masonry control joints

[zennis]

I am mainly inquiring about how vertical control joints are installed at wall openings when a masonry bond beam spans/extends across the opening. How is a vertical CJ installed?

I have a small addition 50' x 30' that utilizes reinf. cmu behind a stone veneer and inside finish is mtl. stud/drywall, so the reinf. cmu is never visible. The 50' span has many door, window openings.

Thanks

 

[haynewp]

If the joint is above the opening then the bond beam will have to carry the entire load without help from corbeling action. If the joint is adjacent to the opening, see if you can specify that it shall be located a minimum distance from the end of all lintel beams so there will not be interference.

 

[jike]

The 50 foot dimension needs one CJ. The 30 foot dimension doesn't need any. Try to position the CJ in the center of the wall. Try to locate the CJ at the side of an opening, off the end of the lintel (So that the lintel does not restrain the movement). Large openings may require additional CJ's at each end to prevent cracking due to rotation of the lintel.

 

[JLNJ]

Your horizontal reinforcement may eliminate the need for any control joints in such a short wall and you won't need to ponder how your diaphragm chord will work with a joint in it.

 

[rgerk]

Zennis,

What I have encountered is control joints located at the end of a masonry lintel above the opening and then it turns toward the opening at the bottom of the lintel. The edge of the opening provides the movement below the lintel.

In other words, the control joint jogs around the lintel so as not to interrupt the lintel. Haynewp is right, the lintel will have to support the entire weight of the wall above if near a control joint.

 

[zennis]

Thank you all for the replies. Your replies help reinforce my thoughts on how the vertical cj would behave around a lintel opening.