Hi. Be gentle with me, I have no real idea what I'm talking about but need advice. We had kitchen extension 3 years ago , rsj installed where external wall opened up. The builders overlifted? When installing or propping causing the roof tiles to lift and a crack in the bedroom walk that runs at 90 degrees to installed rsj. The crack was very fine but about 1metre long from top of roof to top of bedroom door. My concern is the frack has got wider although in fairness is still quite thin...1 to 2mm? My husband tells me it is fine as the crack was caused by the over lifting and is now a weak point....It just worries me like mad . There is no other cracking. Any advice? Please dont start telling me how rubbish the builders were, it is what it is and I just need to deal with what we have. The work was inspected by building inspector at the time. Thanks niky