Cracks in joist

clydesdale

One of the 2x10 joists in my basements has cracks in it. Each crack is roughly 3-4' in length but only appears on one side of the joist. The other side of the joist is smooth. The side with the cracks has a heat duct running parallel to it. There are no holes or notches in the joist. No other joist in the basement has any cracks. Joist is level with no sagging. Should I get out in front of this potential problem and sister the joist with some 2x10's? Would I have to use a joist the same size as the original joist? I am concerned that it might be tough to get a full size joist in place with the existing utility lines and framing. I have access to the joist from both an unfinished part of the basement as well as a finished part with a drop ceiling.

epson

The reason your floor joist is cracked on one side is because you have the heating duct running parallel with it and the heat is extracting the moisture out of the joist and thus the cracking. Is there any way you can put a heat shield there preventing further moister loss? If not then you can sister the joist but you will have the same problem down the line because of your heat duct.

clydesdale

Thanks for the response. Right now that duct is not insulated. Would some duct insulation help the situation or do I need some other heat shield product? Probably ought to insulate the duct anyway -

epson

yeah that would work...

Ron6519

All you have is some checking of the lumber. It doesn't effect the structural aspect of the joist.
Heating ducts should be insulated and the joints sealed with metal tape.
Ron