Definition

Noun: - A structural arch: A "trimmer arch" is a small, flat or slightly curved brick arch constructed within a wooden floor frame. It is built between two supporting beams called trimmers to carry the load of a heavy, non-combustible hearth (the floor area in front of a fireplace) or chimney breast, transferring its weight to the main floor joists.

Usage

• Primary Context: The term is used almost exclusively in the fields of building construction, architecture, and historical building restoration.
• Typical Sentence Structure: It is used to describe a specific architectural component.
  • The renovation revealed an original trimmer arch supporting the 19th-century fireplace.
  • When installing a new hearth, ensure a proper trimmer arch is in place to bear the load.

Examples

Advanced Usage

• Historical Significance: In older buildings, trimmer arches are a common feature of solid fuel fireplaces. Their condition is often assessed during building conservation projects.
• Structural Role: The arch functions by converting the downward force of the hearth into outward thrust, which is contained by the trimmer beams, effectively bridging an opening in the floor joists.

Variants and Related Words

• Trimmer (n): A beam (joist) that runs perpendicular to the main floor joists to frame an opening, such as for a staircase or fireplace. The trimmer arch is built between two of these.
• Trimmer Joist (n): Synonym for "trimmer."
• Hearth (n): The floor of a fireplace, often made of brick, stone, or tile, whose weight is supported by the trimmer arch.
• Corbel Arch (n): A different, often older, type of arch constructed by corbelling (overlapping) bricks or stones. Unlike a true arch, it does not use a keystone.

Synonyms

• Supporting arch (general term)
• Hearth arch (descriptive term, less technical)

Notes

• This is a highly specialized architectural term. In modern construction with prefabricated fireplaces and different building codes, the traditional trimmer arch is less commonly encountered.
• It is not a decorative arch but a hidden structural element within the floor assembly.

Noun

1. an arch built between trimmers in a floor (to support the weight of a hearth)