Cut timber (6)
(Other definitions for sawn that I've seen before include "timber must be" , "went up and down?" , "(Of wood) cut" , "Cut with serrated blade" , "Severed" .)
(Other definitions for lumber that I've seen before include "Burden with an unwanted task" , "Wood cut and prepared as building material" , "articles in storage" , "Sawn wood - be a burden to" , "Wood for building - saddle" .)