Poutre vs. poutrelle

In French architecture and construction terminology, 'poutre' and 'poutrelle' both refer to structural components known as beams or girders. While similar, these terms refer to elements of different sizes and applications within a structure.

Poutre

A 'poutre' is a large, main beam or girder used in construction to support structures such as floors, roofs or bridges. It is usually substantial in size and carries significant loads.
La poutre principale de la charpente est en chêne.
(The main beam of the framework is made of oak.)
Les poutres soutiennent le poids du toit.
(The beams support the weight of the roof.)

Poutrelle

A 'poutrelle' refers to a smaller beam or girder, often used in conjunction with larger beams (poutres) for additional support in buildings or structures. Poutrelles are usually secondary elements that might support floors or roofing but carry lesser loads compared to poutres.
Des poutrelles métalliques ont été installées pour renforcer l'étage.
(Metal beams were installed to reinforce the floor.)
Nous utiliserons des poutrelles pour soutenir la nouvelle terrasse.
(We'll use joists to support the new deck.)

Summary

While both 'poutre' and 'poutrelle' refer to beams or girders in French construction vocabulary, the key difference lies in their size and structural responsibility. 'Poutre' refers to a main, large beam that plays a crucial role in supporting significant loads, whereas 'poutrelle' refers to a smaller, often secondary beam used to provide additional support within a structure.