Timbrel Vaulting
Thin tiles laid flat in two or three overlapping layers with fast-setting mortar, built up freehand from the edges with little or no formwork. Also called Catalan, tile or Guastavino vaulting. It carries load in compression, so it needs very little material for the span.
Carbon and evidence
How This Is Made
An Environmental Product Declaration is issued by a manufacturer against a declared unit. This record has neither, so it states sourced facts about process and provenance instead of a carbon figure.
Catalan vaulting, carried to the United States by Rafael Guastavino from 1885 and revived in UK research and practice — the Pines Calyx dome in Kent (2005) is the best-known British example
Process
Feedstock
Fired clay
Thin fired-clay tiles, laid in two or three layers bedded in fast-setting mortar
Process heat
Kiln-fired
The tiles are kiln-fired and the mortar binder is calcined. The saving claimed for this technique is structural — far less material for the span — not a low-processing material. No figure is held for either.
Binder
Lime
Fabrication
Site-formed
Sourcing: tiles nationally or internationally sourced; the vault is built in place
Who Builds It
Specialist trade
Rare in the UK
Built freehand from the edges with little or no falsework, which is the technique’s great advantage — and it takes a vaulter who has done it before
End Of Life
Monolithic
A bonded shell; demolition breaks the tiles rather than releasing them
Maintenance: Repointed and patched in place; a compression shell is forgiving of local repair
Specification Risk
What a specifier has to resolve before this can be built.
- Certification
- No Agrement and no code path. Designed by compression-only analysis and demonstrated by test or precedent, which building control will need explaining
- Fire
- Non-combustible
- Warranty
- Workmanship warranty only
- Insurance
- Expect questions — an unfamiliar structural form with no standard design route
- Supply
- Very few practitioners in the UK. This is the binding constraint, not the material
Read This Honestly
- •The tiles are kiln-fired and the mortar is calcined. The argument for this technique is structural efficiency, not a low-processing material.
- •Guastavino’s system substituted Portland cement for the traditional lime and gypsum mortars. A cement-mortared vault is a materially different carbon proposition — confirm which is specified.
- •Thrust has to go somewhere. The buttressing or tie needed at the springing is part of the cost and part of the carbon.
Design & Specification Notes
Thin tiles laid flat in two or three overlapping layers with fast-setting mortar, built up freehand from the edges with little or no formwork.
Material Note
The efficiency is structural, not material: a compression shell spans on a fraction of the depth a flat floor needs. The tiles themselves are kiln-fired, and the record does not claim otherwise.
Typical Uses
- •Primary frame
- •Long-span elements
- •Load-bearing supports
Key Performance
High load-bearing capacity for primary frame.
Specification Actions
- •Establish the tile source and the mortar specification — a Portland cement mortar is a different proposition from a lime or gypsum one.
- •Get the shell geometry checked by an engineer familiar with compression-only analysis; it is not a conventional slab calculation.
- •Record it as monolithic — the shell is broken out at end of life, and the tiles do not come back whole.
Indicative Health & Indoor Air
Fired clay and lime mortar. Cutting tiles generates silica dust — a control for the vaulter.
Products in this category
6 products from 5 manufacturers · 8 in this category. Ordered by the evidence each record holds, never by commercial standing.
Specification
- Finish
- Layered thin tile, exposed soffit
- Service life
- 150 years