[prob. f. BRANDER sb.2, as if ‘to arrange cross-bars in the form of a gridiron’; but cf. F. brandir under BRANDED ppl. a.2]

1

  Hence Brandering vbl. sb., ‘the covering of the under-side of joists with battens … to nail the laths to, in order to secure a better key for the plaster of a ceiling’ (Spon, Dict. Engineer., 1869.)

2