Brick Jack Arch Floor
Shallow segmental brick arches sprung between parallel beams, filled over to a level floor. The nineteenth-century mill floor, and a form now revisited where an exposed masonry soffit is wanted for thermal mass.
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.
The fireproof mill and warehouse floor of nineteenth-century Britain
Process
Feedstock
Fired clay
New or reclaimed clay brick, laid in lime mortar between steel or timber beams
Process heat
Kiln-fired
Brick is kiln-fired and lime mortar is calcined. The form is materially efficient for its span, but the components are both high-temperature products and no figure is claimed for either.
Binder
Lime
Fabrication
Site-formed
Sourcing: brick regionally or nationally sourced; the floor is built in place
Who Builds It
Specialist trade
Rare in the UK
Needs centring for each arch and a bricklayer used to arch work. Slow compared with a slab, and the programme has to allow for it
End Of Life
Separable
Lime mortar lets the brick be recovered; the beams come out separately
Maintenance: Repointed in lime; individual arches can be taken down and rebuilt
Specification Risk
What a specifier has to resolve before this can be built.
- Certification
- No standard design route in current codes; engineered case by case
- Fire
- Non-combustible — this was the original reason for the form
- Warranty
- Workmanship warranty only
- Insurance
- Not normally an issue where engineered
- Supply
- Bricklayers competent in arch work are limited outside conservation
Read This Honestly
- •Brick is kiln-fired and lime is calcined. This is not a low-processing floor; its case is structural form and exposed thermal mass.
- •The end bays need a tie or a buttress for the unresolved thrust. This is the detail that gets missed.
- •Heavy. The supporting beams and foundations carry more than they would under a timber floor.
Design & Specification Notes
Shallow segmental brick arches sprung between parallel beams, filled over to a level floor.
Material Note
A compression floor between beams, so the brick works in the only way brick is good. The exposed soffit is doing two jobs — structure and exposed thermal mass — which is usually the reason it is chosen.
Typical Uses
- •Primary frame
- •Long-span elements
- •Load-bearing supports
Key Performance
High load-bearing capacity for primary frame.
Specification Actions
- •Establish the brick source and whether reclaimed or new stock is intended; both are used and they are different propositions.
- •Have the lateral thrust at the end bays resolved explicitly — the end arch has nothing to push against but the perimeter.
- •A lime-mortared arch releases its brick at end of life; specify lime, not cement, if that matters.
Indicative Health & Indoor Air
Fired clay and lime mortar, inert in place.
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
- Shallow brick arches between beams, soffit exposed
- Service life
- 150 years