roof tree

9.6

A strong beam that supports a roof or a tree growing high above a building

noun

Specialized

: viga de techo

The old cottage still had its original roof tree supporting the entire structure.

Examples

Birds nested in the roof tree, hidden high above the ground.
The roof tree supports the entire structure.
After the storm, the roof tree was badly damaged and needed replacement.
They installed a new roof tree last summer.
The old cottage still had its original roof tree supporting the entire structure.
After the storm, the roof tree was badly damaged and needed replacement.
They installed a new roof tree last summer.

Synonyms

beam

vsroof tree

104 2.7

A long strong piece of wood, metal, or concrete that supports part of a building

is more specific to the roof ridge and can also mean a tree on a roof

rooftree

vsroof tree

Archaic

9.9

A beam along the top ridge of a roof that supports the rafters

is specific to the roof ridge or also refers to a tree growing on a roof

How Strong

truss

Specialized

3 7.4

roof tree

Specialized

9.6

rafter

29 4.6

purlin

Specialized

1 9.6

batten

1 8.8

Surface Forms

roof tree singular

roof trees plural

Morphology

roof + tree

While the constituents 'roof' + 'tree' allow a literal, transparent reading (a tree on a roof) that a B1 learner could infer, the cited primary sense — a technical/main beam supporting the roof — is a specialized, lexicalized or metaphorical use not predictable from the parts. The combination therefore has some compositional clarity but also an opaque, jargon-like sense, so overall it is partially but not fully transparent.

Etymology

The name roof tree comes from old builders who called the big, strong beam that holds a roof a tree because it looked like a tree trunk. So roof tree now means the main beam that supports a roof, and the same image can also describe a real tree growing high on or above a roof.