, wherein the structural design significantly reduces the reliance on corrosion-prone steel reinforcement by employing post-tensioned cable systems in combination with corrosion-resistant alternatives, including the use of hemp fibres—either short or long strand—as integrated reinforcement within composite shell segments to improve tensile strength and structural resilience.

16. The system of claim 1 enables large-scale manufacturing via CAD / CAM / CNC methods using reusable precision steel molds.2025203345   09 May 202517. The system of claim 1, wherein the structure may be erected as a roof-only shelter without the use of internal or external walls.

18. The system of claim 1, wherein timber veneers, woven fibers, or decorative hemp composites may be used within ceiling layers for architectural expression.

19. The system of claim 1 distinguishes itself from traditional construction methods such as tilt-up panels, off-form concrete, masonry blockwork, panelized framing, and geodesic structures by employing large-format, self-supporting compound arched segments that are structurally interconnected into a unified monolithic shell using a post-tensioned cable system.

20. The system of claim 1, wherein the construction system is adaptable to culturally specific architectural variants, including variations in roof pitch, number of segments, or segment geometry, while maintaining standardized structural interfaces and core engineering principles to ensure modular compatibility and structural integrity.

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