ashlaring

Ashlaring consists of short vertical timbers installed between floor joists and roof rafters in attic or garret spaces. These pieces fill the triangular or irregular voids created where the sloping roof plane meets the horizontal floor structure, converting dead space into usable floor area while maintaining structural continuity. The studs are typically the same depth as the main framing members but cut to whatever length the geometry demands, often ranging from a few inches to several feet depending on roof pitch and floor height.

The name derives from the Old English and French tradition of ashlar work, referring to stones or materials laid to fill gaps or complete a pattern. In carpentry, ashlaring performs a similar function: it completes the structural envelope and provides bearing surfaces for flooring, wall framing, or storage platforms in low-headroom attic zones. This technique became especially common in residential work during periods when attic spaces were being converted from storage into bedrooms or offices.

Structural role and installation

Ashlaring must be properly fixed to resist racking forces and wind loads transmitted through the roof. Each piece typically bears at one or both ends on the floor joist below and the rafter above, creating a stable triangulated connection. In modern framing, ashlaring is often toe-nailed or fitted with metal plates; historically, it was notched and pegged. The studs themselves remain unstressed members so long as the roof and floor systems are properly braced independently.

Problems arise when ashlaring is undersized, omitted entirely, or installed with gaps. This creates soft spots in attic floors, increases deflection under load, and can concentrate stress at isolated bearing points. Conversely, ashlaring cannot substitute for proper collar ties or ridge bracing if the roof structure is underdesigned. The presence of ashlaring does not reduce the need for traditional roof bracing systems.

In survey and renovation work, ashlaring condition is a useful diagnostic: missing or deteriorated pieces often indicate earlier settlement, roof movement, or structural repairs. Well-executed ashlaring is usually invisible to occupants but critical to the longevity of attic framing, particularly in steep-pitched roofs where the voids are largest and the structural demands highest.