While installing a suspended ceiling in the basement of my 17 year old house, I noticed that one of the floor joists (2"x10") has several significant cracks. I have a few pictures but I dont think you can post them to this site. The cracks are about 4 inches in length and extend clear through to the joist. The cracks, which are in the middle of the joist (width-wise) are quite wide (you can see through one). They do not extend to the top or bottom of the joist, and the joist is not deflecting. The top of the joist is glued to the subfloor and there does not appear to be separation from the subfloor. It's unclear whether the cracks are "original" or were caused by other factors. The joists are 16" on center.

If I could easily sister another joist, I would, but the suspended ceiling would have to be removed, and wires and pipes are also in the way.

Diagnosis? Suggestions?

 

Sistering is always an alternative. Post us a couple of pix on a site such as photobucket.com and give us the urls. We'd like to see what you see.

 

Per your request, I have posted several pics of the cracked floor joist on Photobucket.com. I hope the URLs below work. Thanks for your help - much appreciated!

http://i268.photobucket.com/albums/j...n/floor014.jpg
http://i268.photobucket.com/albums/j...n/floor013.jpg
http://i268.photobucket.com/albums/j...n/floor012.jpg
http://i268.photobucket.com/albums/j...n/floor010.jpg
http://i268.photobucket.com/albums/j...n/floor008.jpg
http://i268.photobucket.com/albums/j...n/floor006.jpg

 

Those are the weirdest checks I have seen in that type lumber. I don't think you would have a problem, but alot of weight could cause the checks to increase. Sistering is a simple solution and you could sleep better at night. As close together as these are, I would think you could get by with a 4' (longer the better) sister. Lay it flat and slide it up and into the void above the drop ceiling grid, then turn it on its side. You will need to bolt the sister to your existing joist using 3 1/2" x3/8" carriage bolts in about 4 or 5 places, staggering them as you go. Drill a 7/16" hole through both pieces and insert the bolts. From what I see, you don't have any pipes or other obstacles to keep you from sliding one of the sisters in. Let us know if this is doable, or how it goes with the repair.

 

I will give it a shot and let you know how it works out. I spoke with a friend that worked as a carpenter for about 10 years and he agrees that its probably not an issue but that a short sister would be a good idea.

Thanks for your help.

 

You have seen the cracks, and you will not forget them unless you do something positive, so it can't hurt to put in the sisters. Warm and fuzzy feeling.

 

Those are indeed some unnatural checks/cracks. It makes me wonder if the board wasn't unduly stressed, maybe during offloading, and nearly broke in two. That might explain the snap; cross-grain in the knotty, weaker part of the board; while the better grain top and bottom held the board together. Just a thought.
Steve