I am installing a wood stove (Werner W-130) in an unfinished basement. I have gone through NFPA 211 but i can not find the answer to clearances to non-combustibles. The basement floor is concrete so per 13.5.1.3 i should not need any added protection or clearance reduction. However, I can not find the minimum clearance to a non-combustible "wall". The surface behind the stove is the un-finished exterior of the chimney. Would this even be considered a "wall"? This is is a central chimney so the chimney itself is the only surface near the stove. Is there a minimum clearance needed from the concrete block chimney?