What does batt mean?
A batt is a flat, rectangular layer of soft, matted fibers—most commonly fiberglass, mineral wool, or cotton—used for insulation, padding, or filling. In building construction, batts are sold in standardized widths designed to fit snugly between wall studs, floor joists, and rafters, making them one of the most familiar forms of home insulation. In textiles, a cotton or wool batt serves as the padding inside quilts, comforters, and upholstered pieces, where quilters more often speak of 'batting.' The word belongs largely to trade vocabulary: contractors, insulators, and quilters use it daily, but it rarely appears in casual conversation. Its meaning is straightforward—a single sheet or layer of fibrous material—and its usefulness lies in describing precisely that unit of material, distinguishing one cut piece from the bulk roll it came from.
nounA batt is a flat, rectangular piece of soft material—such as cotton, wool, or fiberglass—that has been matted or layered together, used especially for insulation, padding, or quilting.
- A flat sheet of matted or loosely woven material such as fiberglass, mineral wool, or cotton, used chiefly as insulation in building construction.
- A layer of soft fibrous material, such as cotton or wool, used as padding or filling in quilting and upholstery.
"The contractor fitted each fiberglass batt snugly between the wall studs before hanging the drywall."
"Rolls of mineral-wool batt were stacked in the garage, ready to be cut to fit between the joists."
"She smoothed a cotton batt over the quilt backing before pinning the layers together."
Standard plural; used when referring to multiple sheets or layers of insulating or padding material.
"The crew installed two dozen batts in the attic before lunchtime."
That fluffy pink roll in your attic has a name of its own: each slice is a 'batt,' and builders have been tucking them into walls for over a century.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of batt
The origin of batt is uncertain, though it appears to have developed in English, likely by the early nineteenth century, in connection with prepared sheets of wool or cotton fiber. It may be related to the word 'bat' in some of its older senses, but no definitive derivation has been established. The term became firmly associated with building insulation as fiberglass and mineral-wool products spread through the construction industry in the twentieth century.
How batt is actually used
Batt is a technical term most often heard in construction and textile trades rather than everyday conversation. In American usage it commonly refers to fiberglass or mineral-wool insulation sold in standard widths; among quilters, the related term 'batting' is more frequent.
Easily confused with batt
A bat is an animal, a sports implement, or the verb to hit, whereas a batt is specifically a flat layer of matted insulating or padding material.
Batting is the soft filling material itself (as in quilts), while a batt is one pre-cut sheet or layer of that material.