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Thin-shell roofs & canopies
Curved shells, vaults and folded-plate roofs that span without internal columns and use far less concrete than a flat slab of the same reach.
Services / Specialized
Ferro Concrete Design & Thin-Shell Construction
Ferrocement and thin-shell concrete for curved, sculptural and column-free forms — shells, vaults, folded plates, tanks and feature elements that standard beam-and-column contracting can't produce economically.
01 / Overview
Overview
Ferro concrete — more precisely ferrocement — is a thin, highly reinforced skin of cement mortar. Because the reinforcement is distributed through the whole section as fine mesh rather than concentrated in bars, the material can be formed into thin curved shells that carry load through their shape. That makes it the natural choice for domes, vaults, shell roofs, curved tanks and sculptural elements: forms that a conventional beam-and-column frame either cannot produce or can only produce at high cost and weight.
This service is for architects and clients with a specific curved or sculptural structure in mind, and for functional structures — tanks, canopies, long-span roofs — where a thin shell is simply the more efficient solution.
PBJ’s approach
PBJ Infra treats every thin-shell project as structural engineering before it is construction. The shell geometry is resolved for the spans and loads, the mesh and armature are designed layer by layer, and the mortar mix and its application sequence are specified — because with ferrocement the workmanship is the structure. PBJ’s dome-cottage cluster at AKAYA Resort in Gokarna is the built reference for this capability.
Technical considerations
- Form does the work: a thin shell is strong because of its curvature; flatten it and it needs far more material.
- Reinforcement layering: the number of mesh layers, their spacing and the armature bars are designed, not standardised.
- Application: mortar is applied and compacted in layers and cured carefully; rushing either step compromises the shell.
- Openings and edges: these are the stress concentrations and are detailed with extra reinforcement.
Related work
The most common form of this work is the ferrocement dome — the dome-cottage cluster at AKAYA Resort, Gokarna, is PBJ Infra’s example of the technique across a whole site — 10 dome cottages on a 10-acre resort, now in its final stage. The sculptural free-form entrance wall PBJ built for Mi Casa at Kanakapura shows the same curved-surface capability applied to a feature element rather than a shelter. Thin-shell structures on greenfield sites usually begin with land development.
02 / Scope
What ferro concrete design covers
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Sculptural & architectural elements
Free-form walls, staircases, screens and feature pieces where the shape is the design intent.
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Ferrocement tanks & water structures
Curved-wall water tanks and reservoirs, using ferrocement's long track record as a tank material.
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Dome structures
The dome is the most common thin-shell form PBJ builds — covered in detail on the dedicated ferrocement dome service.
03 / Advantage
Why PBJ for ferro concrete design
Ferro-concrete design underpins PBJ Infra's dome-cottage cluster at AKAYA Resort, Gokarna and its broader specialised structural work.
It is a distinct technical skill — reinforcement layering, mix design and application sequence differ from conventional RCC — and most contractors are not equipped for it.
Operating since 2018, GST- and UDYAM-registered, with a 5-year structural warranty.
04 / Process
How PBJ delivers ferro concrete design
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Consultation
Understand the form the client or architect wants and whether a thin-shell approach is the right way to achieve it.
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Design & planning
Shell geometry, reinforcement mesh and armature design, mortar-mix specification, and coordination with openings and services.
03
Construction
Formwork or armature, layered mesh, mortar application in controlled layers, curing, then finishing.
04
Handover
Structural inspection, waterproofing check and warranty documentation.
05 / Common questions
FAQ
Yes — ferro-concrete design, ferrocement domes and cob-house construction are part of PBJ's specialized services, alongside standard pool and building work.
Yes — the process includes 3D visualization and detailed planning before construction, so design and build stay with one team.
A 5-year warranty on structural work and a 2-year warranty on equipment, covering defects in materials or workmanship under normal usage conditions.
Cost depends on scope, size and finish level. PBJ doesn't publish fixed pricing — the project planner starts a consultation where a detailed, project-specific quote is prepared.
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