slats
A facade of parallel long, thin strips fitted flush against neighboring strips without overlapping.
A slat facade is composed of many individual long, thin, flat strips arranged parallel to each other and abutting each other along the edges. Unlike weatherboarding, the strips in a slat facade do not overlap; they are arranged flush against each other. Gaps are often prevented by joining boards with interlocking tongue-and-groove members, or with a more continuous layer of some material underneath.
The strips abut along their long edges. Tongue-and-groove joints or a continuous backing can close gaps without changing the flush arrangement.
Weatherboarding instead overlaps the strips. The arrangement of the edges determines this distinction even when the same material is used.