Trimmer (construction) explained

In light-frame construction, a trimmer is a timber or metal beam (joist) used to create an opening around a stairwell, skylight, chimney, and the like. Trimmers are installed parallel to the primary floor or ceiling joists and support headers, which run perpendicular to the primary joists.^{[1] [2]}

It can also refer to a jack stud that supports a header above a window or door opening.

Traditionally, a stud which was less than full length was sometimes referred to as a cripple.^{[3] [4] [5]}

Notes and References

1. Web site: Architectural Graphic Standards Online. 2016-07-25.
2. Book: Ching, Francis D. K.. Building Construction Illustrated, 3rd Edition. John Wiley & Sons, Inc.. 2001. 0-471-35898-3. 4.21, 4.31. registration.
3. https://www.buildeazy.com/building_glossary-c.html Glossary, building terms, word definitions. Define Cripple Stud
4. https://www.pbs.org/hometime/glossary/frame.htm Hometime Glossary – Framing
5. http://www.doityourself.com/stry/buildingwallstudwind Building a Wall 3 - Three Stud Corner and Windows | DoItYourself.com