The Collaborative International Dictionary
Ashlering
Ashlaring \Ash"lar*ing\, Ashlering \Ash"ler*ing\, n.
The act of bedding ashlar in mortar.
Ashlar when in thin slabs and made to serve merely as a case to the body of the wall.
--Brande & C.(Carp.) The short upright pieces between the floor beams and rafters in garrets. See Ashlar, 2.
Wiktionary
ashlering
n. (alternative form of ashlaring English)